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Resumen El objetivo del presente artículo fue evaluar la respuesta ovárica y embrionaria de dos protocolos hormonales de superovulación en bovinos altoandinos Pardo Suizo. Se utilizaron cuatro vacas donantes mediante un diseño de series temporales interrumpidas con replicaciones cambiadas y cada vaca fue sometida a dos protocolos hormonales de superestimulación: protocolo 1 (Prot.1, FSH convencional de 400mg en dosis decrecientes por cuatro días) y protocolo 2 (Prot. 2, eCG, 2500UI en dosis única). Durante la realización de los protocolos se hizo la evaluación ovárica de los folículos pre ovulatorios (FPO) y de los cuerpos lúteos (CLs) mediante ecografía. Así mismo se evaluó la calidad y tasa de embriones recuperados. Los resultados mostraron que el número y diámetro de FPO y CLs no mostraron diferencias significativas entre los protocolos; de la misma forma en el número de embriones colectados. Con eso se concluye que ambos protocolos de superovulación (FSH y eCG) son aplicables en bovinos pardo suizo altoandino. Abstract The present study evaluated the ovarian and embryonic response of two hormonal superovulation protocols in high Andean Brown Swiss cattle. Four donor cows were used using an interrupted time series design with switched replications where each cow was subjected to two hormonal superstimulation protocols: protocol 1 (Prot.1, conventional FSH of 400mg in decreasing doses for four days) and protocol 2 (Prot. 2, eCG, 2500IU in a single dose). During the implementation of the protocols, the ovarian evaluation of the preovulatory follicles (POF) and the corpora lutea (CLs) was carried out by ultrasound. Likewise, the quality and rate of recovered embryos were evaluated. The results showed that the number and diameter of FPO and CLs did not show significant differences between the protocols, in the same way the number of embryos collected. With this, it is concluded that both superovulation protocols (FSH and eCG) are applicable in Brown Swiss High Andean cattle.

In brief Maternal obesity can impair metabolism in the embryo and the resulting offspring. This study shows that metabolic disruptions through α-ketoglutarate may link altered metabolism with epigenetic changes in embryos. Abstract Maternal obesity can impair offspring metabolic health; however, the precise mechanism underpinning programming is unknown. Ten-Eleven translocase (TET) enzymes demethylate DNA using the TCA cycle intermediary α-ketoglutarate and may be involved in programming offspring health. Whether TETs are disrupted by maternal obesity is unknown. Five to six week-old C57Bl/6 female mice were fed a control diet (CD; 6% fat, n = 175) or a high-fat diet (HFD; 21% fat, n = 158) for 6 weeks. After superovulation, oocytes were collected for metabolic assessment, or females were mated and zygotes were cultured for embryo development, fetal growth, and assessment of global DNA methylation (5-methylcytosine (5mC), 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxycytosine (5caC)) in the two-cell embryo. Zygotes collected from superovulated CBAF1 females were cultured in media containing α-ketoglutarate (0, 1.4, 3.5, or 14.0 mM) or with 2-hydroxyglutarate (2HG) (0 or 20 mM), a competitive inhibitor of α-ketoglutarate, with methylation and blastocyst differentiation assessed. After HFD, oocytes showed increased pyruvate oxidation and intracellular ROS, with no changes in Tet3 expression, while two-cell embryo global 5hmC DNA methylation was reduced and 5fC increased. Embryos cultured with 1.4 mM α-ketoglutarate had decreased two-cell 5mC, while 14.0 mM α-ketoglutarate increased the 5hmC:5mC ratio. In contrast, supplementation with 20 mM 2HG increased 5mC and decreased 5fC:5mC and 5caC:5mC ratios. α-ketoglutarate up to 3.5 mM did not alter embryo development, while culturing in 14.0 mM α-ketoglutarate blocked development at the two-cell. Culture with 2HG delayed embryo development past the four-cell and decreased blastocyst total cell number. In conclusion, disruptions in metabolic intermediates in the preimplantation embryo may provide a link between maternal obesity and programming offspring for ill health.

Introduction: The present study was based on the microinjection of lentiviruses into chicken embryos in the laboratory to demonstrate loss function phenotype in chicken embryonic development. Method: This study aims primarily to demonstrate that small interfering RNAs can act effectively on chicken embryonic development by decreasing function of the chicken sphingosine 1 phosphate receptor 1/endothelial differentiation gene 1 (S1P1/EDG-1) during embryogenesis. In addition, chicken embryo fibroblasts (CEF) were prepared, plasmid gene 3132/PLL3.7 was used with 2XHBS for transfection, virus titer was determined prior to virus microinjection into chicken embryos to see the loss-of-function phenotype. Results: The results obtained after viral microinjection showed that the function of S1P1/EDG-1 gene was progressively reduced from the second day of egg incubation until the fourth day. After the fifth day of incubation, loss of gene function was more marked by bleeding into the embryo sac. Conclusion: Results from previous studies on other vertebrates such as mice have showed similar results [1, 2].

One of the major problems impeding the sustainable development of goose production is low egg hatchability. Thus, it is imperative to develop more efficient ways to improve the hatching qualities of goose eggs. The present study aimed to investigate the effects of changes in the temperature regime of incubation on the availability of vitamins A (retinol) and E (α-tocopherol), as well as important elements of antioxidant protection in embryos and goslings. The initial heating of eggs at temperatures of 39 and 39.5 °C during the first 24 or 36 h was used as the main factor influencing goose embryo development. The dynamics in the content of antioxidant retinol and α-tocopherol were analyzed in the liver of embryos and goslings (up to 9 days of age) using the standard regime of incubation (at 38 °C) and the prior heating of eggs (at 39 °C and 39.5 °C) in the first 24 and 36 h of incubation. The obtained results provided new information about the effect of the initial heating of eggs on the function of antioxidants in the gosling’s body. It was confirmed that the age-related changes of retinol and α-tocopherol levels in goslings are similar to those found in chicks, ducklings, and turkey-poults. In addition, the effect of an egg’s weight on hatchability was established, with the hatchability of eggs in the medium weight class being higher than that of smaller and larger eggs. The efficiency of the redistribution of retinol from the yolk to the liver in day-old goslings was higher by 6% when exposing eggs to a temperature of 39.5 °C for 36 h. The initial heating regime at 39.5 °C led to an increased hatch of goslings, and to the evenness of their hatch from eggs of different weights, approaching the hatch values of the medium class. Overall, the α-tocopherol concentration in the liver of embryos and goslings, using the starting heating of eggs, was higher than that with the standard temperature mode of incubation. At the same time, the hatch rate of goslings increased by 9–13%, and the hatchability of eggs by 10–16%. For use in the practice of hatcheries and breeding poultry farms, it is recommended that goose eggs are heated for 36 h at 39.5 °C.

Metronidazole is the primary antimicrobial drug for treating acute and chronic vaginal pathogens during pregnancy; however, there has been insufficient research on placental disorders, early pregnancy loss, and preterm birth. Here, the potential activity of metronidazole on pregnancy outcomes was investigated. 130 mg/kg body weight of metronidazole was orally given individually to pregnant rats on gestation days 0–7, 7–14, and 0–20. Pregnancy outcome evaluations were carried out on gestation day 20. It was demonstrated that metronidazole could induce maternal and fetal hepatotoxicity. There is a significant increase in the activities of maternal hepatic enzymes (ALT, AST, and ALP), total cholesterol, and triglycerides compared with the control. These biochemical findings were evidenced by maternal and fetal liver histopathological alterations. Furthermore, metronidazole caused a significant decrease in the number of implantation sites and fetal viability, whereas it caused an increase in fetal lethality and the number of fetal resorptions. In addition, a significant decrease in fetal weight, placental weight, and placental diameter was estimated. Macroscopical examination revealed placental discoloration and hypotrophy in the labyrinth zone and the degeneration of the basal zone. The fetal defects are related to exencephaly, visceral hernias, and tail defects. These findings suggest that the administration of metroniazole during gestation interferes with embryonic implantation and fetal organogenesis and enhances placental pathology. We can also conclude that metronidazole has potential maternal and fetal risks and is unsafe during pregnancy. Additionally, it should be strictly advised and prescribed, and further consideration should be given to the associated health risks.

Simple Summary Antimicrobial drugs, in addition to exerting antibiotic, antifungal, antiparasitic, or antiviral effects, may also affect the central nervous system and gut microbiota, thereby modulating brain and behavior. Zebrafish models can be used for studying the effects of antimicrobial drugs on the central nervous system. Here, we discuss recent findings on using zebrafish for assessing the effects of a wide range of antimicrobial drugs on brain and behavior in vivo. Antimicrobial drugs represent a diverse group of widely utilized antibiotic, antifungal, antiparasitic and antiviral agents. Their growing use and clinical importance necessitate our improved understanding of physiological effects of antimicrobial drugs, including their potential effects on the central nervous system (CNS), at molecular, cellular, and behavioral levels. In addition, antimicrobial drugs can alter the composition of gut microbiota, and hence affect the gut-microbiota-brain axis, further modulating brain and behavioral processes. Complementing rodent studies, the zebrafish (Danio rerio) emerges as a powerful model system for screening various antimicrobial drugs, including probing their putative CNS effects. Here, we critically discuss recent evidence on the effects of antimicrobial drugs on brain and behavior in zebrafish, and outline future related lines of research using this aquatic model organism.

Simple Summary Antimicrobial drugs, in addition to exerting antibiotic, antifungal, antiparasitic, or antiviral effects, may also affect the central nervous system and gut microbiota, thereby modulating brain and behavior. Zebrafish models can be used for studying the effects of antimicrobial drugs on the central nervous system. Here, we discuss recent findings on using zebrafish for assessing the effects of a wide range of antimicrobial drugs on brain and behavior in vivo. Antimicrobial drugs represent a diverse group of widely utilized antibiotic, antifungal, antiparasitic and antiviral agents. Their growing use and clinical importance necessitate our improved understanding of physiological effects of antimicrobial drugs, including their potential effects on the central nervous system (CNS), at molecular, cellular, and behavioral levels. In addition, antimicrobial drugs can alter the composition of gut microbiota, and hence affect the gut-microbiota-brain axis, further modulating brain and behavioral processes. Complementing rodent studies, the zebrafish (Danio rerio) emerges as a powerful model system for screening various antimicrobial drugs, including probing their putative CNS effects. Here, we critically discuss recent evidence on the effects of antimicrobial drugs on brain and behavior in zebrafish, and outline future related lines of research using this aquatic model organism.

Digital, The effect of L-165041 (PPARδ-agonist) on decreasing apoptosis and intracellular lipid content was assessed in fresh and vitrified–warmed in vitro-produced bovine embryos. It was hypothesised that the addition of L-165041 to the culture medium enhances development and cryopreservation. Oocytes were allocated to one of two treatments: control-standard culture medium, or L-165041 added to the medium on day 1 with no media change. Ultrastructure, cleavage, and blastocyst rates were evaluated in fresh, and in post-vitrification cultured embryos by optical and electronic microscopy. A subset of fresh embryos were fixed for TUNEL assay and for Sudan-Black-B histochemical staining. Vitrified–warmed embryos were assessed using MALDI-MS technique. Cleavage and blastocyst rates (control 49.4 ± 5.2, L-165041 51.8 ± 4.3) were not influenced by L-165041. The proportion of inner cell mass cells (ICM) was higher in fresh embryos, and the rate of total and ICM apoptosis was lower in L-165041. In warmed-embryos, total and ICM apoptosis was lower in L-165041. The overall hatching rate was higher in L-165041 (66.62 ± 2.83% vs 53.19 ± 2.90%). There was less lipid accumulation in fresh L-165041-embryos. In conclusion, the use of L-165041 is recommended to improve the viability of in vitro-derived bovine embryos., Ciencias Agropecuarias

In order to determine the pollinizer success rates between twelve apple cultivars in 2021 and 2022, 671 apple embryos were collected from 19 different orchards in Ullensvang (southwestern Norway) and Svelvik (southeastern Norway). Genomic DNA was extracted from the collected embryos and, afterward, a genetic characterization with 15 polymorphic microsatellite markers was conducted. An identical set of markers was also used on all twelve mother cultivars, as well as on six crabapple pollinizers, which were found in the investigated orchards. The obtained molecular data enabled paternity analyses to be performed with the objective of assigning a male parent to each embryo. The paternity analyses identified pollen donors for all, except for 3% of the embryos. In most cases, it was possible to identify the most successful pollinizers for each cultivar, with ‘Aroma’ and ‘Discovery’ being the most efficient pollen donors overall. Tree abundance seems to be a major factor in pollinizer success, while semi-cross-compatible characteristics represent a hindrance. Only 7% of the analyzed embryos were determined to have been fertilized by pollinizers outside the orchard, confirming the significance of pollinizer proximity for efficient pollination.

To increase the success rate of the in vitro production (IVP) system of embryos in buffalo, it is necessary to improve parameters. This field requires more research since its results are low compared to cattle. In this study carried out in Colombia, a modification of the methodology to produce buffalo IVP embryos is described, and 24 non-lactating females, aged 4 to 11 years old were included. Follicular wave was synchronised by ablation of the follicles within the ovary, seven days later all follicles were aspirated to obtain oocytes for maturation, fertilisation and embryo production. For all culture media used, animal protein was avoided. Culture media were supplemented with growth factors and other molecules associated with embryonic development. Special care was taken in adding supplements to protect the zygotes against the harmful effect of oxygen free radicals in the culture medium. Two aspiration series were performed 15 days apart. The average number of oocytes obtained by aspiration was 11.33, the number of blastocysts was 3.05, and the obtained blastocyst production rate (36.2%) was higher than literature reports for this species; we hypothesise that this increase is associated with the supplements added. It was possible to observe a female that produced 50 oocytes. Subsequent research is needed to evaluate the effect of the medium on embryo quality and pregnancy rates. A cost analysis of the new proposed medium is required, since all supplements must be imported and handled with a cold chain of up to -80oC, making it more expensive and restricting widespread use. Finally, it is shown that with three embryos per aspiration, at least one pregnancy can be successful after the aspiration, which is one of the objectives of the IVP system., Za povećanje djelotvornosti sustava in vitro proizvodnje (IVP) zametaka u bizona, potrebno je poboljšati parametre. Budući da su rezultati slabi u usporedbi s govedima slavi ovo područje zahtijeva više istraživanja. U ovom radu, provedenom u Kolumbiji, modifikacija metodologije za proizvodnju IVP zametaka bizona opisana je na sljedeći način: korištene su 24 ženke u dobi između 4 i 11 godina, a koje nisu bile u laktaciji. Folikularni val je sinkroniziran ablacijom folikula unutar jajnika, a nakon sedam dana obavljena je aspiracija svih folikula ženki za dobivanje oocista za dozrijevanje, oplodnju i proizvodnju embrija. Za sve rabljene podloge izbjegavan je životinjski protein. Podloge su obogaćene faktorima rasta i drugim molekulama povezanima s razvojem embrija. Posebna pozornost posvećena je pri dodavanju dodataka za zaštitu zigota od štetnih učinaka slobodnih radikala u podlozi. Obavljene su dvije aspiracijske serije u razmaku od 15 dana. Prosječni je broj oocista dobivenih aspiracijom bio 11,33, broj blastocista bio je 3,05, a dobivena je stopa proizvodnje blastocista (36,2 %) bolja je u usporedbi s onom koju su objavili drugi autori u državi, za istu vrstu. Pretpostavljamo da je ovo povećanje povezano s dodanim dodatcima, bilo je moguće promatrati ženku koja je proizvela 50 oocista. Naknadno je istraživanje potrebno za procjenu učinka podloge na kvalitetu zametaka i postotka gravidnosti; potrebna je i analiza troškova novog predloženog medija, jer se svi dodatci moraju uvesti u Kolumbiju i čuvati u hladnim uvjetima do minus 80 oC, što ih čini skupljima, a ograničava i njihovu široku primjenu. Na kraju našeg istraživanja uočeno je da s tri zametka po aspiraciji u ove vrste nije teško postići najmanje jednu gravidnost, a to je i jedan od ciljeva IVP-a.

The study was developed at the Pampa del Arco Experimental Center of the National University of San Cristóbal de Huamanga, the objective was to evaluate doses of 800 IU (T1) and doses of 1000 IU (T2) of eCG to obtain embryos. Eight adult female llamas were used, distributed four in each treatment (T1 and T2), with a body condition of 2.5, these were evaluated by ultrasound with a 7.5 MHz rectal linear transducer. Hormonal treatments began when the animals had a follicle> 7 mm. The application of eCG was 72 hours after the induction of ovulation of the dominant follicle with GnRH, on day 7 PGF2α was applied, natural mounting was performed plus GnRH (1ml), on day 15 the collection and evaluation of embryos was performed. The results obtained were the pre-ovarian stimulation follicular diameter of 8.3 mm and 9.1 mm for T1 and T2 respectively, the number of pre-ovulatory follicles was 6.33 and 5.50 for T1 and T2 respectively, the diameter of follicles pre-ovulatory was 11.2mm and 10.6 mm for T1 and T2 respectively, average of embryos recovered per donor was 4.66 ± 0.81 and 3.50 ± 0.54 embryos for T1 and T2 respectively, with a significant difference (p

Aquaporins (AQPs) are proteins with various functions related to proper cell function and early development in mammals. The aim of this study was to evaluate the presence of AQPs and determine their mRNA levels in the cumulus oocyte complex (COC) of four bovine breeds and in blastocysts of five bovine crosses. Grade I, II and III COCs were collected by ovum pick up from non-lactating heifers of the Brahaman, Holstein, Gir and Romosinuano breeds. Embryos were produced in vitro up to the blastocyst stage of the bovine ♀Gir × ♂Holstein, ♀Holstein × ♂Gir, ♀Brahman × ♂Holstein, ♀Holstein × ♂Brahman, and ♀Romosinuano × ♂Holstein crosses. mRNA expression of AQP1-AQP12b was estimated in COC and embryos by real-time-PCR. The presence of the twelve AQPs in the COCs and bovine embryos was established. Additionally, significant differences were determined in the expression of AQP6 and AQP12b in COCs, as well as in transcripts levels of AQP4, AQP8 and AQP9 from bovine embryos. Gene expression of AQPs in COCs and bovine embryos is consistent with the previously described biological functions. This is the first report of AQPs in COC of Gir, Brahman, Holstein and Romosinuano and embryos of five crossbreeds between Bos indicus and B. taurus.

The rising concerns about controversial food additives’ potential hazardous properties require extensive yet animal-minimized testing strategies. Zebrafish embryos are the ideal in vivo model representing both human and environmental health. In this study, we exposed zebrafish embryos to eight controversial food additives. Our results indicate that Sodium Benzoate is a Cat.3 aquatic toxicant, while Quinoline Yellow is a strong teratogen. At high concentrations, non-toxic chemicals induced similar phenotypes, suggesting the impact of ionic strength and the applicability of the darkened yolk phenotype as an indicator of nephrotoxicity. Three food additives showed unpredicted bioactivities on the zebrafish embryos: Brilliant Blue could weaken the embryonic yolk, Quinoline Yellow may interfere with nutrient metabolism, and Azorubine induced precocious zebrafish hatching. In conclusion, the zebrafish embryo is ideal for high throughput chemical safety and toxicity screening, allowing systematic detection of biological effects—especially those unexpected by targeted in vitro and in silico models. Additionally, our data suggest the need to reconsider the safety status of food additives Quinoline Yellow, Brilliant Blue, Sodium Benzoate, and other controversial food additives in further studies, as well as pave the way to further applications based on the newly found properties of Brilliant Blue and Azorubine.

Recurrent miscarriage is classically defined as three or more consecutive pregnancy losses in about 1–5% of couples trying to conceive. However, several researchers have amended this to two or more because of the recent increase in childless miscarriages. Recurrent miscarriage is a clinical challenge for clinicians because there are many possible causes, and diagnostic testing is expensive and time-consuming. Established causes of recurrent miscarriage are antiphospholipid antibodies, uterine anomalies, and abnormal chromosomes in either partner, particularly translocations. Uterine anatomical abnormalities, endocrine abnormalities, infections, immunologic factors, environmental factors, metabolic or hormonal disorders, sperm quality, and maternal and paternal age have each been linked. Among them, the genetic factor plays a significant role in recurrent miscarriage. Approximately 70% of miscarriage conceptions with sporadic spontaneous miscarriage reveal some chromosome abnormality. Specifically, recurrent miscarriage can be caused by a structural or numerical defect in the parents' or fetus' chromosomes. Recurrent miscarriage has been linked to several genes, including those involved in oxidative stress, angiogenesis, clotting, and inflammation. Despite several well-known etiologic factors, the etiology of recurrent miscarriage is unknown in over half of all instances. The current review aims to analyse the role of the genetic basis of recurrent miscarriages.

Objective This study aims to investigate the status of fertility preservation (FP) in young breast cancer patients. Materials and methods A clinical database of six women with breast cancer who wished to undergo FP before starting chemotherapy were analyzed between January 2018 and December 2019 in our hospital. Among the six women, three were unmarried and three were married. Results Three patients chose oocyte preservation and obtained 23, 7, and 17 MII oocytes, respectively. One patient chose embryo freezing, and three embryos were frozen. Fertility preservation failed for two patients, one of whom had premature ovulation, while the other patient abandoned egg retrieval on the human chorionic gonadotropin (HCG) day. Conclusion The present results indicate that oocyte and embryo cryopreservation are effective optional methods for young breast cancer patients. However, a lack of knowledge, the urgency of cancer treatment, and financial constraints are causes for a low access rate regarding this process.

Will I be my corpse someday? This is a controversial philosophical question. If I’m a material being, that question is an important part of the metaphysics of material beings. Animalism claims that I’m a human animal. I have started as a fetus. Eric Olson argued that this is incompatible with the psychological-continuity approach to personal identity. From this it follows that we should accept the biological approach; the persistence condition for me is a Life. William Carter suggested that this approach has the same problem with the corpses as the psychologicalcontinuity approach has with fetuses. I’m going to show that Carter is not right, but we should slightly specify a biological approach: the persistence condition for me is my Life

The present study aims to evaluate the effect of two culture media on the production of in vitro embryos in alpacas (Vicugna pacos). The ovaries were transported at 10.52° C in 0.9% saline solution supplemented with gentamicin. The ovaries were transported at 10.52° C in 0.9% physiological saline solution supplemented with gentamicin. 492 ovaries were used throughout the experiment. 2142 oocytes of quality I, II and III were recovered. The oocytes were matured in vitro for 32 h and were subsequently fertilized (incubated for 18 h) with sperm obtained from the tail of the epididymis and selected with a 45/90 percoll gradient. Then, the presumed zygotes were denuded from the cumulus cells, to later be cultured in two culture media: synthetic oviductal fluid medium (SOFaa) and simple optimized potassium medium (KSOMaa) and incubated at 38.5 ° C, 5 % CO2, 5%, O2, and 90% relative humidity for 7 days. Morula and blastocyst rate evaluation was performed at the end of embryo culture. The morula rate at 7 days was 41.49 ± 10.52 and 41.51 ± 6.50% for KSOMaa and SOFaa, respectively (P

Potamotrygon magdalenae, una raya perteneciente a la familia Potamotrygonidae distribuida en la cuenca del río Magdalena, es considerada de muy alta prioridad para la investigación en el Plan de Acción Nacional para la Conservación y Manejo de Tiburones, Rayas y Quimeras de Colombia. Los estudios de desarrollo embrionario en condrictios son escasos debido a la dificultad para obtener el material biológico y son pocas las tablas de desarrollo para las especies de rayas. En este estudio se hizo la caracterización morfológica macroscópica de una serie de estadios embrionarios de P. magdalenae. Se obtuvieron 30 individuos entre embriones, fetos y neonatos producto de disecciones y abortos de hembras grávidas capturadas mediante pesca incidental. En términos generales, el desarrollo embrionario de esta especie sigue los patrones conocidos para los demás condrictios, aunque con pequeñas diferencias en la tasa de absorción del saco vitelino y la ausencia de filamentos branquiales sobresalientes de los espiráculos, lo que puede relacionarse con su viviparidad y matrotofia uterina. Potamotrygon magdalenae is a stingray belonging to the family Potamotrygonidae distributed in the Magdalena River basin. This species is considered of high priority for research according to the National Plan of Action for the Conservation and Management of Sharks, Rays, and Chimaeras of Colombia. The studies of embryonic development in chondrichthyans are limited due to the difficulty in obtaining the biological material and there are few developmental staging tables for ray species. Here we do a macroscopic morphological characterization of a series of developmental stages of P. magdalenae. Thirty individuals were studied, including embryos, fetuses, and neonates resulting from dissections and abortions of pregnant females caught by incidental fishing. It was possible to identify nine stages of development that were described, photographed, drawn, and measured. The embryonic development of this species broadly follows the patterns known for other chondrichthyans with minor differences in the rate of yolk sac absorption and the absence of protruding gill filaments from the spiracles, which may be related to its viviparity and intrauterine matrotrophy.

Supplementation of the culture media for in vitro production (IVP) of bovine embryos with fetal bovine serum (FBS) is associated with inconsistent outcomes. The present study sought to replace FBS and BSA by insulin-like growth factor 1 (IGF1), fibroblast growth factor 2 (FGF2) and epidermal growth factor (EGF). In Experiment 1, absence of FBS from maturation medium (MM) did not affect the rate of in vitro maturation, as assessed by the extrusion of the first polar body. However, when gonadotropins and FBS were removed from the MM, the maturation rate was significantly reduced even in the presence of growth factors. Therefore, gonadotropin-supplemented MM medium was established as the base medium for the defined maturation condition. In Experiment 2, the addition of growth factors to gonadotropin-supplemented MM medium supported similar maturation (~90%) compared to the undefined condition (FBS-carrying). In Experiment 3, the addition of growth factors to embryo culture medium showed similar in vitro competence compared to the undefined (FBS) control. In Experiment 4, completely defined conditions (absence of FBS and BSA during in vitro maturation and embryo culture) were tested. A higher cleavage was observed with FGF2 (86%) compared to EGF (77%) and the FBS control (77%), but similar blastocyst rates were observed for FGF2 (24%), EGF (19%) and the FBS control (25%). Embryo quality was similar among groups. Finally, post-thawing survival was higher for FGF2 (94%) compared to the FBS control (77%). Thus, we report a simple defined IVP system for bovine species that generates developmental outcomes and embryos of similar quality than those produced under conditions containing FBS.

To date, drugs released into the aquatic environment are a real problem, and among antibiotics, sulfamethoxazole is the one most widely found in wastewater; thus, the evaluation of its toxicity on marine organisms is very important. This study, for the first time, investigates the in vitro effects of 4 concentrations of sulfamethoxazole (0.05 mg/L, 0.5 mg/L, 5 mg/L, 50 mg/L) on the fertilization and development of the sea urchin Arbacia lixula. The gametes were exposed to drugs in three different stages: simultaneously with, prior to, and post-fertilization. The results show a significant reduction in the percentage of fertilized oocytes at the highest drug concentrations. Moreover, an increase in anomalies and delays in embryo development following the treatment with the drug was demonstrated. Therefore, the data suggest that this antibiotic can alter the development of marine organisms, making it urgent to act to reduce their release and to determine the concentration range with the greatest impact.

tablas Una de las biotecnologías que ha tenido mayor impacto en la eficiencia productiva de los hatos es la producción in vitro de embriones bovinos. Sin embargo, se han encontrado falencias en los componentes utilizados en la preparación de medios en los laboratorios como el suero fetal bovino (SFB), que aunque aumenta la producción de embriones, genera dificultades en la criopreservación de embriones debido a la acumulación de lípidos en el citoplasma. De acuerdo con lo anterior, en el presente trabajo se usó la Sericina, una proteína extraída del gusano de seda, como alternativa al SFB. Así mismo, se conoce que el estrés oxidativo genera la alteración del ovocito y las células embrionarias en condiciones in vitro, por lo tanto, en esta investigación se empleó el isoespintanol, un antioxidante natural con gran capacidad de neutralización de las especies reactivas de oxígeno, con la finalidad de mejorar el proceso de producción in vitro de embriones bovinos y su tolerancia a la criopreservación. Se aspiraron ovocitos de folículos con tamaño de 3 a 8 mm de ovarios de hembras faenadas. Se seleccionaron los ovocitos viables de calidad 1 y 2, se pusieron en gotas de 100 ul de medio de maduración y se dejaron durante 22 a 24 horas en condiciones de 38.5°C y 5% de CO2. Se hicieron tres experimentos distribuidos de la siguiente manera: Primero se realizó la maduración in vitro (MIV) de los ovocitos con cuatro concentraciones de sericina, 0.1%, 0.5%, 1.0% y 2.5%. Se incluyó un tratamiento control con SFB y luego se seleccionaron las dos concentraciones con mayores tasas de MIV. Para el isoespintanol se evaluaron tres concentraciones hasta la expulsión del primer cuerpo polar: 10 µM, 20 µM y 30 µM. Para el segundo experimento, se seleccionaron las dos concentraciones con mejores resultados, que fueron 0.5% y 1.0%, para la sericina y 10 µM y 20 µM para el isoespintanol. Se realizó la MIV bajo seis tratamientos: T1 (10 % SFB) - control 1, T2 (Sin fuente de proteína) - control 2, T3 (sericina 0,5%), T4 (sericina 1%), T5 (isoespintanol 10 µM más 10% SFB), y T6 (isoespintanol 20 uM más 10% SFB). Después de 24 horas se realizó la fecundación in vitro durante 18–20 horas, se llevó a cabo la eliminación de las células del cúmulus y finalmente, los posibles cigotos se colocaron en medio de cultivo hasta etapa de blastocistos al día 7. Se obtuvo respuesta positiva en el reemplazo completo del SFB como fuente de proteína en los medios de maduración, obteniéndose mejores resultados con sericina al 1% e isoespintanol con 20 µM. Para el tercer experimento, se utilizó la misma combinación de las dos concentraciones de sericina e isoespintanol seleccionadas hasta etapa de blastocistos al día 7. Se establecieron tres tratamientos en la MIV: T1 (10% SFB) - control 1, T2 (sin fuente de proteína) - control 2 y T3 (1% de sericina más 20 µM de isoespintanol). En este último experimento, se encontró que la combinación de ambos componentes no arrojó resultados superiores con respecto a los tratamientos controles. Este trabajo concluye que la sericina podría usarse como fuente de proteína durante la MIV de los ovocitos bovinos, en reemplazo del suero fetal bovino. Así mismo, el isoespintanol puede utilizarse como suplemento antioxidante en los medios de maduración para la producción in vitro de embriones bovinos. (Texto tomado de la fuente) One of the biotechnologies having the greatest impact on the productive efficiency of herds is the in vitro production of bovine embryos. However, shortcomings have been found in the components utilized in the preparation of media in laboratories such as bovine fetal serum (BFS), which, although it increases the production of embryos, it also generates difficulties in the cryopreservation of the embryos due to the accumulation of lipids in the cytoplasm. Considering that, this analysis uses Sericin, a protein extracted from silkworms, as an alternative to BFS. It has been known that oxidative stress generates an alteration to the oocyte and embryonic cells under in vitro conditions, therefore, this research uses isospintanol, a natural antioxidant with a the capacity to neutralize oxygen reactive species, in order to improve the in vitro production process of bovine embryos and its tolerance to cryopreservation. Oocytes from follicles with a size of 3 to 8 mm were extracted from ovaries of slaughtered females. Eligible oocytes with quality 1 and 2 were selected, placed in 100 ul drops of a maturation medium and left for 22 to 24 hours under conditions of 38.5°C and 5% CO2. Three experiments were completed as follows: First, in vitro maturation (“IVM”) of the oocytes was performed with four different concentrations of sericin, 0.1%, 0.5%, 1.0% and 2.5% and a BFS control treatment, then the two concentrations with the highest IVM rates were selected. For isospintanol, three concentrations were evaluated to the expulsion of the first polar body, 0 µM (Control), 10 µM, 20 µM and 30 µM. For the second experiment, the two concentrations with the best IVM results were selected, 0.5% and 1.0% for sericin and 10 µM and 20 µM for isospintanol. The IVM was performed under six treatments: T1 (10% BFS) – control 1, T2 (without protein source) – control 2, T3 (0.5% sericin), T4 (1% sericin), T5 (10 µM isospintanol plus 10% BFS), and T6 (20 uM isospintanol plus 10% BFS). After 24 hours of IVM, in vitro fertilization was performed for 18-20 hours, the cumulus cells were eliminated and finally, the possible zygotes were placed in a culture medium until day seven. A positive result was obtained in the complete replacement of BFS as a protein source in the maturation media, obtaining better results with 1% sericin and 20 µM isospintanol. For the third experiment, the same two concentrations of sericin and isospintanol were used to the blastocyst stage on day seven. Three IVM treatments were performed: T1 (10% FBS) – control 1, T2 (without protein source) - control 2, and T3 (1% sericin plus 20 µM isospintanol). In this last experiment, it was found that the combination of both components did not yield superior results with respect to the control treatments. This work concludes that sericin could be used as a protein source during IVM of bovine oocytes, in replacement of bovine fetal serum. It also concludes that isospintanol can be used as an antioxidant supplement in maturation media for the in vitro production of bovine embryos. Politécnico Colombiano Jaime Isaza Cadavid Maestría Magister en Ciencias - Biotecnología Reproducción Animal Área Curricular Biotecnología

The article discusses the features of eggs, the confinement of oviposition to certain stages of embryonic development, and its adaptive significance in some oviparous reptile species in Azerbaijan. Information is reported on the size and numbers of eggs in clutches, stages of development of embryos at the time of oviposition, as well as the timing of natural incubation of eggs in the Mediterranean tortoise (Testudo graeca ibera) and the Levantine viper (Macrovipera lebetina obtusa), including providing information on the size and number of eggs in clutches, as well as the relationship between the number of eggs in clutches and their size and weight. It has been experimentally proven that it is by the day of oviposition that embryos acquire the greatest resistance to temperature factors of the external environment. The embryos are most protected in eggs of a turtle with a hard shell (Testudo graeca), eggs are laid in the early stages of embryonic development (beginning and middle of gastrulation). However, in the Levantine viper (Macrovipera lebetina obtusa), the eggs are covered only with a fibrous membrane and the laying of eggs occurs at later stages of embryonic development (the stage of laying the tongue). It was also identified that in both species the ranges of morphological variability of embryos at the time of oviposition, in populations living at different heights, are the same. The tactical variability in the reproduction of oviparous reptiles is thought to be a result of their evolutionary adaptation to land reproduction. The incubation of eggs in the external environment lasted 80-85 days in the tortoise and 50-55 days in the viper. This is because in turtles, eggs are laid earlier, and in the Levantine viper at later stages of embryo development. In the Levantine viper, a significant part of the development of the embryos (30-35 days) occurs while the eggs are in the oviducts of the female.

Mercury (Hg), as the most potentially hazardous heavy metal, has accumulated in the aquatic environment and has caused concern about its safety. To test the toxic effects of mercury chloride (Hg2+) on rare minnow (Gobiocypris rarus), the acute toxicity of Hg2+ to embryos, newly hatched larvae, juvenile fish, and the short-term developmental toxicity of Hg2+ to the embryo and sac-fry stages, were investigated. The 96-h LC50 values of Hg2+ to embryos, newly hatched larvae, and juvenile fish were 0.56, 0.07, and 0.10 mg/L, respectively, suggesting newly hatched larvae were the most sensitive, followed by juvenile fish, while embryos were the most resistant in response to an Hg2+ challenge. The research data revealed that the safe level of Hg2+ exposure for rare minnow was 0.7 μg/L. In addition, the LOEC (lowest observed effect concentration) and NOEC (no observed effect concentration) values of Hg2+ to heartbeat, mortality, malformation rate, and body length of survived larvae were identically, 0.05 and 0.01 mg/L, respectively. These findings indicated that Hg2+ had lethal effects on rare minnow at different life stages, and that newly hatched larvae were the most sensitive stage. The above findings have important implications for better understanding the environmental risk assessment of Hg2+ on aquatic organisms.

Amer Mahmoud Sindiani,1 Faheem Zayed,2 Eman Hussein Alshdaifat,3 Hasan M Rawashdeh,1 Wesam Al-Woshah,4 Nada Zayed5 1Department of Obstetrics and Gynecology, Faculty of Medicine, Jordan University of Science and Technology, Irbid, Jordan; 2Department of Obstetrics and Gynecology, Irbid Speciality Hospital, Irbid, Jordan; 3Department of Obstetrics and Gynecology, Yarmouk University, Irbid, Jordan; 4Department of Obstetrics and Gynecology, IBN Al-Nafis Hospital, Irbid, Jordan; 5Department of Dermatology, Albalqa Applied University, Salt, JordanCorrespondence: Amer Mahmoud SindianiDepartment of Obstetrics and Gynecology, Faculty of Medicine, Jordan University of Science and Technology, PO Box: 3030, Irbid, 22110, JordanTel +962796025538Email amsindiani0@just.edu.joPurpose: To find out whether couples with predominant female offspring have more chances to produce more female embryos during non-medical pre-implantation genetic diagnosis (PGD) for male sex selection.Methods: A total of 125 couples who had three or more female offspring and underwent non-medical PGD for male sex selection between 2015 and 2019 were included. Nuclear DNA was analyzed by fluorescent in situ hybridization (FISH). Two-chromosome (X, Y), 3-chromosome (21, X, Y), and 5-chromosome (13, 18, 21, X, Y) probes were used for FISH. The standard protocol was followed for sperm processing and embryo culture for IVF and PGD.Results: In 83.2% of the couples, the ratio of female embryos was higher than male embryos. Independent sample t-test showed that there is no significant difference between equal and unequal embryonic groups in patients’ age, husbands’ age, sperm count, sperm motility, total male embryos, total female embryos, normal male embryos, and normal female embryos. For patients with positive pregnancy outcome, 84.6% had unequal embryonic ratio while 15.4% had equal embryonic ratio. Similarly, patients who were treated by short protocol had 85% of unequal embryonic ratio and 15% had equal ratio.Conclusion: A greater variability in the female to male embryonic ratio is produced in couples having predominantly female offspring and seeking non-medical PGD for male sex selection.Keywords: embryos, infertility, IVF, PGD

Chromium (Cr) is an element present in nature in mineral form. It has a dual effect, both as an essential micronutrient and a carcinogenic agent depending on its chemical form and concentration. It is present in various environmental matrices such as water, soil, and air, coming from natural and anthropogenic sources, and causes harmful effects on biota, ecosystems, and even human beings. This study's objective was to evaluate chromium toxicity and teratogenicity in zebrafish embryos of Danio rerio exposed to chromium through the D. rerio teratology assay ( Dar TA) test by evaluating spine malformations. To this end, the chromium toxicity curve was calculated from zebrafish embryos exposed to potassium dichromate (K 2 Cr 2 O 7 ), and the probit test was used to establish the mean lethal concentration (LC50) and three subtoxic concentrations LC 25 , LC 12.5 , and LC 6.25 to evaluate the teratogenicity. The results showed that potassium dichromate was statistically positive for the teratogenic effect at the three highest concentrations evaluated. Potassium dichromate exposure causes abnormal embryonic development and teratogenic effects, including severe heart defects in zebrafish embryos. Therefore, we conclude that potassium dichromate is toxic to the zebrafish developmental stages. The finding that potassium dichromate is teratogenic in zebrafish embryos suggests that this metal should be tested and evaluate potential risk in mammalian systems.

Scientific reports 11(1), 10160 (2021). doi:10.1038/s41598-021-89566-w, Published by Macmillan Publishers Limited, part of Springer Nature, [London]

Data of this study are about the effects of transgenerational effects of thermal stress on morphometric data (eye diameter, arm length, mantle length, yolk, length, egg length egg wide and wet weight), routine oxygen consumption, oxidant damage (Protein oxidation; PO), antioxidant defense mechanisms (Catalase, glutathione-s-transferase, total glutathione)and esterases (carboxyl esterase and acetylcholinesterase) of embryos spawned by females exposed at 24 and 30°C until spawn. Embryos of both groups of femaleswere spread in two groups: one incubated at 24 and the other at 30°C. Evaluations were grouped in threeembryo stages: organogenesis, activation, and growth.&nbsp

Nanomateriali (NM) so večnamenske snovi, ki se uporabljajo v skoraj vseh industrijskih panogah in kategorijah izdelkov. Titanov dioksid (TiO2) je eden najbolj vsestransko uporabnih NM, ki se uporablja kot pigment za barvila, v hrani in kozmetičnih izdelkih. Kot aditiv v prehranskih izdelkih se uporablja TiO2 z oznako E171. Namen magistrske naloge je bil proučiti potencialne negativne učinke TiO2 E171 (anataz, premer 100 ̶ 200 nm) na razvoj zarodkov rib cebric (Danio rerio). Zarodke na stopnji blastule smo za 48 ur izpostavili različnim koncentracijam TiO2 (1 mg/l, 10 mg/l in 100 mg/l) in spremljali razvoj do izleganja (72 ur). Zarodke smo pregledovali v 24 urnih intervalih in preverjali letalne (koagulacija zarodkov, utrip srca, mišična kontrakcija in rep nesporščen od RV) in subletalne učinke (izleganje, dolžino ličink in razvojne nepravilnosti). Pri najvišji koncentraciji TiO2 je bila smrtnost 15 %, letalni učinki so se izražali predvsem kot koagulacija zarodkov, ki je bila intenzivnejša v prvih 24 urah razvoja. Izkazalo se je, da TiO2 spodbuja zgodnje izleganje zarodkov iz horionskega ovoja. Po 48 urah razvoja je bilo 16 ̶ 24 % zarodkov izleženih, z najvišjim deležem pri najvišji koncentraciji TiO2. Učinek na dolžino telesa je bil zanemarljiv. Vsaj eno razvojno nepravilnost je imelo od 13% do 29% zarodkov, kar je bilo odvisno tudi od izpostavitvene koncentracije. Rezultati naše raziskave kažejo, da je pri oceni toksičnosti potrebno upoštevati tudi subletalne učinke in spremljati razvojne nepravilnosti, saj bi v nasprotnem primeru toksičnost nanodelcev lahko podcenili. Nanomaterials (NMs) are multipurpose substances used in almost all industries and product categories. Titanium dioxide (TiO2) is one of the most versatile NMs, especially E171, which is used as an additive in food products. The aim of this master's thesis was to investigate its potential negative effects on zebrafish (Danio rerio) embryo development. Blastula stage embryos were exposed to different concentrations of TiO2 E171 (1 mg/l, 10 mg/l and 100 mg/l) for 48 hours and development was monitored until hatching (72 hours). Embryos were examined at 24-hour intervals and assessed for lethal (embryo coagulation, heart rate, muscle contraction, and detachment of the tail from the RV) and sublethal effects (hatching and developmental abnormalities). At the highest TiO2 concentration, mortality was 15 %, and lethal effects were mainly manifested in embryo coagulation, which was more pronounced in the first 24 hours of development. TiO2 promoted early hatching of embryos from the chorionic membrane by 16 ̶ 24 % after 48 hours of development, while the effect on body length was negligible. At the highest TiO2 concentration, at least one developmental abnormality occurred in 29 % of embryos. The results of our research suggest that sublethal effects should be considered and developmental abnormalities should be monitored when assessing toxicity, otherwise the toxicity of nanoparticles may be underestimated.

The mechanism of symbiont-induced cytoplasmic incompatibility (CI) has been a long-standing mystery. A new study on Wolbachia's Cif proteins in PLOS Biology provides supportive evidence for the "Host modification model, " although the alternative "Toxin-antidote model" is still in the running.

We previously developed a new vitrification method (equilibrium vitrification) by which two-cell mouse embryos can be vitrified in liquid nitrogen in a highly dehydrated/concentrated state using low concentrations of cryoprotectants. In the present study, we examined whether this method is effective for mouse embryos at multiple developmental stages. Four-cell embryos, eight-cell embryos, morulae, and blastocysts were vitrified with EDFS10/10a, 10% (v/v) ethylene glycol and 10% (v/v) DMSO in FSa solution. The FSa solution was PB1 medium containing 30% (w/v) Ficoll PM-70 plus 0.5 M sucrose. The state of dehydration/concentration was assessed by examining the survival of vitrified embryos after storage at -80°C. When four-cell embryos and eight-cell embryos were vitrified with EDFS10/10a in liquid nitrogen and then stored at -80°C, the survival rate was high, even after 28 days, with relatively high developmental ability. On the other hand, the survival of morulae and blastocysts vitrified in liquid nitrogen and stored at -80°C for four days was low. Therefore, morulae and blastocysts cannot be vitrified in a highly dehydrated/concentrated state using the same method as with two-cell embryos. However, when blastocysts were shrunken artificially before vitrification, survival was high after storage at -80°C for four days with high developmental ability. In conclusion, the equilibrium vitrification method using low concentrations of cryoprotectants, which is effective for two-cell mouse embryos, is also useful for embryos at multiple stages. This method enables the convenient transportation of vitrified embryos using dry ice.

An anlage of the superior and inferior mesenteric arteries has been revealed in 19 series of consecutive histological sections of human embryos by means of the methods of the microscopy, graphic and plastic reconstruction and morphometry. The omphalo-mesenteric artery is the largest unpaired visceral branch of the aorta., Методами микроскопии, графической и пластической реконструкции, морфометрии 19 серий последовательных гистологических срезов зародышей человека выявлено закладку верхней и нижней брыжеечных артерий. Наиболее крупной ветвью непарной брюшной аорты есть желточно-брыжеечная артерия., Методами мікроскопії, графічного і пластичного реконструювання та морфометрії 19 серій послідовних гістологічних зрізів зародків людини виявлено закладку верхньої та нижньої брижових артерій. Найбільшою непарною вісцеральною гілкою аорти є жовтково-брижова артерія.

In vitro embryo production (IVP) is a biotechnology applied to different species of domestic and wild mammals, in addition to humans. IVP includes the in vitro maturation of oocytes (IVM), in vitro fertilization of matured oocytes (IVF) and the in vitro culture of fertilized oocytes (IVC). In the IVM and IVC processes there is an increase in levels of reactive oxygen species (ROS) that generate higher levels of oxidative stress, which together with a deficient antioxidant system in in vitro conditions can affect these processes. Faced with this situation, the maturation media are supplemented with antioxidant compounds such as cysteamine (CYS), which is an amino thiol (SCH2CH2NH) of low molecular weight (77.1 g/mol), has its own antioxidant activity, promotes the transport of cysteine to the interior of the cell and favours the synthesis of glutathione (GSH). Research on the use of CYS in IVP indicates that it stimulates GSH production, oocyte maturation and favours the segmentation and blastulation process. In addition, it has synergistic effects with other antioxidants or with growth factors, so the interest in this molecule and its effects on IVP has increased over the years. This review article presents the properties and effects of cysteamine in the in vitro production system of embryos in ruminants., La producción in vitro de embriones (PIVE) es una biotecnología aplicada a diferentes especies de mamíferos domésticos y silvestres, además del humano. La PIVE comprende la maduración in vitro de ovocitos (MIV), fecundación in vitro de ovocitos madurados (FIV) y el cultivo in vitro de ovocitos fertilizados (CIV). En los procesos de la MIV y CIV se tiene un incremento de los niveles de especies reactivas del oxígeno (ROS) que generan mayores niveles de estrés oxidativo, que ante junto a un deficiente sistema antioxidante en condiciones in vitro se pueden afectar estos procesos. Ante esta situación, los medios de maduración se suplementan con compuestos antioxidantes como la cisteamina (CYS) que es un amino tiol (HSCH2CH2NH) de bajo peso molecular (77.1 g/mol), tiene actividad antioxidante propia, promueve el transporte de cisteína al interior de la célula y favorece la síntesis de glutatión (GSH). Investigaciones sobre el uso de la CYS en la PIVE indican que se estimula la producción de GSH, la maduración ovocitaria y favorece el proceso de segmentación y blastulación; asimismo, tiene efectos sinérgicos con otros antioxidantes o con factores de crecimiento, de manera que el interés sobre esta molécula y sus efectos en la PIVE ha ido aumentando a través de los años. Este artículo de revisión presenta las propiedades y efectos de la cisteamina en el sistema de producción in vitro de embriones en rumiantes.

Precise regulation of gene expression ensures oocytes and embryos accomplish the dynamic events required for successful oocyte maturation and early embryo development. However, most studies of gene expression regulation have focused on the mouse. In this respect, we used the cow as an alternative mammalian model to study gene expression regulation during oocyte maturation and early embryo development. We described dynamic changes in gene expression and poly(A) tail length during bovine oocyte maturation and early embryo development. As a result of these changes, the reference genes most suitable for gene expression normalization are different when different reverse transcription priming methods are employed. On the other hand, epigenetic alterations and differential regulation of transcription factors affect gene expression at the transcriptional level in embryos. One of the major epigenetic events-XCI, is initiated at morula stage in female bovine embryos. However, the initiation of XCI does not lead to complete down-regulation of all X-linked genes. The expression of the transcription factor CDX2 in bovine embryos is up regulated after exposure to LPA. But LPA stimulation does not change embryo constitution in terms of percentages of cells committed to one or another lineage. Overall, a better understanding of gene expression regulation during ocoyte maturation and early embryo development broadens our fundamental knowledge of mammalian embryonic development and will improve our understanding of the requirements for cell lineage determination and pluripotency, and the short and longer term consequences of epigenetic disturbances resulting from sub-optimal maternal health and nutrition or in vitro fertilization and embryo culture conditions.

Precise regulation of gene expression ensures oocytes and embryos accomplish the dynamic events required for successful oocyte maturation and early embryo development. However, most studies of gene expression regulation have focused on the mouse. In this respect, we used the cow as an alternative mammalian model to study gene expression regulation during oocyte maturation and early embryo development. We described dynamic changes in gene expression and poly(A) tail length during bovine oocyte maturation and early embryo development. As a result of these changes, the reference genes most suitable for gene expression normalization are different when different reverse transcription priming methods are employed. On the other hand, epigenetic alterations and differential regulation of transcription factors affect gene expression at the transcriptional level in embryos. One of the major epigenetic events-XCI, is initiated at morula stage in female bovine embryos. However, the initiation of XCI does not lead to complete down-regulation of all X-linked genes. The expression of the transcription factor CDX2 in bovine embryos is up regulated after exposure to LPA. But LPA stimulation does not change embryo constitution in terms of percentages of cells committed to one or another lineage. Overall, a better understanding of gene expression regulation during ocoyte maturation and early embryo development broadens our fundamental knowledge of mammalian embryonic development and will improve our understanding of the requirements for cell lineage determination and pluripotency, and the short and longer term consequences of epigenetic disturbances resulting from sub-optimal maternal health and nutrition or in vitro fertilization and embryo culture conditions.

Precise regulation of gene expression ensures oocytes and embryos accomplish the dynamic events required for successful oocyte maturation and early embryo development. However, most studies of gene expression regulation have focused on the mouse. In this respect, we used the cow as an alternative mammalian model to study gene expression regulation during oocyte maturation and early embryo development. We described dynamic changes in gene expression and poly(A) tail length during bovine oocyte maturation and early embryo development. As a result of these changes, the reference genes most suitable for gene expression normalization are different when different reverse transcription priming methods are employed. On the other hand, epigenetic alterations and differential regulation of transcription factors affect gene expression at the transcriptional level in embryos. One of the major epigenetic events-XCI, is initiated at morula stage in female bovine embryos. However, the initiation of XCI does not lead to complete down-regulation of all X-linked genes. The expression of the transcription factor CDX2 in bovine embryos is up regulated after exposure to LPA. But LPA stimulation does not change embryo constitution in terms of percentages of cells committed to one or another lineage. Overall, a better understanding of gene expression regulation during ocoyte maturation and early embryo development broadens our fundamental knowledge of mammalian embryonic development and will improve our understanding of the requirements for cell lineage determination and pluripotency, and the short and longer term consequences of epigenetic disturbances resulting from sub-optimal maternal health and nutrition or in vitro fertilization and embryo culture conditions.

Single-cell whole-genome haplotyping allows simultaneous detection of haplotypes associated with monogenic diseases, chromosome copy-numbering and subsequently, has revealed mosaicism in embryos and embryonic stem cells. Methods, such as karyomapping and haplarithmisis, were deployed as a generic and genome-wide approach for preimplantation genetic testing (PGT) and are replacing traditional PGT methods. While current methods primarily rely on single-nucleotide polymorphism (SNP) array, we envision sequencing-based methods to become more accessible and cost-efficient. Here, we developed a novel sequencing-based methodology to haplotype and copy-number profile single cells. Following DNA amplification, genomic size and complexity is reduced through restriction enzyme digestion and DNA is genotyped through sequencing. This single-cell genotyping-by-sequencing (scGBS) is the input for haplarithmisis, an algorithm we previously developed for SNP array-based single-cell haplotyping. We established technical parameters and developed an analysis pipeline enabling accurate concurrent haplotyping and copy-number profiling of single cells. We demonstrate its value in human blastomere and trophectoderm samples as application for PGT for monogenic disorders. Furthermore, we demonstrate the method to work in other species through analyzing blastomeres of bovine embryos. Our scGBS method opens up the path for single-cell haplotyping of any species with diploid genomes and could make its way into the clinic as a PGT application. ispartof: NUCLEIC ACIDS RESEARCH vol:50 issue:11 ispartof: location:England status: published

Age-related physiological changes are most notable and best-studied late in life, while the nature of aging in early- or middle-aged individuals has not been explored as thoroughly. In C. elegans, many studies of movement vs. age generally focus on three distinct phases: sustained, youthful movement; onset of rapidly progressing impairment; and gross immobility. We investigated whether this first period of early-life adult movement is a sustained “healthy” level of high function followed by a discrete “movement catastrophe”—or whether there are early-life changes in movement that precede future physiological declines. To determine how movement varies during early adult life, we followed isolated individuals throughout life with a previously unachieved combination of duration and temporal resolution. By tracking individuals across the first six days of adulthood, we observed declines in movement starting as early as the first two days of adult life, as well as high interindividual variability in total daily movement. These findings suggest that movement is a highly dynamic behavior early in life, and that factors driving movement decline may begin acting as early as the first day of adulthood. Using simulation studies based on acquired data, we suggest that too-infrequent sampling in common movement assays limits observation of early-adult changes in motility, and we propose feasible strategies and a framework for designing assays with increased sensitivity for early movement declines.

Актуальність. Одним із актуальних напрямів морфологічного дослідження є вивчення особливостей морфогенезу під’язикової кістки у пренатальному періоді онтогенезу людини, так як дані щодо її становлення удосконалять методи оперативних втручань в шийній ділянці та доповнять дані для судово-медичної практики. Мета. З’ясувати особливості розвитку та морфологічних перетворень під’язикової кістки в ранньому періоді онтогенезу людини. Методи. Досліджено 15 препаратів зародків та передплодів людини 12,0-80,0 мм тім’яно-куприкової довжини (ТКД) за допомогою комплексу методів морфологічного дослідження. Результати. У зародків людини 12,0-13,5 мм ТКД зачаток під’язикової кістки візуалізується у вигляді мезенхімальної конденсації в ділянці ІІ глоткової дуги вище рівня шийного синусу. У зародків людини 13,0-13,5 мм ТКД зачаток під’язикової кістки знаходиться на стадії прехондрифікації: каудальний сегмент хряща Рейхарта формує малі роги (похідне ІІ глоткової дуги), а мезодермальна конденсація ІІІ глоткової дуги формує великі роги та тіло. У передплодів 50,0-80,0 мм ТКД під’язикова частина хряща Рейхарта, яка формує малі роги, знаходиться на стадії хондрифікації. Тіло та великі роги під’язикової кістки з’єднані із малими рогами, опускаються нижче рівня зачатка язика та є місцем прикріплення для підпід’язикової групи м’язів шиї. Висновки. 1. Зачаток під’язикової кістки візуалізується наприкінці зародкового періоду розвитку у вигляді мезенхімальної конденсації ІІ та ІІІ глоткових дуг на стадії прехондрифікації. 2. Малі роги під’язикової кістки в передподовому періоді втрачають зв’язок із краніальною частиною хряща Рейхарта. 3. Протягом передплодового періоду розвитку під’язикова кістка знаходиться на стадії хондрифікації та є місцем прикріплення над- та під’язикових м’язів передньої шийної ділянки., Background. Morphogenesis of hyoid bone in early intrauterine development of human is a topical question of anatomical research that is aimed to improve methods of surgical interventions in neck and mandible regions and to supplement data in forensic practice. Objective. To investigate peculiarities of development and morphological transformations of hyoid bone in the early period of human ontogenesis. Methods. 15 specimens of human embryos and prefetuses of 12,0-80,0 mm parietal-coccygeal length (PCL) were investigated by using a set of morphological methods. Results. In human embryos 12,0-13,5 mm PCL, rudiment of hyoid bone is seen as s mesenchymal condensation in second pharyngeal arch area above the level of cervical sinus. In 13,0-13,5 mm PCL embryos, hyoid bone anlage is on prechondrification stage: caudal segment of Reichert’s cartilage forms small horns and mesodermal condensation of III pharyngeal arch forms large horns and body of hyoid. In 50,0-80,0 mm PCL human prefetuses, hyoid part of Reichert’s cartilage, which forms small horns, reaches chondrification stage. The body and large horns of hyoid are connected to small horns, and are found lower the level of tongue anlage. At this stage hyoid bone is an attachment site for the hyoid neck muscles. Conclusions. 1. Rudiment of the hyoid bone is found at the end of embryonic period as a prechondrificational mesenchymal condensation of II and III pharyngeal arches 2. During prefetal period, small horns loose contact with the cranial part of Reichert’s cartilage. 3. Anlage of the hyoid bone during prefetal period is on chondrification stage and is a site of attachment for supra- and infrahyoid muscles., Актуальность. Одним из актуальных направлений морфологического исследования является изучение особенностей закладки и морфогенеза подъязычной кости в пренатальном периоде онтогенеза человека, так как данные о ее становлении усовершенствуют хирургические и дополнят данные для судебно-медицинской практики. Цель. Изучить особенности развития и морфологических изминений подъязычной кости в раннем периоде онтогенеза человека. Методы. Исследовано 15 препаратов зародышей и передплодов человека 12,0-80,0 мм теменно-копчиковой длинны (ТКД) с использование комплекса методов морфологического исследования. Результаты. У зародышей человека 12,0-13,5 мм ТКД закладка подъязычной кости визуализируется в виде мезенхимальной конденсации в области ІІ глоточной дуги выше уровня шейного синуса. У зародышей человека 13,0-13,5 мм ТКД подъязычная кость находится на стадии прехондрификации: каудальный сегмент хряща Рейхарта формирует малые рога (производное ІІ глоточной дуги), а мезодермальная конденсация ІІІ глоточной дуги формирует большие рога и тело. В передплодов 50,0-80,0 мм ТКД подъязычная часть хряща Рейхарта, которая формирует малые рога, находится на стадии хондрификации. Выводы. 1. Зачаток подъязычной кости визуализируется в конце эмбрионального периода развития в виде мезенхимальной конденсации, исходящей из II и III глоточных дуг и находиться на стадии прехондрификации. 2. Малые рога подъязычной кости в передподовом периоде теряют связь с краниальной частью хряща Рейхарта. 3. На передплодовом периоде развития, подъязычная кость находится на стадии хондрификации и является местом прикрепления для над- и подподъязычных мышц шеи.

Ide embryos were incubated in 0.1 mg dm3 of Cu or Cd or in clean tap water (control). Both metals significantly decreased swelling of eggs. They reduced the rate of embryonic development and the hatching rate. Six types of body malformations were found in newly hatched larvae: spine curvature, C-shaped body, head deformation, yolk sac deformation, heart oedema, and reduced body length. Only the first two types of deformations were observed in the control, while more severe malformations were found following Cu and Cd exposure. Copper exerted a detrimental effect mainly during embryogenesis (egg swelling and rate of development), while the toxic effects of cadmium were more significant in newly hatched larvae. Larval body deformities may be used as a bioindicator of water pollution with heavy metals.

Resumen La pandemia por el nuevo virus SARS-CoV-2 ha provocado un proceso de adaptación a la nueva situación por parte de toda de la sociedad y, con ello, los centros de reproducción asistida. Tras la fase aguda de la crisis sanitaria, en la que se redujo de forma drástica la actividad, se han reanudado los ciclos, guiados por las recomendaciones de las sociedades científicas. En este artículo revisamos toda la información publicada respecto al virus y el sistema reproductivo, señalando la presencia de enzima convertidora de angiotensina tipo ii(angiotensin-converting enzyme 2, ACE2) en el sistema reproductivo femenino y masculino, a nivel testicular, ovárico, endometrial y a nivel embrionario. Además, realizamos un análisis comparativo entre las recomendaciones de las sociedades científicas en cuanto al cribado de la infección, las normas de funcionamiento y las medidas generales de laboratorio.

We investigated the effects of short-term exposure of bare TiO2NPs and polyelectrolyte-coated TiO2NPs in the 5–25 nm size range, at relatively high concentrations (of 500 and 1000 mg/L) under light or dark conditions, in D. rerio embryos. The biological endpoints investigated included embryo viability and mRNA transcript levels of antioxidant and membrane transport genes relative to control embryos. The presence of nanoparticles on the surface of embryos was assessed using TEM. The results confirm an accumulation of TiO2NPs on the outer surface (chorion) of the embryo, but not within the embryo. No significant difference in embryo viability was detected following each exposure regime. The expression of antioxidant biomarker, SOD2, was significantly impacted by the type of TiO2NP, with TiO2NPs/PSS/PAH coating exposure showing down regulation; the concentration of the nanoparticles, with down regulation at 500 mg/L; and dark/light condition with down regulation in the light. The expression levels of the hypoxia and membrane markers, HIF1 and Pxmp2, were not significantly impacted by any factor. The study indicates that SOD2 mRNA expression levels may be useful in the detection of apparent oxidative stress induced by the titania nanoparticle build up on the embryo chorion surface.

Aim. Aim of the study was to the effectiveness of various endometrial preparation protocols in IVF frozen embryo transfer cycles. Materials and methods. The study included 288 women, which were stratified into two groups depending on the onset of pregnancy: group 1 pregnancy + (n=92), group 2 pregnancy - (n=196). Then endometrium preparation features were evaluated. Results. The pregnancy rate after frozen-thawed embryo transfer was a bit higher in the natural menstrual cycle (41.2%) compared to the hormonal replacement therapy (30.0%); p=0.083. There were no significant differences in the use of various estrogen and progestogen drugs, the average estrogen dose, progestogen administration and the endometrium thickness. In the natural cycle, the odds ratio of pregnancy with the duration menstrual cycle from 28 to 30 days was 4.25 (95% CI 1.15; 17.23). Conclusion. Thus, the pregnancy rate is slightly higher in natural cycle frozen-thawed embryo transfer. However, the duration of the menstrual cycle (from 28 to 30 days) has a key effect on the effectiveness of the IVF program in this case.

The Na + / K + ATPase of cell membranes is one of the first to provide the formation of a primary response to the action of factors and initiates the mechanisms of formation of long-term adaptation. That is why the purpose of the study was to study the activity of Na-K pump in embryos and caviar of perch, roach, and ruffe under the action of different temperature and oxygen modes of the reservoir. The biological material of the studies was caviar, embryos and larvae of perch Perca fluviatilis L., roach Rutilus rutilus L. and ruffe Gymnocephalus cernuus L. Three ponds were selected, which, due to their location and degree of shading, differed in temperature conditions and, consequently, in the oxygen regime. The studies were conducted during April-May, at a time when perch, roach and ruffe spawning occur in natural water bodies. The maximum activity of the enzyme at the pre-cell stage was observed at a temperature of 16.3В°C and amounted to 4.67 Ојmol Pi mg protein-1 h-1, and when it reached an ambient temperature of 18.1В°C it decreased by 46.4% compared to the maximum. With the increase in the temperature of the aqueous medium above the norm decreased the activity of Na-K pump, which is due to the weakening of redox and increased anaerobic processes at low oxygen content in water. The activity of Na-K pump for perch embryos clearly shows that the most favorable temperatures for embryonic development are its lower values, in particular for the stage of eye pigmentation it is 14.9°C. After hatching at the pre-stage stage, maximum enzyme activity was observed at 16.3°C. For embryonic development of ruffe in the middle of the shell, the optimum water temperature is 15-16°C, but already at the stage of pre-cellulose, its optimum increased significantly, reaching 19-20.9°C. Roach is a more thermophilic species compared to perch and prefers higher water temperatures during embryonic development. It was noted that the activity of ATPase increased significantly with increasing water temperature. This may indicate a high adaptation of the roach to the temperature of the reservoirs, both under climatic norms and somewhat exceeding this norm. The best temperature for embryonic development of the roach is 16-17В°C, and during pre-embryonic stage its optimum increased to 20-21°C.

The review presents data on metabolites in the follicular fluid (FF) from the perspective of reproductive medicine and their use in order to predict outcomes of assisted reproductive technology (ART) programs. It considers various components of this biological medium (hormones, lipids, melatonin, etc.) with an assessment of their predictive value in prognosis of the effectiveness of in vitro fertilization (IVF) programs. The data on experimental directions in this field and the prospects for their use in clinical practice are presented. The article emphasizes that the growing clinical need and the unsolved problem of increasing the effectiveness of ART programs determine the need for further studies of the FF composition. Materials and methods. The review includes data related to this topic from foreign and Russian articles found in PubMed which were published in recent years. Results. Given the established fact of a direct effect of FF composition on growth and maturation of oocytes, and further, on the fertilization process, various FF metabolites are actively investigated as non-invasive markers of quality of oocytes/embryos. The article provides data on the experimental directions in this field and the prospects for their use in clinical practice. However, clinical studies of a relation between various FF metabolites levels and outcomes of IVF programs are contradictory. Conclusion. Owing large economic cost for treatment of infertility with IVF, there is need for expansion and intensification of studies to identify and use reliable predictors in prognosis of ART programs outcomes.

STUDY QUESTION How efficacious and safe are the current approaches to controlled ovarian stimulation (COS) aimed at fertility preservation (FP) in women with breast cancer (BC)? SUMMARY ANSWER In women with BC undergoing COS aiming at egg/embryo cryopreservation, letrozole-based protocols and those randomly started were equally effective compared with conventional COS, and the overall survival was similar between the women that proceeded to FP and those who did not. WHAT IS KNOWN ALREADY Cryopreservation of oocytes and embryos is an established method for FP in women with BC. Recent improvements to COS protocols include concomitant use of letrozole, random-cycle start day of stimulation and the use of GnRHa for the egg maturation trigger. To date, limited sample size of the available studies has not allowed investigation of differences in the efficacy of the different approaches to COS for FP in this patient population. STUDY DESIGN, SIZE, DURATION A prospective multicenter study with national coverage including 610 women with BC counseled between 1 January 1995 and 30 June 2017 at six Swedish FP regional programs. PARTICIPANTS/MATERIALS, SETTING, METHODS After counseling, 401 women elected to undergo COS. Treatments differed in the use or not of concomitant letrozole, a conventional or random-cycle day COS initiation and the use of hCG versus GnRHa trigger for oocyte maturation. Numbers of cryopreserved oocytes and embryos were defined as primary outcome. Pregnancy attempts, reproductive outcomes and long-term survival, investigated by the linking of individuals of the cohort to the total population register of the Swedish Tax Agency (up to 25 November 2018), were evaluated. MAIN RESULTS AND THE ROLE OF CHANCE Using letrozole or not resulted in similar numbers of oocytes and embryos cryopreserved (meanoocytes = 9.7 versus 10 and meanembryos 4.0 versus 5.3, respectively), similar to COS with random versus conventional start (meanoocytes 9.0 versus 10.6 and meanembryos 4.8 versus 4.8). In COS with letrozole, a GnRHa trigger was associated with a higher number of oocytes retrieved (P LIMITATIONS, REASONS FOR CAUTION Data on tumor characteristics and estrogen receptor (ER) status were not known for all women at the time of FP counseling and planning of COS, thus protocols with letrozole have been used for both estrogen-sensitive and non-estrogen-sensitive BC. For the same reason, subsequent adjustment for ERs in the BC or tumor characteristics as potential confounders were not performed as these parameters were not available and did not influence the provision of FP through COS. WIDER IMPLICATIONS OF THE FINDINGS The results of our study support the premise that recently introduced potential improvements to COS protocols for FP in women with BC are efficacious and safe. STUDY FUNDING/COMPETING INTEREST(S) This study was supported by research grants from the Swedish Cancer Society, the Stockholm County Council, the Percy Falk Stiftelsen, Radiumhemmets Forskningsfonder, The Swedish Breast Cancer Association and Karolinska Institutet to K.A.R.W. J.B. reports grants from Amgen, AstraZeneca, Pfizer, Roche, Sanofi-Aventis and Merck, outside the submitted work, and payment from UpToDate to Asklepios Medicine HB for a chapter on BC prediction and prognostication. All the other authors have no competing interests to report.

Graphical abstract, Highlights • Non-monotonic dose response relationship was detected in embryos exposed to DEHP. • Transient exposure to 0.1 ppb DEHP during early development inhibits oogenesis. • Transient exposure to 0.1 ppb DEHP during early development inhibits spermatogenesis. • Exposure to 0.001 ppb DEHP during early development reduces fertilization success. • Exposure to 0.001 ppb DEHP during early development reduces hatch rate in F1., Di-(2-ethylhexyl) phthalate (DEHP) is a well-known endocrine disruptor and it is ubiquitously distributed in the environment. However, very few studies have investigated the effects of short-term exposure to environmentally realistic concentrations of DEHP during early developmental stages and its chronic effects. This study monitored the long-term effects of transient exposure to DEHP in early life stages (F0 generation) and its subsequent fertilization success in F1 generation using Japanese medaka, Oryzias latipes, as model organism. Embryos (4 h post-fertilization, 4 hpf) of Japanese medaka were exposed to 0.001 ppb, 0.1 ppb, or 10 ppb DEHP for 21 days and returned to control water (without DEHP) for maturation (4 months old). At day 9 of the exposure study, mortality was significantly increased in medaka embryos (before hatching) treated with 0.001 ppb and 10 ppb DEHP. Continual exposure of young hatchlings for an additional 12 days (a total of 21 days of exposure) resulted in a significant increase in mortality in fish exposed to 0.001 ppb, 0.1 and 10 ppb DEHP. Significant reduction in egg production was observed in adult female medaka (4 months old) with prior exposure to 0.1 ppb and 10 ppb DEHP for 21 days during early development. Fertilization and hatching success were also significantly reduced in breeding pairs with prior exposure to 0.001 ppb, 0.1 ppb and 10 ppb DEHP during early life stage. Histological analysis of adult male gonads revealed a significant decline in mature sperm count accompanied by an increase in interstitial space in fish exposed to 0.1 ppb and 10 ppb DEHP during early development. Likewise, the amount of vitellogenic (mature) oocytes observed in the ovaries of adult female with transient exposure to 0.1 ppb and 10 ppb DEHP was significantly reduced when compared with the solvent control group. Our data suggest that transient exposure to ultra low concentrations of DEHP during sensitive time windows of development results in irreversible reproductive impairment which may impact fish populations negatively.

The present study aimed to investigate the effects of a combination of progesterone with different doses of E-17β on following end points: (1) ovarian follicular dynamics and emergence of a new follicular wave, and (2) superovulatory response and embryo yield. In Experiment 1, 28 ewes were randomly divided into four groups (n = 7) to receive either 2.0 mg, 1.0 mg, 0.5 mg or none E-17β one day after insertion of a progesterone device. The different doses of estradiol similarly delayed the moment of follicular emergence (overall mean = 3.1 ± 1.0 days vs. control group = 0.86 ± 1.0 days; P < 0.01), but the emergence of the new wave showed greater synchronization with the 0.5 mg dosage of E-17β. In Experiment 2, sixty-two donor ewes received an internal progesterone release device (day -1) for 7 d and 1 d after the insertion of this device (day 0) were allocated randomly to receive 0.5 mg of E-17β or only the vehicle (control group). Superstimulation was initiated on day 3 with the administration of 133 mg of pFSH in eight decreasing doses. Contrary to expectations, the protocol with the administration of 0.5 mg E-17β did not improve the percentage of donors with > 2 CL, the number of CL and the production of embryos (P > 0.05). It was concluded that the combination of progesterone and 0.5 mg E-17β was more efficient in synchronizing the emergence of the new follicular wave, however this approach seems to be unnecessary in ewe’s superovulation programs.

Today, cryopreservation of bovine embryo is essential to ensure its preservation while awaiting their valuation. However, the quality of the in vitro produced embryos is inferior to those in vivo produced, which does not allow to obtained equivalent gestation rate. During the freezing process, the membranes, mainly composed of lipids, undergo physical and chemical stress which can lead to lysis of embryonic cells. In this way, in order to improve the quality of in vitro produced bovine embryos, two tasks were carried out in parallel: (1) The acquisition of new scientific knowledge on the lipid profile of in vitro produced bovine embryos and the modulation of the lipid profile by the addition of omega 3 fatty acid with the objectives of increasing membrane fluidity and reducing the embryo cryosensitivity; (2) the acquisition of new scientific knowledge on the interest of CRYO3, in the formulation of synthetic media, for the cryopreservation of bovine embryos in vitro produced and biopsied. This work has demonstrated that the lipid profile of embryos is strongly impacted by the in vitro development and cryopreservation protocol. Modulating the lipid profile by adding omega 3 does not impact the development and cryosurvival of embryos but appears to be beneficial for improving embryonic quality. Finally, CRYO3 is an interesting candidate, making it possible to dispense with the usual media, containing derivatives of animal products, while improving the cryosurvival of the embryos., Aujourd’hui, la cryoconservation de l’embryon bovin est primordiale pour assurer sa préservation dans l’attente de sa valorisation. Cependant, la qualité des embryons produits in vitro est inférieure à celle de ceux produits in vivo ne permettant pas l’obtention de taux de gestation équivalents. Lors du processus de congélation, les membranes, majoritairement composées de lipides, subissent des contraintes physiques et chimiques pouvant aboutir à une lyse des cellules embryonnaires. Ainsi, afin d’améliorer la qualité des embryons bovins produits in vitro et biopsiés, deux tâches ont été menées en parallèle : (1) l’acquisition de nouvelles connaissances scientifiques sur le profil lipidique des embryons produits in vitro et la modulation de ce profil par l’ajout d’acides gras de type oméga 3 avec pour objectifs d’augmenter la fluidité membranaire et de diminuer la cryosensibilité des embryons; (2) l’acquisition de nouvelles connaissances scientifiques sur l’intérêt du CRYO3, dans la formulation de milieux de cryoconservation synthétiques, pour la cryoconservation des embryons bovins. Ces travaux ont permis de mettre en évidence que le profil lipidique des embryons est fortement impacté par le processus de production in vitro et les protocoles de cryoconservation. La modulation du profil lipidique par l’ajout d’oméga 3 n’impacte pas le développement et la cryosurvie des embryons mais semble bénéfique à l’obtention d’embryons de meilleure qualité. Enfin, le CRYO3 est un candidat intéressant permettant de se passer des milieux habituels, contenant des dérivés de produits animaux, tout en améliorant la cryosurvie des embryons.