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Increase in stress-related disorders in women begins post-puberty and persists throughout the lifespan. To characterize sex differences in stress response in early adulthood, we used functional magnetic resonance imaging while participants underwent a stress task in conjunction with serum cortisol levels and questionnaires assessing anxiety and mood. Forty-two healthy subjects aged 18-25 years participated (21M, 21F). Interaction of stress and sex in brain activation and connectivity were examined. Results demonstrated significant sex differences in brain activity with women exhibiting increased activation in regions that inhibit arousal compared to men during the stress paradigm. Women had increased connectivity among stress circuitry regions and default mode network, whereas men had increased connectivity between stress and cognitive control regions. In a subset of subjects (13F, 17M), we obtained gamma-aminobutyric acid (GABA) magnetic resonance spectroscopy in rostral anterior cingulate cortex (rostral ACC) and dorsolateral prefrotal cortex (dlPFC) and conducted exploratory analyses to relate GABA measurements with sex differences in brain activation and connectivity. Prefrontal GABA levels were negatively associated with inferior temporal gyrus activation in men and women and with ventromedial prefrontal cortex activation in men. Despite sex differences in neural response, we found similar subjective ratings of anxiety and mood, cortisol levels, and GABA levels between sexes, suggesting sex differences in brain activity result in similar behavioral responses among the sexes. These results help establish sex differences in healthy brain activity from which we can better understand sex differences underlying stress-associated illnesses., Competing Interests: Declaration of Competing Interest Dr. Goldstein is on the scientific advisory board and has an equity interest in Cala Health, a neuromodulation device company, but there is no conflict of interest with this study. The relationship is managed by the Mass General Brigham Office of Industry Interactions. Over the past 3 years, Dr. Pizzagalli has received consulting fees from Albright Stonebridge Group, Boehringer Ingelheim, Compass Pathways, Engrail Therapeutics, Neumora Therapeutics (formerly BlackThorn Therapeutics), Neurocrine Biosciences, Neuroscience Software, Otsuka, Sunovion, and Takeda; he has received honoraria from the Psychonomic Society (for editorial work) and Alkermes; he has received research funding from the Brain and Behavior Research Foundation, the Dana Foundation, Millennium Pharmaceuticals, and National Institute of Mental Health (NIMH); he has received stock options from Compass Pathways, Engrail Therapeutics, Neumora Therapeutics, and Neuroscience Software. No funding from these entities was used to support the current work, and all views expressed are solely those of the authors. Dr. Misra has served on the advisory board of Ipsen and Abbvie and served as a consultant for Abbvie and Sanofi, but no conflicts of interest with this work. No funding from these entities was used to support the current work, and all views expressed are solely those of the authors. The other authors have no financial disclosures., (Copyright © 2023 Elsevier B.V. All rights reserved.)

This study aimed to evaluate the ploidy and survival of larvae resulting from crosses between tetraploid females and diploid males of yellowtail tetra Astyanax altiparanae , both females (three diploids and three tetraploids) and males ( n = 3 diploids). Breeders were subjected to hormonal induction with pituitary gland extract from common carp fish ( Cyprinus carpio ). Females received two doses at concentrations of 0.3 and 3.0 mg/kg -1 body weight and at intervals of 6 h. Males were induced with a single dose of 3.0 mg/kg -1 applied simultaneously with the second dose in females. Oocytes from each diploid and tetraploid female were fertilized with semen from the same male, resulting in two crosses: cross 1 (diploid male and diploid female) and cross 2 (diploid male and tetraploid female). The procedures were performed with separate females (diploid and tetraploid) and diploid males for each repetition ( n = 3). For ploidy determination, 60 larvae from each treatment were analyzed using flow cytometry and cytogenetic analyses. As expected, flow cytometry analysis showed that progenies from crosses 1 and 2 presented diploid and triploid individuals, respectively, with a 100% success rate. The same results were confirmed in the cytogenetic analysis, in which the larvae resulting from cross 1 had 50 metaphase chromosomes and those from cross 2 had 75 chromosomes. The oocytes have a slightly ovoid shape at the time of extrusion. Diploid oocytes had a size of 559 ± 20.62 μm and tetraploid of 1025.33 ± 30.91 μm. Statistical differences were observed between eggs from crosses 1 and 2 ( P = 0.0130). No significant differences between treatments were observed for survival at the 2-cell stage ( P = 0.6174), blastula ( P = 0.9717), gastrula ( P = 0.5301), somite ( P = 0.3811), and hatching ( P = 0.0984) stages. In conclusion, our results showed that tetraploid females of the yellowtail tetra A. altiparanae are fertile, present viable gametes after stripping and fertilization using the 'dry method', and may be used for mass production of triploids. This is the first report of these procedures within neotropical characins, and which can be applied in other related species of economic importance.

Biotechniques, including surrogate propagation derived from primordial germ cell (PGC) transplantation, are valuable tools for the reconstitution of endangered fish species. Although promising, there are no previous studies reporting such approaches using neotropical fish species. The aim of this study was to establish germline chimeras in neotropical fish by using the yellowtail tetra Astyanax altiparanae as a model species of the order Characiformes. Germline chimeras were obtained after transplantation of PGCs cultivated under different conditions: saline medium and supplemented with DMEM, amino acids, vitamins, glutamine, pyruvate, and fetal bovine serum, and subsequently transplanted into A. altiparanae triploids and triploid hybrids from the cross between A. altiparanae (♀) and A. fasciatus (♂). The results indicate ectopic migration in host embryos after transplantation of PGCs cultivated in saline medium. However, PGCs cultivated in supplemented medium migrated to the region of the gonadal ridge in 4.5% of triploid and 19.3% in triploid hybrid. In addition, the higher expression of dnd1, ddx4 and dazl genes was found in PGCs cultivated in supplemented culture medium. This indicates that the culture medium influences the maintenance and development of the cultivated cells. The expression levels of nanos and cxcr4b (related to the differentiation and migration of PGCs) were decreased in PGCs from the supplemented culture medium, supporting the results of ectopic migration. This is the first study to report the transplantation of PGCs to obtain germline chimera in neotropical species. The establishment of micromanipulation procedures in a model neotropical species will open new insights for the conservation of endangered species.

Triploidization plays an important role in aquaculture and surrogate technologies. In this study, we induced triploidy in the matrinxã fish (Brycon amazonicus) using a heat-shock technique. Embryos at 2 min post fertilization (mpf) were heat shocked at 38°C, 40°C, or 42°C for 2 min. Untreated, intact embryos were used as a control. Survival rates during early development were monitored and ploidy status was confirmed using flow cytometry and nuclear diameter analysis of erythrocytes. The hatching rate reduced with heat-shock treatment, and heat-shock treatments at 42°C resulted in no hatching events. Optimal results were obtained at 40°C with 95% of larvae exhibiting triploidy. Therefore, we report that heat-shock treatments of embryos (2 mpf) at 40°C for 2 min is an effective way to induce triploid individuals in B. amazonicus.

This study interrogated factors which affect the appearance of secondary sexual characteristics, namely, fin spinelets (rigid dimorphic structure empirically associated with male sexual maturity in characids), in Astyanax altiparanae. Many variables such as the season of the year and several biotic components, including organism length, sex, phase of maturation, and the presence of gonads, were investigated. These factors were then associated with the physiological development of fin spinelets. The development of this trait is related to reproductive strategies but demonstrates considerable population variability as it is found throughout the year in some species but only during specific periods in others. Seventy-five specimens obtained from spontaneous spawn of farmed fish were arbitrarily grouped into small-, medium-, and large-sized groups in both summer and winter. Gonadal histology was performed to confirm each animal's sex and phase of maturation. Diaphanization of the fish was performed to visualize, count, and measure the fin spinelets. Finally, gonadectomization of some males was utilized to investigate the gonadal effect on the presence of fin spinelets. The present results show that the presence of fin spinelets is a secondary sexual characteristic of males which occurs independently of the season and is always present in males longer than 48 mm. However, in the summer, male specimens presented more rays with fin spinelets than during the winter. Furthermore, since fin spinelets were observed on immature males as well as spawning capable males, their presence cannot be directly associated with sexual maturity in male A. altiparanae, as previously supposed. Finally, gonadectomization resulted in an initial reduction in the length of fin spinelets. However, this trend was eventually normalized with time.

The aim of this study was to evaluate different post-shock temperatures for tetraploid induction in the yellowtail tetra Astyanax altiparanae. Newly fertilized eggs were divided into four groups, three were submitted to heat shock (40°C for 2 min) at 24 min post-fertilization (mpf) and another group remained without shock (control). Groups submitted to temperature shock were further separated at the following temperatures: 22°C, 26°C and 28°C. Survival among embryonic development was counted and at hatching the ploidy was analyzed by flow cytometry. The results showed that the post-shock temperature affects the parameters analyzed and, therefore, must be considered for optimization of the production of tetraploid in A. altiparanae. Those data are innovative and could be used in future studies of basic biology in this species.

Although the potential of surrogate propagation technology for aquaculture and conservation of Neotropical fish, the poor understanding of the host immune system may results in rejection and destruction of the donor material. Thus, it is necessary to study and to develop methods to evaluate the effects of immunosuppressive drugs employment and to evaluate the immunocompatibility between donor and receptor. Thus, the present study aimed to optimize a methodology to assess in vivo phagocytosis in Astyanax altiparanae using Saccharomyces cerevisiae and to evaluate their hematological response resultant from the inflammatory induction. To this, S. cerevisiae were labeled with Congo red and injected in the coelomic cavity of A. altiparanae at the concentration of 2.5 x 106 cells mL-1. A PBS solution and a non-injected group were kept as control. Fish blood was sampled and the phagocytic capacity and index were determined at 1, 2, 3 and 6 h post-injection (hpi). The yeast injection successfully stimulated phagocytosis, with the best result for phagocytosis assessment after 2 hpi. Moreover, it was achieved a high traceability of phagocytized and non-phagocytized yeast under optic microscopy analysis due to the Congo red labeling. The hematological profile was similar to usually observed in early infections, indicating lymphocyte migration to inflammatory site and increase in number of circulating phagocytes due to natural response to inflammatory stimulus. In conclusion, our method was efficient to assess in vivo phagocytosis in A. altiparanae and will be an important tool to evaluate the efficacy of immunosuppressive drugs in this species. Additionally, these results may serve as support for further studies in fish immunocompetence, both in laboratory and in field conditions.

SummaryIn this study we analyzed whether the in vivo storage of oocytes (time after ovulation until fertilization) affects the survival and the ploidy status of the yellowtail tetra Astyanax altiparanae. Fish were induced to spawn and, after ovulation, a small aliquot was stripped and immediately fertilized (positive control group). Subsequently, aliquots (~150 oocytes) were stripped and fertilized at various time points of 60, 120, 180 or 240 min. Developmental stages, abnormalities, survival and the ploidy status of the hatched larvae were examined. As expected, in the control group, 100% of the larvae were diploid. Conversely, triploid individuals were observed just at the 60 min treatment time point (0.6%). In vivo storage of oocytes also influenced the survival rates (P < 0.05); the 180 and 240 min samples, respectively, presented lower survival rates at gastrula (50.10±6.26% and 40.92±5.32%), and somite (17.80±5.14% and 4.41±2.76%) stages and lower hatching rates (12.01±4.04% and 4.41±2.76%). A higher percentage (99.27±0.40%) of normal larvae and only a few abnormal larvae (0.73±0.40%) were observed in the control group (P = 0.0000). This observation did not differ from that observed at the 60 min treatment point (P = 0.9976). A significant increase in the percentage of abnormalities was observed in the other treatments, and, after 240 min, the highest percentage of abnormal larvae was seen (P=0.0024; 83.33±16.67%). In conclusion, we showed that oocyte ageing had a significant effect on survival and may affect the ploidy status in A. atiparanae.

Social play is a highly rewarding behavior displayed mostly during the juvenile period. We recently showed that vasopressin V1a receptor (V1aR) blockade in the lateral septum (LS) enhances social play in male juvenile rats, but reduces it in females. Here, we determined whether the LS-AVP system modulates dopamine (DA) and/or norepinephrine (NE) neurotransmission in the LS to regulate social play behavior in sex-specific ways. Using microdialysis combined with retrodialysis, we demonstrated that both LS-AVP administration and social play exposure increased extracellular LS-DA release in females, but not in males. Pharmacological blockade of LS-DA receptors reduced social play in both sexes, but required a higher dose in females. This suggests that baseline LS-DA release is sufficient for social play in males, while increased LS-DA release is necessary for social play in females. Administration of a V1aR antagonist into the LS inhibited the social play-induced increase in extracellular LS-DA release in females. Furthermore, co-administration of the DA agonist apomorphine prevented the LS-V1aR blockade-induced decrease in social play in females. This suggests that LS-V1aR blockade reduces social play in females by dampening the rise in LS-DA release. Extracellular LS-NE release was enhanced in response to pharmacological manipulations of the LS-AVP system and to social play in males and/or females, but pharmacological blockade or stimulation of LS-NE receptors did not alter social play in either sex. Overall, we define a mechanism by which the LS-AVP system alters LS-DA neurotransmission differently in males than females resulting in the sex-specific regulation of juvenile social play behavior.

Environmental relevant concentrations of glyphosate-based herbicide as 50 µg l -1 , 300 µg l -1 and 1800 µg l -1 can affect sperm quality of yellowtail tetra fish Astyanax lacustris. Viability of sperm cells was impaired at 300 µg l -1 , a concentration that is within legal limits in U.S.A. waterbodies, while motility was impaired at 50 µg l -1 , which is the more stringent limit set in Brazilian law. Therefore, environment protection agencies must review regulations of glyphosate-based herbicides on water bodies., (© 2018 The Fisheries Society of the British Isles.)

SummaryThe aim of this study was to describe the effect of temperature on the fertilization, early developmental stages, and survival rate of two Neotropical catfishes Pimelodus maculatus and Pseudopimelodus mangurus. After fertilization, the eggs were incubated at 22°C, 26°C, and 30°C, which resulted in fertilization rates of 96.95 ± 1.79%, 98.74 ± 0.76%, and 98.44 ± 0.19% for P. maculatus and 96.10 ± 1.58%, 98.00 ± 0.63%, and 94.60 ± 2.09% for P. mangurus, respectively. For P. maculatus, hatching occurred after 22 h 30 min post-fertilization at 22°C, 16 h 30 min at 26°C, and 11 h 20 min at 30°C, and the hatching rates were 43.87 ± 7,46%, 57.57 ± 17.49%, and 53.63 ± 16.27%, respectively. For P. mangurus, hatching occurred after 28 h 30 min post-fertilization at 22°C and 17 h 30 min at 26°C with respective hatching rates of 45.4 ± 21.02% and 68.1 ± 12.67%. For this species, all embryos incubated at 30°C died before hatching. Additionally, for P. maculatus, the larvae from the lower (22°C) and higher temperatures (30°C) presented increased abnormality rates, as observed in the head, tail and yolk regions. The lowest abnormality rate was detected at 26°C, which was considered the optimal incubation temperature for both species. The developed protocol enables the manipulation of embryonic development, which is important for the application of reproductive biotechniques, including chimerism and chromosome-set manipulation. The data obtained here are also important for the surrogate propagation of this species as P. mangurus was recently categorized as an endangered fish species.

In fish, many factors can affect reproduction during in vitro fertilization, therefore determination of the factors that affect affecting gamete quality is needed. However, few studies have focused on gamete quality and the ploidy status. This study was conducted to elucidate whether oocyte storage can affect ploidy status, survival, and embryo viability in the characid species Astyanax altiparanae. Oocytes were stored in Dulbecco's phosphate-buffered saline (PBS) at 26°C, then aliquots were fertilized immediately after extrusion (control) and also after 60, 120, 180, and 240 min of storage. Fertilization and hatching rates were measured, and the developmental stages were analyzed at each stage before describing the main abnormalities. Ploidy status was analyzed by flow cytometry and blood smear. In the control group, 100% of the samples were diploid. After treatment for 60 min, 95.56 ± 4.44% samples were diploid and 4.44 ± 4.44% were triploid. After 120 min, 94.44 ± 9.62% of the samples was diploid and 5.56 ± 5.56% were triploid; 100% of the samples were diploid after 180 min and, after 240 min, there was no survival. In other treatments, the highest percentage of hatching was after 60 min (88.93 ± 5.15%; P = 0.015), and treatment with 180 min storage resulted in the highest percentage of abnormal larvae (95.76 ± 12.67%; P = 0.012). These results show that oocyte storage can affect ploidy status and may be an interesting parameter for analysis in studies on chromosome set manipulation and micromanipulation.

Primordial germ cell (PGC) transplant is a promising tool in aquaculture; however, successful use of this technique requires in depth knowledge of the early stages of embryo and larval development. The aim of this study was to analyse the effect of different temperatures (22, 26, and 30°C) on the early development of B. amazonicus. The newly fertilized eggs were distributed into tanks with controlled temperature and oxygenation. Samples were collected at pre-established times and analysed under light and fluorescence microscopy. Temperature influenced the speed and duration of each stage of early development, including hatching time. The highest pronuclei fusion rate was observed 8 min post-fertilization (mpf) at 22 and 26°C, and 6 mpf at 30°C. The duration of the 512-1000 blastomeres phase during in the blastocyst stage was 1 h 30 min at 22°C, and 25 min at 26 and 30°C. Hatching occurred at 24 h 30 mpf at 22°C, 16 h post-fertilization (hpf) at 26°C, and 11 h 30 mpf at 30°C. The rate of morphologically normal larvae was 88.34% at 22°C, 90.49% at 26°C, and 73% at 30°C. Malformations of the head, yolk sac, heart, and tail were observed in all temperatures. Nevertheless, B. amazonicus embryos were able to develop satisfactory in all three temperatures tested. These results enable embryo manipulation at different temperatures to optimize the micromanipulation time of embryos and larvae for biotechnological studies.

The aim of this study was to describe the morphology of gametes, post-fertilization events and subsequent temperature effects on the early developmental stages of the neotropical species Astyanax altiparanae. The sperm of this species presents a typical morphology of teleost sperm with a spherical head (diameter = 1.88 µm), midpiece (diameter = 0.75 µm) and a single flagellum (length = 18.67 µm). The extrusion of the second polar body and fusion of male and female pronucleus were reported for the first time in this species. Additionally, we observed the formation of the fertilization cone, which prevents polyspermic fertilization. Developmental stages at 22°C, 26°C and 30°C gave rise to fertilization rates at 91.12, 91.42 and 93.04% respectively. Hatching occurred at 25 hpf at 22°C, 16 hpf at 26°C and 11 hpf at 30°C and the hatching rates were 61.78%, 62.90% and 59.45%, respectively. At 22°C, the second polar body was extruded at ≈6 mpf and the male and female pronucleus fused at ≈10 mpf. This fundamental information is important for the field and opens up new possibilities in fish biotechnology, including micromanipulation and chromosome-set manipulation.

In this study, sex and age influenced the hematological profiles of Jundiá (Silver Catfish) Rhamdia quelen. Females showed lower levels of hemoglobin, young fish increased lymphocyte counts, and older fish increased hematocrit values. These results indicate that, depending on age and sex, the fish have disparate hematological profiles. For this reason, it is important to consider the sex and age of an R. quelen when examining the impact of environmental and management factors on this species in terms of their hematological profiles. Received May 24, 2015; accepted March 24, 2016.

The role for royal jelly (RJ) in promoting caste differentiation of honeybee larvae into queens rather than workers is well characterized. A recent study demonstrated that this poorly understood complex nutrition drives strikingly similar phenotypic effects in Drosophila melanogaster, such as increased body size and reduced developmental time, making possible the use of D. melanogaster as a model system for the genetic analysis of the cellular mechanisms underlying RJ and caste differentiation. We demonstrate here that RJ increases the body size of some wild-type strains of D. melanogaster but not others, and report significant delays in developmental time in all flies reared on RJ. These findings suggest that cryptic genetic variation may be a factor in the D. melanogaster response to RJ, and should be considered when attempting to elucidate response mechanisms to environmental changes in non-honeybee species.

One thousand five hundred cachara or tiger shovelnose catfish Pseudoplatystoma fasciatum, obtained from induced reproduction, were used to determine the onset of ovarian differentiation and development and to record the main characteristics of this process. Samples were collected from 0 to 240 days post-fertilization (dpf) and the results classified into stages I-XII. Ovarian formation was histologically detected for the first time when juveniles measured mean ± s.d. 51·5 ± 8·3 mm total length (LT ) at 39-45 dpf (stages I-V), with intense somatic cell proliferation originating in the ovarian cavity. Both LT and age of fish had a positive correlation (P < 0·001) with ovarian differentiation, but LT showed a greater correlation (r(2)  = 0·95) than age (r(2)  = 0·85), especially during the initial stages of development. From stages VI to VII, the ovarian cavity was enlarged and undifferentiated oogonia were present. At stage VIII, small projections formed in the ovarian stroma towards the ventral region of the gonad (future ovarian lamellae) and the basal membrane and differentiated oogonia nests could be seen. At stages IX and X, the germ cells entered meiosis and folliculogenesis was completed by stages XI and XII, which can be considered late in comparison to other Siluriformes. This study has demonstrated that ovarian differentiation in P. fasciatum begins with an intense proliferation of squamous epithelial cells (somatic cells) during the early stages of development and that sex inversion protocols could, thus, be applied successfully before this period. Furthermore, the results have demonstrated that both size and age can influence gonad differentiation and development in this species., (© 2016 The Fisheries Society of the British Isles.)

Studies have shown a relationship between circadian rhythm disruptions and type-2 diabetes. This investigation examined the effects of circadian disruption (6-h phase advances) on the progression of diabetes in a type-2 diabetic mouse model -TALLYHO/JngJ - and whether wheel-running can alleviate the effects of the phase advances. 6-h advances alter fasting glucose, glucose tolerance and insulin production. Wheel-running reduced body mass, improved glucose tolerance and reduced insulin in TALLYHO/JngJ and alleviated some of the changes in diabetic symptoms due to 6-h advances. These results indicate that individuals with type-2 diabetes can benefit from physical activity and exercise can be a countermeasure to offset the effects of an acute phase advance.

Bipolar patients have a high prevalence of comorbid alcohol use and abuse disorders, while chronic alcohol drinking may increase the presence and severity of certain symptoms of bipolar disorder. As such, there may be many individuals that are prescribed lithium to alleviate the manic symptoms of bipolar disorder, but also drink alcohol concurrently. In addition, both alcoholics and individuals with bipolar disorder often exhibit disruptions to their sleep-wake cycles and other circadian rhythms. Interestingly, both ethanol and lithium are known to alter both the period and the phase of free-running rhythms in mammals. While lithium is known to lengthen the period, ethanol seems to shorten the period and attenuate the responses to acute light pulses. Therefore, the present study aimed to determine whether ethanol and lithium have opposing effects on the circadian pacemaker when administered together. C57BL/6J mice were provided drinking solutions containing lithium, alcohol, or both, and their free-running rhythms along with their response to photic phase shifts were investigated. Mice treated with lithium displayed period lengthening, which was almost completely negated when ethanol was added. Moreover, ethanol significantly attenuated light-induced phase delays while the addition of lithium partially restored this response. These results indicate that alcohol and lithium have opposing effects on behavioral circadian rhythms. Individuals with bipolar disorder who are prescribed lithium and who drink alcohol might be inadvertently altering their sleep and circadian cycles, which may exacerbate their symptoms., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Betta splendens is a very important ornamental species. The current paper describes the embryonic and larval development of B. splendens under stereomicroscopy and scanning electron microscopy. Eggs and larvae from natural spawning were collected at different developmental stages at previously established intervals and analysed. The eggs of B. splendens are yellowish, clear, spherical, demersal, translucent and telolecithal with a large amount of yolk. Between 0-2 h post-initial collection (hpIC), the eggs were at the egg cell, first cleavage and morula stages. The blastula stage was identified at 2-3 hpIC and the early gastrula phase was observed at 3-4 hpIC with 20% epiboly, which was finalized after 13-18 hpIC. When the pre-larvae were ready to hatch, the appearance of somites and the free tail were observed, at 23-25 hpIC. At 29 hpIC, the majority of larvae had already hatched at an average temperature of 28.4 ± 0.2°C. The newly hatched larvae measured 2.47 ± 0.044 mm total length. The mouth opened at 23 h post-hatching (hPH) and the yolk sac was totally absorbed at 73 hPH. After 156 hPH, the heart was pumping blood throughout the entire larval body. The caudal fin, operculum and eyes were well developed at 264 hPH. When metamorphosis was complete at 768 hPH, the larvae became juveniles. The current study presents the first results about early development of B. splendens and provides relevant information for its reproduction, rearing and biology.

Groups of one hundred Brycon orbignyanus embryos at the stage of blastopore closure were subjected to different cooling protocols. Different combinations and concentrations of cryoprotectants were tested: sucrose, methanol, ethylene glycol and dimethyl sulfoxide (Me2SO); at different temperatures (0.0±2.0°C and 8.0±2.0°C) and refrigeration times (6, 10, 24, 72 and 168 h), with the exception of the positive control (incubation without previous cooling). At the end of each refrigeration time, the embryos were acclimatized, rehydrated and incubated to determine hatching, survival and deformity rates. Morphological analysis of embryos was also carried out. The results showed that temperature and refrigeration time are critical factors for embryo survival. No embryos survived after 24, 72 and 168 h of refrigeration. Furthermore, when the refrigeration time increased from 6 to 10h and the temperature decreased from 8.0±2.0°C to 0.0±2.0°C, mortality rates increased significantly. It was also found that in all protocols dead eggs and/or larvae with some degree of deformity were present. The main larval deformities observed were the malformation of the head, tail, yolk sac, vertebral column and eyes., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Two accessions of ornamental pepper Capsicum annuum L., differing in most of the characters studied, were crossed, resulting in the F1 generation, and the F2 generation was obtained through self-fertilization of the F1 generation. The backcross generations RC1 and RC2 were obtained through crossing between F1 and the parents P1 and P2, respectively. Morpho-agronomic characterization was performed based on the 19 quantitative descriptors of Capsicum. The data obtained were subjected to generation analysis, in which the means and additive variance (σa(2)), variance due to dominance deviation (σd(2)), phenotypic variance (σf(2)), genetic variance (σg(2)) and environmental variance (σm(2)) were calculated. For the full model, we estimated the mean effects of all possible homozygotes, additives, dominants, and epistatics: additive-additive, additive-dominant, and dominant-dominant. For the additive-dominant model, we estimated the additive effects, dominant effects and mean effects of possible homozygotes. The character fruit dry matter had the lowest value for broad sense heritability (0.42), and the highest values were found for fresh matter and fruit weight, 0.91 and 0.92, respectively. The lowest value for narrow sense heritability was for the minor fruit diameter character (0.33), and the highest values were found for seed yield per fruit and fresh matter, 0.87 and 0.84, respectively. The additive-dominant model explained only the variation found in plant height, canopy width, stem length, corolla diameter, leaf width, and pedicel length, but in the other characters, the epistatic effects showed significant values.

The objective of this study was to determine the effects of the general and specific combining abilities (GCA and SCA, respectively) of 15 characteristics and to evaluate the most promising crosses and the reciprocal effect between the hybrids of six parents of the Capsicum annuum species. Six parents, belonging to the Horticultural Germplasm Bank of Centro de Ciências Agrárias of Universidade Federal da Paraíba, were crossed in complete diallel manner. The 30 hybrids generated and the parents were then analyzed in a completely randomized design with three replicates. The data were submitted to analysis of variance at 1% probability, and the means were grouped by the Scott-Knott test at 1% probability. The diallel analysis was performed according to the Griffing method, model I and fixed model. Both additive and non-additive effects influenced the hybrids' performance, as indicated by the GCA/SCA ratio. The non-additive effects, epistasis and/or dominance, played a more important role than the additive effects in pedicel length, pericarp thickness, fresh matter, dry matter content, seed yield per fruit, fruit yield per plant, days to fructification, and total soluble solids. The GCA effects were more important than the SCA effects in the fruit weight, fruit length and diameter, placenta length, yield, vitamin C, and titratable acidity characteristics. The results found here clearly show that ornamental pepper varieties can be developed through hybridization in breeding programs with C. annuum.