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This work is structured in two chapters: 1) It is elaborated it in the format of a review article, with topics related to Aquaculture and physiology of teleosts, with emphasis on Nile tilapia. 2) It refers to the study, in an intensive culture system, of the performance of tilapia submitted to different photoperiods, during 6 months (180 days). It addresses the objectives, methodology and presentation and discussion of the results. The objectives were: to identify the patterns of somatic growth, muscle growth, energy mobilization and reproduction of tilapia throughout 180 days submitted to different photoperiods. For this purpose, we set up a recirculation system with 9 water tanks (1000L each), with 3 tanks each photoperiod (T1=24Light:0Dark; T2=18L:06D and T3=12D:12D). We stocked embryos in incubators, then in hatchery, and finally in water tanks (n=142 animals/each). The tilapia presented varied performances depending on the biometric variables and photoperiods. Mortality was considerable in the first 15 days of live with significant mortality up to 30 days with significant differences (p180μm, that started to be identified from day 90. The hepatic glycogen showed significant differences as an function of photoperiods on days 60, 90, 120 and 150((p180μm que começaram a ser identificadas a partir do dia 90. O glicogênio hepático apresentou diferenças significativas em função dos fotoperíodos nos dias 60, 90, 120 e 150 (p

Calcium balance is of paramount importance for vertebrates. In fish, the endocrine modulators of calcium homeostasis include the stanniocalcin (STC), and some members of the parathyroid hormone (PTH) family, such as the PTH-related protein (PTHrP), acting as antagonists. STC is ubiquitously expressed in higher vertebrates. In turn, bony fish exhibit specific STC-producing glands named the corpuscles of Stannius (CS). Previous studies pointed to a calcium-sensing receptor (CaSR) involvement in the secretion of STC, but little is known of the involvement of other putative regulators. The CS provides a unique model to deepen the study of STC secretion. We developed an ex vivo assay to culture CS of fish and a competitive ELISA method to measure STC concentrations. As expected, STC released from the CS responds to CaSR stimulation by calcium, calcimimetics, and calcilytic drugs. Moreover, we uncover the presence (by PCR) of two PTHrP receptors in the CS, e.g., PTH1R and PTH3R. Thus, ex vivo incubations revealed a dose-response inhibition of STC secretion in response to PTHrP at basal Ca2+ concentrations. This inhibition is achieved through specific and reversible second messenger pathways (transmembrane adenylyl cyclases and phospholipase C), as the use of specific inhibitors highlights. Together, these results provide evidence for endocrine modulation between two antagonist hormones, STC and PTHrP. info:eu-repo/semantics/publishedVersion

We review the insertion of mitochondrial DNA (mtDNA) fragments into nuclear DNA (NUMTS) as a general and ongoing process that has occurred many times during genome evolution. Fragments of mtDNA are generated during the lifetime of organisms in both somatic and germinal cells, by the production of reactive oxygen species in the mitochondria. The fragments are inserted into the nucleus during the double-strand breaks repair via the non-homologous end-joining machinery, followed by genomic instability, giving rise to the high variability observed in NUMT patterns among species, populations, or genotypes. Some de novo produced mtDNA insertions show harmful effects, being involved in human diseases, carcinogenesis, and ageing. NUMT generation is a non-stop process overpassing the Mendelian transmission. This parasitic property ensures their survival even against their harmful effects. The accumulation of mtDNA fragments mainly at pericentromeric and subtelomeric regions is important to understand the transmission and integration of NUMTs into the genomes. The possible effect of female meiotic drive for mtDNA insertions at centromeres remains to be studied. In spite of the harmful feature of NUMTs, they are important in cell evolution, representing a major source of genomic variation.

Individuals vary in their immune response and, as a result, some are more susceptible to infectious disease than others. Little is known about the nature of this individual variation in natural populations, or which components of immune pathways are most responsible, but defining this underlying landscape of variation is an essential first step to understanding the drivers of this variation and, ultimately, predicting the outcome of infection. We describe transcriptome-wide variation in response to a standardised immune challenge in wild field voles. We find that genes (hereafter 'markers') can be categorised into a limited number of types. For the majority of markers, the response of an individual is dependent on its baseline expression level, with significant enrichment in this category for conventional immune pathways. Another, moderately sized, category contains markers for which the responses of different individuals are also variable but independent of their baseline expression levels. This category lacks any enrichment for conventional immune pathways. We further identify markers which display particularly high individual variability in response, and could be used as markers of immune response in larger studies. Our work shows how a standardised challenge performed on a natural population can reveal the patterns of natural variation in immune response.

The demographic trend of a species depends on the dynamics of its local populations, which can be compromised by local or by global phenomena. However, the relevance of local and global phenomena has rarely been investigated simultaneously. Here, we tested whether local phenomena compromised a species’ demographic trend using the Eurasian common lizard Zootoca vivipara, the terrestrial reptile exhibiting the widest geographic distribution, as a model species. We analyzed the species’ ancient demographic trend using genetic data from its 6 allopatric genetic clades and tested whether its demographic trend mainly depended on single clades or on global phenomena. Zootoca vivipara’s effective population size increased since 2.3 million years ago and started to increase steeply and continuously from 0.531 million years ago. Population growth rate exhibited 2 maxima, both occurring during global climatic changes and important vegetation changes on the northern hemisphere. Effective population size and growth rate were negatively correlated with global surface temperatures, in line with global parameters driving long-term demographic trends. Zootoca vivipara’s ancient demography was neither driven by a single clade, nor by the 2 clades that colonized huge geographic areas after the last glaciation. The low importance of local phenomena, suggests that the experimentally demonstrated high sensitivity of this species to short-term ecological changes is a response in order to cope with short-term and local changes. This suggests that what affected its long-term demographic trend the most, were not these local changes/responses, but rather the important and prolonged global climatic changes and important vegetation changes on the northern hemisphere, including the opening up of the forest by humans., J.L.H. was supported by a Spanish MINECO grant IJCI-2015-23618. Project funds were provided by the Spanish Ministry of Education and Science [CGL2012-32459, CGL2016-76918 AEI/FEDER, UE to P.S.F.].

ilustraciones, diagramas, tablas En Colombia la producción de pollo de engorde se realiza de manera anual en todos los pisos térmicos y en galpones abiertos. La industria avícola colombiana de pollo de engorde se a desplazado a las zonas mas cálidas buscando cercanía con regiones altamente productoras de cereales por tanto es común ver grandes granjas en zonas cuya temperatura ambiental sobrepasan los 30ºC. Los nutricionistas usan como estrategias de alimentación para climas cálidos “dietas frías” en donde se reemplaza la fuente energética proveniente de los cereales por fuentes de alta concentración de energía como las grasas y aceites para reducir la pérdida de calor total a un ambiente que de por si ya esta saturado de calor. 324 hembras de la línea Ross 308 fueron alojadas al azar en jaulas y distribuidas en nueve tratamientos, todas bajo un mismo ambiente de crianza, la toma de datos se realizó en tres horarios 6 a.m., 12 p.m. y 3 p.m., durante los días 21, 28 y 42 de vida, con seis repeticiones por tratamiento. No hubo diferencias significativas entre tratamientos y su efecto sobre el calor total y respuesta fisiológica, pero la edad y la hora del día si lo tuvieron. (Texto tomado de la fuente) In Colombia, broiler production is carried out annually in all thermal floors and in open poultry houses. The Colombian broiler poultry industry has moved to warmer areas in search of proximity to high cereal producing regions, so it is common to see large farms in areas where the ambient temperature exceeds 30ºC. Nutritionists use "cold diets" as feeding strategies for hot climates where the energy source from cereals is replaced by high energy sources such as fats and oils to reduce the total heat loss to an environment that is already saturated with heat. 324 females of the Ross 308 line were randomly housed in cages and distributed in nine treatments, all under the same rearing environment. Data were collected at three times, 6 a.m., 12 p.m. and 3 p.m., on days 21, 28 and 42 of life, with six replicates per treatment. There were no significant differences between treatments and their effect on total heat and physiological response, but age and time of day did. Facultad de Ciencias Agrarias - Universidad Nacional de Medellin CEAGRO Maestría Magíster en Ciencias Agrarias Medio ambiente y producción agraria sostenible Área Curricular en Producción Agraria Sostenible

The fatty acid elongase elongation of very long-chain fatty acids protein 2 (ELOVL2)controls the elongation of polyunsaturated fatty acids (PUFA) producing precursors for omega-3,docosahexaenoic acid (DHA), and omega-6, docosapentaenoic acid (DPAn-6)in vivo. Expectedly,Elovl2-ablation drastically reduced the DHA and DPAn-6 in liver mitochondrial membranes. Unex-pectedly, however, total PUFAs levels decreased further than could be explained by Elovl2 ablation.The lipid peroxidation process was not involved in PUFAs reduction since malondialdehyde-lysine(MDAL) and other oxidative stress biomarkers were not enhanced. The content of mitochondrialrespiratory chain proteins remained unchanged. Still, membrane remodeling was associated withthe high voltage-dependent anion channel (VDAC) and adenine nucleotide translocase 2 (ANT2),a possible reflection of the increased demand on phospholipid transport to the mitochondria. Mi-tochondrial function was impaired despite preserved content of the respiratory chain proteins andthe absence of oxidative damage. Oligomycin-insensitive oxygen consumption increased, and coeffi-cients of respiratory control were reduced by 50%. The mitochondria became very sensitive to fattyacid-induced uncoupling and permeabilization, where ANT2 is involved. Mitochondrial volume andnumber of peroxisomes increased as revealed by transmission electron microscopy. In conclusion,the results imply that endogenous DHA production is vital for the normal function of mouse livermitochondria and could be relevant not only for mice but also for human metabolism. This study was supported by grants from the Swedish Science Council (VR-NT 2017-04715and VR-MT 2019-01508). This research was also funded in part by the Spanish Ministry of Science,Innovation, and Universities (grant RTI2018-099200-B-I00), and the Generalitat of Catalonia: Agencyfor Management of University and Research Grants (2017SGR696) to R.P. This study was co-financedby FEDER funds from the European Union (“A way to build Europe”). IRB Lleida is a CERCAProgramme/Generalitat of Catalonia. Open access funding was provided by Stockholm University,Sweden.

Marine mammals rely on their diving capacity to survive as this determines their foraging efficiency. Ultimately, their anatomy and physiological capacity, and the limitations imposed by the environment determine the maximal time underwater. Thus, the behavioral decisions undertaken by marine mammals would be related with the different combination of these factors. As air breathing mammals, respiratory function may alter the diving capacities and limit foraging. Further, respiratory disease has been reported as one of the major causes of mortality in these species and may have consequences for their respiratory function and diving capacities. In addition, the ability of marine mammals to efficiently use the available O2 stores during diving has been recognized as an important component that determines diving behavior and the duration of the breath-hold. However, the increasing human activity in the marine ecosystem (e.g., climate change, overfishing, contamination, etc.) is resulting in environmental alterations that could force marine mammals to perform dives beyond their physiological scope. In addition, these perturbations may disrupt the normal physiological mechanisms that enhance diving, or may also increase their susceptibility to disease, which could have consequences on their diving capacity. Therefore, a better understanding of species-specific normal respiratory function and capacity could help improve our understanding about respiratory limitations and the functional consequences of respiratory disease, and how these affect the diving capabilities of marine mammals. In addition, studies evaluating the metabolic rate, or O2 consumption rate, during diving in different species will help understand the energetic requirements of underwater behaviors, such as foraging or travelling. This information could help understand interspecific limitations that drive behavioral decisions within a changing environment. Such information would be vital to enhance conservation efforts of those populations suffering increased direct or indirect impacts that could affect their future survival. The present thesis is aimed to provide basic information about respiratory function and energetic requirements during in-water activities in one of the species facing an increased habitat loss: the Pacific walrus (Odobenus rosmarus divergens). In addition, the present investigation assessed the use of spirometry as a non-invasive diagnostic tool to evaluate respiratory health and the functional consequences of respiratory disease in the bottlenose dolphin (Tursiops truncatus). These objectives were performed with the participation of trained animals housed in professional care and were developed in three independent chapters briefly summarized below: In Chapter I, basic respiratory function was measured in three adult Pacific walruses. The results showed an enhanced ventilatory capacity (e.g., higher tidal volume and lung compliance, and high respiratory flows maintained over the entire respiratory manoeuvre) compared with terrestrial mammals. Respiratory function was assessed in different body positions on land and in water, which showed flow limitations while lying on land and increased respiratory flows when in water. These results provide basic information to understand respiratory limitations in this species, and suggest that respiratory function in semi-aquatic marine mammals should be evaluated both on land and in water. In Chapter II, lung function testing (spirometry) was used as a non-invasive method to assess respiratory health in three adult bottlenose dolphins. Lung health was assessed through the development of lung function indices adapted for the respiratory capacity of dolphins, and the evaluation of the flow-volume relationship. The results were compared with clinical diagnostics (e.g., blood and sputum samples) and chest radiographs, and showed that lung function testing could detect respiratory disease, evaluate functional changes, and assess treatment efficacy in dolphins trained to exhale maximally while in water. In addition, the results indicated that spirometry could provide diagnostic information in stranded individuals while breathing spontaneously. Thus, the results presented in this chapter showed that lung function testing is a potential non-invasive method to evaluate respiratory health in trained and stranded dolphins. In Chapter III, the O2 consumption rate was measured in three adult Pacific walruses while floating at the water surface, and during short and shallow stationary dives and subsurface swimming. The results are similar to previously results reported for adult pinnipeds where measured metabolic rates during inactive periods (on land or in water) were greater than those expected from similarly sized terrestrial mammals. In addition, metabolic rate during diving was lower as compared with periods at the surface, as previously reported for other pinniped species. This shows that the walrus has behavioural or physiological means to limit metabolic costs during diving. The data presented in this chapter could help improve previous bioenergetic models aimed to quantify the consequences of environmental change in the Pacific walrus.

In this study, we assessed the effect of environmental salinity and pH as independent factors on larval survival of Atlantic bluefin tuna (ABFT –Thunnus thynnus) together with their whole-body Na+/K+-ATPase and v-type H+-ATPase activities. Fertilized eggs of ABFT were obtained from a spontaneous spawning of broodstock in the farming facilities at El Gorguel (Cartagena, SE Spain) and were transferred to facilities of the Spanish Institute of Oceanography (IEO) in Mazarrón (SE Spain). In a first experiment, eggs (200 fertilized eggs L-1 per treatment, in 3 replicates) were exposed to different salinities treatments and constant pH 8.0 (control) until hatch was completed (50 h post- fertilization, hpf, at 23 ºC): 27, 30, 33, 36, 37, 38 (control), 39, 40, 43, 46 and 49 ppt. In a second experiment eggs (200 fertilized eggs L-1, in 3 replicates) were exposed to seawater salinity (SW: 38 ppt) and four reduced pH treatments until hatch was completed (50 hpf at 23 ºC): 8.0 (control), 7.7, 7.5 and 7.3. An inverse „„U-shaped‟‟ relationship was observed between environmental salinity and number of hatched larvae. An opposite pattern was observed for both Na+/K+-ATPase and H+-ATPase activities in hatched larvae, increasing both activities in groups exposed to extreme salinities. Thus, larval survival was higher at intermediate salinities and lower at the extreme salinities tested. These results suggest higher survival rates with lower active pumps activities. No significant differences in larval survival were observed with pH treatment, but lower H+-ATPase activity was detected at control environmental pH (pH 8.0). Survival results are discussed in terms of osmoregulatory cost adapting to a salinity and pH predicted for the near future scenarios., SI

The circadian system is formed by a network of oscillators located in central and peripheral tissues that are tightly linked to generate rhythms in vertebrates to adapt the organism to the cyclic environmental changes. The nuclear receptors PPARs, REV-ERBs and RORs are transcription factors controlled by the circadian system that regulate, among others, a large number of genes that control metabolic processes for which they have been proposed as key genes that link metabolism and temporal homeostasis. To date it is unclear whether these nuclear receptors show circadian expression and which zeitgebers are important for their synchronization in fish. Therefore, the objective of this study was to investigate whether the two main zeitgebers (light-dark cycle and feeding time) could affect the synchronization of central (hypothalamus) and peripheral (liver) core clocks and nuclear receptors in goldfish. To this aim, three experimental groups were established: fish under a 12 h light-12 h darkness and fed at Zeitgeber Time 2; fish with the same photoperiod but randomly fed; and fish under constant darkness and fed at Circadian Time 2. After one month, clock genes and nuclear receptors expression in hypothalamus and liver and circulating glucose were studied. Clock genes displayed daily rhythms in both tissues of goldfish if the light-dark cycle was present, with shifted-acrophases of negative and positive elements, as expected for proper functioning clocks. In darkness-maintained fish hypothalamic clock genes were fully arrhythmic while the hepatic ones were still rhythmic. Among studied nuclear receptors, in the hypothalamus only nr1d1 was rhythmic and only when the light-dark cycle was present. In the liver all nuclear receptors were rhythmic when both zeitgebers were present, but only nr1d1 when one of them was removed. Plasma glucose levels showed significant rhythms in fish maintained under random fed regimen or constant darkness, with the highest levels at 1-h postprandially in all groups. Altogether these results support that hypothalamus is mainly a light-entrained-oscillator, while the liver is a food-entrained-oscillator. Moreover, nuclear receptors are revealed as clear outputs of the circadian system acting as key elements in the timekeeping of temporal homeostasis, particularly in the liver.

La instancia de evaluación y la modalidad que se emplea para valorar los contenidos aprendidos es una parte esencial en el trayecto de formación de los estudiantes. Ya sea, porque nos permite acceder a los conocimientos que poseen, previos a desarrollar un contenido, señalar un seguimiento del proceso de aprendizaje y de las posibles dificultades que atravesaron los alumnos en diferentes etapas del recorrido, o, finalmente, evaluar los aprendizajes obtenidos y lograr un cierre a la materia al final de la misma. Además, como contraparte a esto, nos da información acerca de que tan eficientes son los procesos y métodos de enseñanza que los docentes están llevando a cabo y puntos críticos donde puedan aplicarse modificaciones para corregir las posibles fallas en los mismos. Una buena evaluación hace buena la actividad de enseñanza y buena la actividad de aprender, manteniendo un equilibrio saludable en el proceso educativo. Frecuentemente, los procesos evaluativos tradicionales (mediante pruebas y/o exámenes) están asociados a efectos adversos en los alumnos, como: frustraciones, competitividad entre los pares, ansiedad y el uso de la evaluación como una mera valoración instrumental de los aprendizajes. En el marco de este contexto, encontramos la cátedra de la cual formo parte y cuyas asignaturas se apoyan en sistemas de evaluación que se caracterizan por un alto número de instancias de examen, volviéndose engorrosas y frustrantes para los alumnos (principalmente por tratarse de una materia troncal de las carreras y la complejidad de la misma), al punto que generan tasas altas de abandonos o pérdidas de regularidad, múltiples re-cursadas de la materia, etc., en los alumnos. El objetivo del presente TFI es elaborar una propuesta de evaluación que incorpore, dentro del programa de la materia Fisiología Animal, instancias evaluativas de pares entre los alumnos, en las cuales los mismos estudiantes oficiarían de evaluadores de sus compañeros y viceversa. Por lo tanto, la propuesta de innovación se presenta como una alternativa a la evaluación tradicional, con la intención de enriquecer el proceso de aprendizaje de los alumnos y favorecer la permanencia durante el trayecto formativo., Asesora: Elisa Marchese, Facultad de Ciencias Veterinarias

In fish, most hormonal productions of the pituitary gland display daily and/or seasonal rhythmic patterns under control by upstream regulators, including internal biological clocks. The pineal hormone melatonin, one main output of the clocks, acts at different levels of the neuroendocrine axis. Melatonin rhythmic production is synchronized mainly by photoperiod and temperature. Here we aimed at better understanding the role melatonin plays in regulating the pituitary hormonal productions in a species of scientific and economical interest, the euryhaline European sea bass Dicentrarchus labrax. We investigated the seasonal variations in mRNA abundance of pituitary hormones in two groups of fish raised one in sea water (SW fish), and one in brackish water (BW fish). The mRNA abundance of three melatonin receptors was also studied in the SW fish. Finally, we investigated the in vitro effects of melatonin or analogs on the mRNA abundance of pituitary hormones at two times of the year and after adaptation to different salinities. We found that (1) the reproductive hormones displayed similar mRNA seasonal profiles regardless of the fish origin, while (2) the other hormones exhibited different patterns in the SW vs. the BW fish. (3) The melatonin receptors mRNA abundance displayed seasonal variations in the SW fish. (4) Melatonin affected mRNA abundance of most of the pituitary hormones in vitro; (5) the responses to melatonin depended on its concentration, the month investigated and the salinity at which the fish were previously adapted. Our results suggest that the productions of the pituitary are a response to multiple factors from internal and external origin including melatonin. The variety of the responses described might reflect a high plasticity of the pituitary in a fish that faces multiple external conditions along its life characterized by marked daily and seasonal changes in photoperiod, temperature and salinity.

Aims: Nitric oxide (NO) and hydrogen sulfide (H2S) are involved in nerve-mediated corpus cavernosum (CC) relaxation. Expression of phosphodiesterase type 5 (PDE5) and type 4 (PDE4), cyclic guanosine monophosphate (cGMP)- and cyclic adenosine monophosphate (cAMP)-specific, respectively, has been described and PDE5- and PDE4-inhibitors induce cavernous smooth muscle relaxation. Whereas the NO/cGMP signaling pathway is well established in penile erection, the cAMP-mediated mechanism is not fully elucidated. The aim of this study is to investigate the localization and the functional significance of PDE4 in rat CC tone regulation. Main methods: We performed immunohistochemistry for the detection of the PDE4A isoenzyme. Isometric tension recordings for roflumilast and tadalafil, PDE4 and PDE5 inhibitors, respectively, electrical field stimulation (EFS) and β-adrenoceptor agonist isoproterenol and endogenous H2S production measurement. Key findings: A marked PDE4A expression was detected mainly localized in the nerve cells of the cavernous smooth muscle. Furthermore, roflumilast and tadalafil exhibited strong corpus cavernous relaxations. Endoge-nous H2S production was decreased by NO and H2S synthase inhibitors and increased by roflumilast. Isopro-terenol- and EFS-induced relaxations were increased by roflumilast. Significance: These results indicate that PDE4A is mainly expressed within the nerves cells of the rat CC, where roflumilast induces a potent corpus cavernous relaxation per se and potentiates the response induced by β-adrenoceptor activation. The fact that roflumilast enhances H2S production, as well as EFS-elicited responses suggests that PDE4 inhibitors modulate, in a positive feedback fashion, nerve-mediated relaxation induced by gasotransmitters, thus indicating a key role for neuronal PDE4 in penile erection.

Simple Summary For the first time, glucocorticoid actions of corticosteroids are evidenced in vivo and ex vivo in sharks, highlighting the importance of carbohydrate metabolism in situations of high-energy expenditure in this taxonomical group. Long-term (7 days) in vivo administration of dexamethasone (DEX, a synthetic glucocorticoid) decreased 1α-hydroxycorticosterone (1α-OHB, the main corticosteroid hormone in sharks), while also modified carbohydrates metabolism in liver and white muscle. Short-term (1 to 5 h) ex vivo incubation of liver and muscle explants with cortisol (corticosteroid not present in sharks) and DEX revealed glucose secretion mediated by glucocorticoid receptors (GR), as seen by the employment of mifepristone (a GR inhibitor). Abstract Corticosteroids are hormones produced in vertebrates exerting gluco- and mineralocorticoid actions (GC and MC) mediated by specific receptors (GR and MR, respectively). In elasmobranchs, the major circulating corticosteroid is the 1α-hydroxycorticosterone (1α-OHB). This hormone acts as a MC, but to date its role as a GC has not been established. As there is no 1α-OHB standard available, here we employed a set of in vivo and ex vivo approaches to test GC actions of other corticosteroids in the lesser spotted catshark (Scyliorhinus canicula). Dexamethasone (DEX, a synthetic corticosteroid) slow-release implants decreased plasma 1α-OHB levels after 7 days, and modified carbohydrates metabolism in liver and white muscle (energy stores and metabolic enzymes). In addition, ex vivo culture of liver and white muscle explants confirmed GC actions of corticosteroids not naturally present in sharks (cortisol and DEX) by increasing glucose secretion from these tissues. Dose–response curves induced by cortisol and DEX, altogether with the use of specific GR inhibitor mifepristone, confirmed the involvement of GR mediating glucose secretion. This study highlights the influence of corticosteroids in the glucose balance of S. canicula, though the role of 1α-OHB as a GC hormone in sharks should be further confirmed.

Cortisol is the main glucocorticoid hormone promoting compensatory metabolic responses of stress in teleosts. This hormone acts through genomic and membrane-initiated actions to exert its functions inside the cell. Experimental approaches, using exogenous cortisol administration, confirm the role of this hormone during short (minutes to hours)- and long-term (days to weeks) responses to stress. The role of membrane-initiated cortisol signaling during long-term responses has been recently explored. In this study, Sparus aurata were intraperitoneally injected with coconut oil alone or coconut oil containing cortisol, cortisol-BSA, or BSA. After 3 days of treatment, plasma, liver, and skeletal muscle were extracted. Plasma cortisol, as well as metabolic indicators in the plasma and tissues collected, and metabolism-related gene expression, were measured. Our results showed that artificially increased plasma cortisol levels in S. aurata enhanced plasma glucose and triacylglycerols values as well as hepatic substrate energy mobilization. Additionally, cortisol stimulated hepatic carbohydrates metabolism, as seen by the increased expression of metabolism-related genes. All of these responses, observed in cortisol-administered fish, were not detected by replicating the same protocol and instead using cortisol-BSA, which exclusively induces membrane-initiated effects. Therefore, we suggest that after three days of cortisol administration, only genomic actions are involved in the metabolic responses in S. aurata., This work was funded by Spanish Ministry of Science and Innovation—MICINN (PID2020-117557RB-C22) awarded to JMM; Fondo de Financiamiento de Centros de Investigación en Áreas Prioritarias (FONDAP) Grant INCAR 15110027; Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT) Grant 1201498 (to Juan Antonio Valdés), and ANID FONDECYT Postdoctorado [grant number 3210050] awarded to Jorge E. Aedo. The authors (I.R, G.M, and J.M.M) belong to the Fish Welfare and Stress Network (AGL2016-81808-REDT), supported by the Agencia Estatal de Investigación (MICINN, Spanish Government).

Evaluating the survival of discarded species is gaining momentum after the new European Common Fisheries Policy (Article 15 of the European Regulation No. 1380/2013). This regulation introduced a discard ban, with an exemption for those species with demonstrated high survival rates after their capture and release. Candidate species should be evaluated for each fishing gear and geographical area. In this study, we assessed not only survival, but also physiological recovery rates of blackspot seabream (Pagellus bogaraveo) below commercial size captured with a hookline called “voracera” in the Strait of Gibraltar (SW Atlantic waters of Europe). Experiments onboard a commercial fishing vessel were paralleled with studies in controlled ground-based facilities, where the capture process was mimicked, and physiological recovery markers were described. Our results confirmed that hookline capture induced acute stress responses in the target species, such as changes in plasma cortisol, lactate, glucose, and osmolality. However, 90.6% of the blackspot seabreams below commercial size captured with this fishing gear managed to survive, and evidenced physiological recovery responses 5 h after capture, with complete homeostatic recovery occurring within the first 24 h. Based on this study, the European Commission approved an exemption from the discard (EU Commission Delegated Regulation 6794/2018). Thus, the robust methodology described herein can be an important tool to mitigate the problem of discards in Europe.

Aging is the result of the deterioration of the homeostatic systems (nervous, endocrine, and immune systems), which preserve the organism’s health. We propose that the age-related impairment of these systems is due to the establishment of a chronic oxidative stress situation that leads to low-grade chronic inflammation throughout the immune system’s activity. It is known that the immune system weakens with age, which increases morbidity and mortality. In this context, we describe how the function of immune cells can be used as an indicator of the rate of aging of an individual. In addition to this passive role as a marker, we describe how the immune system can work as a driver of aging by amplifying the oxidative-inflammatory stress associated with aging (oxi-inflamm-aging) and inducing senescence in far tissue cells. Further supporting our theory, we discuss how certain lifestyle conditions (such as social environment, nutrition, or exercise) can have an impact on longevity by affecting the oxidative and inflammatory state of immune cells, regulating immunosenescence and its contribution to oxi-inflamm-aging.

Arachidonic acid (AA)-derived cytochrome P450 (CYP) derivatives, epoxyeicosatrienoic acids (EETs) and 20-hidroxyeicosatetranoic acid (20-HETE), play a key role in kidney tubular and vascular functions and blood pressure. Altered metabolism of CYP epoxygenases and CYP hydroxylases has differentially been involved in the pathogenesis of metabolic disease-associated vascular complications, although the mechanisms responsible for the vascular injury are unclear. The present study aimed to assess whether obesity-induced changes in CYP enzymes may contribute to oxidative stress and endothelial dysfunction in kidney preglomerular arteries. Endothelial function and reactive oxygen species (ROS) production were assessed in interlobar arteries of obese Zucker rats (OZR) and their lean counterparts lean Zucker rats (LZR) and the effects of CYP2C and CYP4A inhibitors sulfaphenazole and HET0016, respectively, were examined on the endothelium-dependent relaxations and O2.- and H2O2 levels of preglomerular arteries. Non-nitric oxide (NO) non-prostanoid endothelium-derived hyperpolarization (EDH)-type responses were preserved but resistant to the CYP epoxygenase blocker sulfaphenazole in OZR in contrast to those in LZR. Sulfaphenazole did not further inhibit reduced arterial H2O2 levels, and CYP2C11/CYP2C23 enzymes were downregulated in intrarenal arteries from OZR. Renal EDH-mediated relaxations were preserved in obese rats by the enhanced activity and expression of endothelial calcium-activated potassium channels (KCa). CYP4A blockade restored impaired NO-mediated dilatation and inhibited augmented O2.- production in kidney arteries from OZR. The current data demonstrate that both decreased endothelial CYP2C11/ CYP2C23-derived vasodilator H2O2 and augmented CYP4A-derived 20-HETE contribute to endothelial dysfunction and vascular oxidative stress in obesity. CYP4A inhibitors ameliorate arterial oxidative stress and restore endothelial function which suggests its therapeutic potential for the vascular complications of obesity-associated kidney injury.

Cytokine- and chemokine-mediated signalling is involved in the neuroinflammatory process that leads to retinal ganglion cell (RGC) damage in glaucoma. Substances with anti-inflammatory properties could decrease these cytokines and chemokines and thus prevent RGC death. The authors of this study analysed the anti-inflammatory effect of a hydrophilic saffron extract standardized to 3% crocin content, focusing on the regulation of cytokine and chemokine production, in a mouse model of unilateral laser-induced ocular hypertension (OHT). We demonstrated that following saffron treatment, most of the concentration of proinflammatory cytokines (IL-1β, IFN-γ, TNF-α, and IL-17), anti-inflammatory cytokines (IL-4 and IL-10), Brain-derived Neurotrophic Factor (BDNF), Vascular Endothelial Growth Factor (VEGF), and fractalkine were unaffected in response to laser-induced OHT in both the OHT eye and its contralateral eye. Only IL-6 levels were significantly increased in the OHT eye one day after laser induction compared with the control group. These results differed from those observed in animals subjected to unilateral OHT and not treated with saffron, where changes in cytokine levels occurred in both eyes. Therefore, saffron extract regulates the production of proinflammatory cytokines, VEGF, and fractalkine induced by increasing intraocular pressure (IOP), protecting the retina from inflammation. These results indicate that saffron could be beneficial in glaucoma by helping to reduce the inflammatory process.

Este artículo se encuentra disponible en la siguiente URL: https://www.sciencedirect.com/science/article/pii/S0032579119480139?via%3Dihub#! The aim of the present study is to assess the effect of the dietary free fatty acid (FFA) content and dietary fat saturation degree on the fatty-acid (FA) digestibility and lipid-class content along the gastrointestinal tract and excreta in broiler chickens. The 8 experimental diets resulted from replacing crude soybean oil with soybean acid oil from chemical refining, or crude palm oil with palm FA distillate from physical refining. Thus, there were 4 soybean and 4 palm diets with 6% added fat varying in their FFA% (5, 15, 35, and 50%). Samples of digestive content (gizzard, duodenum, jejunum, and ileum) and excreta were collected at 14 D for the determination of the FA digestibility and lipid-class content. The total FA digestibility coefficients reported for the chickens fed S diets in the jejunum, ileum, and excreta were higher than for those fed P diets (P ≤ 0.02). The general greater digestibility of the unsaturated diets was mainly explained by a higher contribution of the ileum to the absorption of saturated FA. The dietary FFA content mainly affected the FA absorption process. The diets with 50% FFA presented lower saturated FA digestibility coefficients in the jejunum and ileum (P ≤ 0.03), and higher content of FFA in the ileum and excreta (P ≤ 0.014), in comparison to the diets with 5% FFA. The 15% FFA diets were not different from the 5% FFA diets, regarding the saturated FA digestibility in the jejunum and excreta, and the FFA content in the ileum and excreta. It was concluded that unsaturated diets with moderate content of dietary FFA (up to 15%) could be used in broiler-chicken starter diets, as they led to similar FA absorption and performance results to the diets with the lowest dietary FFA content. From the present study, it has also been concluded that dietary saturated FA content has a greater impact on FA absorption than the dietary FFA content has.

Backgrond and purpose Obesity is a risk factor for the development of chronic kidney disease independent of diabetes, hypertension and other comorbidities. Obesity-associated nephropathy has been linked to dysregulation of the cell energy sensor AMP-activated protein kinase (AMPK). We aimed here to assess whether impairment of AMPK activity may cause renal arterial dysfunction in obesity and to evaluate the therapeutic potential of AMPK activation in the kidney. Experimental approach The effects of the AMPK activator A769662 were assessed on intrarenal arteries dissected out from ob/ob mice and obese Zucker rats kidney and then mounted in microvascular myographs. Superoxide and hydrogen peroxide production were measured by chemiluminescence and fluorescence, respectively, and protein expression was analyzed by Western blotting. Key results Endothelium-dependent vasodilation and PI3K/Akt/eNOS pathway were impaired in preglomerular arteries from genetically obese rats and mice, along with impaired arterial AMPK activity and blunted relaxations induced by the AMPK activator A769662. Acute ex vivo exposure to A769662 restored endothelial function and enhanced activity of PI3K/Akt/eNOS pathway in obese rats, while in vivo treatment with A769662 improved metabolic state and ameliorated endothelial dysfunction, reduced inflammatory markers and vascular oxidative stress in renal arteries and restored redox balance in renal cortex of obese mice. Conclusions and implications These results demonstrate that AMPK dysregulation underlies obesity-associated kidney vascular dysfunction and activation of AMPK improves metabolic state, protects renal endothelial function and exerts potent vascular antioxidant and anti-inflammatory effects. The beneficial effects of vascular AMPK activation might represent a promising therapeutic approach for the treatment of obesity-related- kidney injury.

An increased risk of cardiovascular morbidity has been reported in lithiasic patients. In this context, endothelial dysfunction (ED), an earlier status of atherogenesis, has been identified in hyperoxaluria rat models of urolithiasis. Objective: The purpose of this study was to determine the endothelial vascular function in patients with urolithiasis in relation to systemic inflammatory, oxidative stress, and vascular function serum markers. Methods: A cross-sectional study was performed between 27 urolithiasic patients, matched for age and sex, with 27 healthy patients. Endothelial function was assessed by measuring flow-mediated dilation (Celermajer method). Fasting blood was collected to determine metabolic parameters (glucose and lipid profile), along with serum CRP, IL-6, MDA, ADMA, and VCAM-1. Results: Both the control and urolithiasis groups were homogenous in anthropometric, exploration, and general laboratory measures. Flow-mediated dilation (%FMD) was 11.85% (SE: 2.78) lower in the lithiasis group (p < 0.001). No significant differences were achieved between groups when CRP, IL-6, MDA, ADMA, and VCAM-1 were compared, although slightly higher values of CRP, ADMA, and VCAM-1 were detected in the lithiasic group. A correlation was not reached in any of the serum markers when they were related to flow-mediated values, although a slight negative correlation trend was observed in MDA, VCAM-1, and IL-6 values. Conclusions: Endothelial dysfunction constitutes an important disorder related to urolithiasis patients. It must be considered as an early feature responsible for future cardiovascular events. Our study did not find a significant association between inflammatory, oxidative stress, endothelial serum markers, and flow-mediated dilation., Puerta de Hierro-Segovia de Arana Research Institute

The use of lysed microalgae in the diet of carnivorous fish can increase the bioavailability of proteins and bioactive compounds, such as unsaturated fatty acids or vitamins in the digestive tract. These are essential molecules for the proper physiological development of fish in aquaculture. However, some antinutritional components and other undesirable molecules can be released from an excess of microalgae supplied, compromising the integrity of the intestine. The inclusion of small amounts of hydrolized microalgae in the fish diet can be a good strategy to avoid negative effects, improving the availability of beneficial compounds. Nannochloropsis gaditana is an interesting microalgae as it contains nutraceuticals. Previous studies reported beneficial effects after its inclusion in the diet of Sparus aurata, a widely cultured species in Europe and in all Mediterranean countries. However, administration of raw microalgae can produce intestinal inflammation, increased intestinal permeability, bacterial translocation and disturbance of digestion and absorption processes. The aim of this study was to evaluate changes in the intestinal microbiota and barrier stability of S. aurata fed with low inclusion (5%) hydrolysed N. gaditana. Intestinal microbiota was analyzed using Illumina MiSeq technology and libraries were constructed using variable regions V3–V4 of 16S rDNA molecules. Analysis were based in the identification, quantification and comparison of sequences. The predictive intestinal microbial functionality was analyzed with PICRUSt software. The results determined that the intestinal microbiota bacterial composition and the predictive intestinal microbiota functionality did not change statistically after the inclusion of N. gaditana on the diet. The study of gene expression showed that genes involved in intestinal permeability and integrity were not altered in fish treated with the experimental diet. The potential functionality and bacterial taxonomic composition of the intestinal microbiota, and the expression of integrity and permeability genes in the intestine of the carnivorous fish S. aurata were not affected by the inclusion of hydrolysed 5% N. gaditana microalgae.

Vertebrates possess circadian clocks, driven by transcriptional–translational loops of clock genes, to orchestrate anticipatory physiological adaptations to cyclic environmental changes. This work aims to investigate how the absence of a light-dark cycle and a feeding schedule impacts the oscillators in the hypothalamus-pituitary-interrenal axis of goldfish. Fish were maintained under 12L:12D feeding at ZT 2, 12L:12D feeding at random times, and constant darkness feeding at ZT 2. After 30 days, fish were sampled to measure daily variations in plasma cortisol and clock gene expression in the hypothalamus-pituitary-interrenal (HPI) axis. Clock gene rhythms in the HPI were synchronic in the presence of a light-dark cycle but were lost in its absence, while in randomly fed fish, only the interrenal clock was disrupted. The highest cortisol levels were found in the randomly fed group, suggesting that uncertainty of food availability could be as stressful as the absence of a light-dark cycle. Cortisol daily rhythms seem to depend on central clocks, as a disruption in the adrenal clock did not impede rhythmic cortisol release, although it could sensitize the tissue to stress.

263 p. (cast) 144 p. (eusk) Se ha analizado la variabilidad de la composición bioquímica de la anchoa del Golfo de Bizkaia durante su desarrollo y reproducción. El análisis de la composición bioquímica nos ha permitido observar los cambios en el patrón de asignación de los componentes bioquímicos a los diferentes órganos. El patrón de asignación ha mostrado diferencias estacionales, diferencias que tienden a ser más notables a medida que el individuo crece y alcanza la madurez sexual. Así, mientras que los individuos que se encontraban en las primeras etapas del desarrollo debían decidir si invertir su excedente energético en crecimiento somático (para escapar de los depredadores) o bien invertir en acumulación de reservas energéticas (para superar períodos de balance energético negativo, por ejemplo durante el invierno), los individuos adultos debían decidir cuándo y cuánta energía invertir en la reproducción, porque dicha inversión tenía que darse a expensas del crecimiento somático y/o del almacenamiento de energía.Por otra parte, determinar las diferencias interanuales nos ha permitido, en primer lugar, estudiar si la composición bioquímica influía en la mortalidad invernal de los juveniles; en segundo lugar, estudiar si había diferencias interanuales en la translocación de componentes bioquímicos para la reproducción, y, finalmente, determinar si existían diferencias de fecundidad entre las dos zonas de puesta más importantes del Golfo de Bizkaia (Adur y Garona).

263 p. (cast) 144 p. (eusk) Se ha analizado la variabilidad de la composición bioquímica de la anchoa del Golfo de Bizkaia durante su desarrollo y reproducción. El análisis de la composición bioquímica nos ha permitido observar los cambios en el patrón de asignación de los componentes bioquímicos a los diferentes órganos. El patrón de asignación ha mostrado diferencias estacionales, diferencias que tienden a ser más notables a medida que el individuo crece y alcanza la madurez sexual. Así, mientras que los individuos que se encontraban en las primeras etapas del desarrollo debían decidir si invertir su excedente energético en crecimiento somático (para escapar de los depredadores) o bien invertir en acumulación de reservas energéticas (para superar períodos de balance energético negativo, por ejemplo durante el invierno), los individuos adultos debían decidir cuándo y cuánta energía invertir en la reproducción, porque dicha inversión tenía que darse a expensas del crecimiento somático y/o del almacenamiento de energía.Por otra parte, determinar las diferencias interanuales nos ha permitido, en primer lugar, estudiar si la composición bioquímica influía en la mortalidad invernal de los juveniles; en segundo lugar, estudiar si había diferencias interanuales en la translocación de componentes bioquímicos para la reproducción, y, finalmente, determinar si existían diferencias de fecundidad entre las dos zonas de puesta más importantes del Golfo de Bizkaia (Adur y Garona).

[ES]: El objetivo de esta tesis era establecer si el uso de vertederos como fuente de alimento por las cigüeñas blancas, el cual a priori es beneficioso, tal y como demuestra el aumento en la población, podría tener efectos en la salud de los pollos. Con este propósito, evaluamos el estado de individuos alimentados con distintas proporciones de comida proveniente de vertederos, utilizando una aproximación múltiple basada en la evaluación del estado nutricional, de la funcionalidad hepática y renal, del balance del estrés oxidativo y de la presencia de patógenos. Así, pudimos identificar que, según aumentaba la proporción de comida proveniente de vertederos, mejor era el estado nutricional de los pollos, lo que indicaba una mayor ingesta de comida. Además, no encontramos efectos negativos en el organismo, al no verse afectada ni la función hepática ni la renal. El balance del estrés oxidativo, mucho más sensible al daño por los posibles contaminantes de los vertederos, muestra los primeros pasos de una respuesta hormética; aumento de las defensas por un daño, pero sin comprometer al organismo. Finalmente, la presencia de E. coli resistente a antibióticos es mayor en individuos que utilizan vertederos, lo cual puede ser un problema no solo para su propia salud, sino también por la transmisión a otros los animales de vida libre, al ganado y a humanos. Tras obtener una visión amplia de los efectos de este uso, tratamos de confirmar los resultados previos a mayor escala, aumentando el número de colonias de estudio, y verificando si los efectos se mantienen independientemente del año. En el segundo capítulo confirmamos que los beneficios en el estado nutricional en los pollos que se alimentan en vertedero son constantes entre años, así como la falta de afectación hepática o renal. Sin embargo, la respuesta del balance del estrés oxidativo varia, debido a la importancia de los antioxidantes en la dieta y la necesidad de comida natural durante los primeros días de. Sin embargo, el uso de este tipo de alimento nunca produce alteraciones en el balance del estrés oxidativo, lo que indica que, sin importar el año, el daño potencial está siendo contrarrestado. Para facilitar el seguimiento de estas colonias en el futuro es necesario encontrar alguna medida externa que varíe en relación con el uso de vertederos, reduciendo la manipulación y el coste. Encontramos que tanto la condición corporal como el color rojo de las patas se han visto afectadas por el uso de vertederos, pero en sentido opuesto, ya que la condición corporal aumenta con el uso, debido a la mayor cantidad de comida, pero el color rojo de las patas disminuye, debido a la menor cantidad de carotenoides. Los resultados previos revelaron el beneficio a corto plazo del uso de los vertederos. Sin embargo, desconocemos los posibles efectos a largo plazo, ya que las condiciones durante el desarrollo pueden influir en rasgos que aparecen más tarde en la vida. Como el control de estos individuos durante toda su vida es prácticamente imposible, como aproximación a este efecto hemos elegido el estudio de los telómeros. A los telómeros se les señala como responsables de unir las condiciones durante la juventud y la esperanza de vida potencial, y cuya tasa de acortamiento puede verse alterada por factores externos que actúan a través del balance del estrés oxidativo. Nuestros resultados muestran que la administración de antioxidantes en individuos de vida libre hace que mantengan sus telómeros más largos, sugiriendo la posibilidad de que estos individuos padezcan una falta de antioxidantes en su dieta, lo que podría afectar a su esperanza de vida. El uso de aproximaciones multidisciplinares al estudio del estado de determinadas especies, como es el caso de la cigüeña blanca, se está haciendo cada vez más necesario, debido principalmente a la progresiva globalización, lo que conllevará un mayor número de interacciones entre distintas especies y el ser humano., [EN]: This PhD thesis aimed to establish if the use of landfills as a food resource by white storks, which a priori, judged by the increasing population appears positive, could have any effects on the health status of nestlings. For this purpose, initially, we evaluated the status of individuals which were fed different proportions of food from landfills, using a multidisciplinary approach based on the evaluation of nutritional status, liver and renal function, oxidative stress balance and the presence of pathogens. This way we identified that, in fact, the higher the proportion of food from landfills the better the nutritional status, indicating higher food intake. Hepatic and/or renal function were not affected. Also, oxidative stress balance, which is more sensitive to damage by the potentially present pollutants in the landfill, is suggestive of a hormetic response; i. e. an increase in defences that allows to cope with limited damage without compromising the organism. Landfill foraging storks also have a higher prevalence of antibiotic resistant E.coli, which could be a problem not only for the health of the storks, also for the transmission of these microorganisms to other wildlife, livestock and humans. After obtaining a broad overview of the effect of this use, we tried to confirm previous results at a much larger scale, increasing the number of colonies of study, and more importantly, to verify if the benefits hold, regardless of the year of study. In the second chapter, we confirmed that the benefits on nutritional status of nestlings which were fed with food from landfills are constant between years, as well as the apparent lack of affectation on hepatic and/or renal systems. However, the response of the oxidative stress balance was not always the same, because of dietary antioxidants and the necessity of natural food during the first period of life. Even so, the use of landfill oraged food never produced a disbalance in the oxidative stress balance, which indicates that, despite the year, the potential damage could be perfectly counteracted by the organisms of the nestlings. To make the monitoring of these colonies in the future easier it is necessary to find some external measures which could be related to the use of landfills, making the collection of data less invasive and less challenging in terms of cost and time. We found that both body condition and the redness of legs are affected by the use of landfills but with an opposite trend, as body condition increases with the use, due to the higher amount of food, redness of legs decreases, by the lower amount of carotenoids, responsible of the redness. These results could be useful to continue the monitoring of the studied colonies with less expenditure of resources, time, and money. These results revealed at least the short-term benefits of the use of landfills as a food resource. However, we did not know if this behaviour would have carry-over effects, as early-development conditions can influence different life-history traits later in life. As the monitoring of these individuals during their entire life is practically impossible, as a proxy to this effect we chose to measure telomeres, as their length has been suggested to be responsible for the link between early-life conditions and potential lifespan, and because their rate of attrition could be altered by external factors which act through oxidative stress balance. We approached this question experimentally, and our results, showed that the administration of antioxidants in free-living individuals maintains telomeres longer, suggesting that possibly these individuals suffer a lack of dietary antioxidants, which in turn could affect their potential lifespan. The use of these multidisciplinary approaches to the study of the status of certain species, such as the white stork, is becoming increasingly necessary. This is mainly due to progressive globalization, which will lead to a greater number of interactions between different species and humans., Javier Pineda Pampliega ha sido beneficiario de un contrato predoctoral dentro del programa “Formación de personal investigador. Contratos predoctorales Complutense. Convocatoria 2015. CT45/15-CT46/15”.

Urbanization constitutes one of the major transformations of natural habitats, creating new areas characterized by multiple potential wildlife stressors. Birds that live in highly anthropized zones are confronted with physiological and behavioural challenges caused by these stressors. Here, we investigated if several health parameters differed between three subpopulations of tree sparrow nestlings subjected to different levels of anthropogenic pollution, and particularly noise pollution: a quiet rural area, a noisy rural area adjacent to an airport and a heavily urbanized area. We compared body condition, oxidative stress markers and baseline corticosterone levels, expecting urban nestlings to be in overall worse condition as compared to rural (rural and rural airport) birds. In addition, we expected nestlings exposed to aircraft noise to show intermediate stress levels. We found that rural-airport nestlings had the highest levels of antioxidant capacity of plasma and did not differ from rural counterparts in the rest of the parameters. By contrast, urban nestlings were in slightly worse body condition and had lower antioxidant capacity than rural and rural-airport individuals. Our results suggest that aircraft noise does not constitute a significant stressor for nestlings. In contrast, urban conditions constitute a more challenging situation, negatively impacting different physiological systems. Although nestlings seem able to buffer these challenges in the short-term, further research should explore the long-term potential consequences of early exposure to these conditions., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported by a research grant from the Spanish Ministerio de Economía y Competitividad (CGL2014-55577-R) to DG. LP-R was supported by a postdoctoral contract for accessing the Spanish System of Science, Technology, and Innovation (SECTI) from the University of Castilla-La Mancha. IR was supported by a Formación de Personal Universitario (FPU) grant from the Spanish Ministry of Culture and Education. JM was supported by a postdoctoral grant from the Juan de la Cierva Subprogram (FJCI-2017–34109), with the financial sponsorship of the MICINN. JIA work is a contribution to project CGL2017-85637-P of the Spanish Ministry of Economy and Competitiveness.

Este artículo se encuentra disponible en la siguiente URL: https://www.sciencedirect.com/science/article/pii/S0032579121002959?via%3Dihub The aim of the present study is to assess the effect of the free-fatty-acid (FFA) content and saturation degree of dietary fat (added at 6%) on the fattyacid (FA) digestibility and lipid-class content along the gastrointestinal tract and excreta in broilers from 22 to 37 d of age. This is essential to determine the potential use of acid oils (refining by-products rich in FFA) in broiler diets as an alternative to crude oils. The study consisted of a 2 £ 4 factorial arrangement, which included 2 fat sources (soybean oils − unsaturated, or palm oils − saturated) and 4 levels of FFA (5, 15, 35, and 50%). Samples of digestive content of the gizzard, duodenum, jejunum, ileum and of the excreta were obtained at 37 d of age. Irrespective of the dietary fat source, more than 80% of total FA (TFA) was absorbed in the jejunum. Broilers fed with unsaturated diets had a higher absorption efficiency of FA than did those fed with saturated diets. This conclusion is supported by the lower FFA content and the higher TFA and polyunsaturated FA (PUFA) digestibility coefficients in the ileum (P < 0.001) observed in the former group. The dietary FFA level did not affect the FA absorption process as much as the dietary fat source did. This was supported by the lack of statistical differences among the diets with a similar saturation degree but rather different levels of FFA, for TFA, saturated FA, and PUFA digestibility coefficients both in the jejunum and ileum. However, the interactions reported in the ileum for triacylglycerol and diacylglycerol contents (P < 0.001), as well as for monounsaturated FA digestibility coefficients (P < 0.05) show that the dietary FFA content affects the FA absorption process. The present results show that the inclusion of acid oils in grower-finisher broiler diets with FFA levels up to 35% does not have a negative impact on the FA absorption process.

[EN] Short-legged, small, robust frogs of the family Craugastoridae present a remarkable beta-diversity in the high Andes, their distributions being characterized by a very high degree of micro-endemism to specific valleys. We used dataloggers to study the temperature and humidity conditions of microhabitats of several species of the genus Microkayla at three elevation belts: Below, within, and above the altitudinal range of their distribution in Bolivia. We also conducted thermal physiology experiments on a limited number of individuals of one of these species. Our aim was to infer on factors that may limit the distribution of anurans in a biological hotspot that is threatened by climate warming. We found an unexpected thermal heterogeneity within the slopes at three different Andean valleys that explained the specific distribution of species of Microkayla at each site. Species distribution was associated to elevation belts with the highest ambient relative humidity, and there was high variability in thermal preference when individuals were experimentally exposed to a thermal gradient. Critical thermal maxima compared to the temperatures that frogs confront in nature, as well as thermal performance trials, revealed that the studied species has a broad physiological tolerance to temperature. These results point to moisture, and not temperature, as the limiting climatic factor determining the occurrence of these species in high Andean slopes, but further experimental work on water balance is needed. The predicted desertification of the Andes in future climate change scenarios poses a potentially serious threat to this highly diverse group of amphibians., [ES] Las pequeñas ranas robustas y de patas cortas de la familia Craugastoridae presentan una alta diversidad beta en la región altoandina, donde la distribución de las distintas especies se caracteriza por un alto grado de endemismo, restringiéndose a valles concretos. Utilizamos “dataloggers” para estudiar las condiciones de temperatura y humedad en los microhábitats de algunas especies de Microkayla en tres franjas a distinta elevación: por debajo de su rango altitudinal de distribución, dentro de dicho rango, y por encima. Además, realizamos experimentos de fisiología térmica con un limitado número de ejemplares de una especie de Microkayla. Nuestro objetivo era averiguar los factores que pueden limitar la distribución de los anuros en un punto caliente de biodiversidad amenazado por el calentamiento climático. Encontramos una sorprendente heterogeneidad térmica en las laderas de tres valles andinos diferentes, que explican la distribución de las especies de Microkayla en cada sitio. La distribución de las especies está asociada a las franjas altitudinales de humedad ambiental más alta, y se observa una alta variabilidad en las preferencias térmicas cuando los individuos son sometidos experimentalmente a gradientes de temperatura. Las temperaturas críticas máximas, comparadas con las temperaturas que las ranas confrontan en la naturaleza, así como los experimentos de desempeño térmico realizados, revelan que la especie estudiada tiene una amplia tolerancia térmica. Estos resultados apuntan a la humedad, y no la temperatura, como el factor climático limitante que determina la existencia de estas especies en las laderas altoandinas, aunque se necesita más trabajo experimental en balance hídrico para comprobar esto. La previsible desertificación de los Andes bajo escenarios de cambio climático futuros, supone por tanto una seria amenaza potencial para este grupo tan diverso de anfibios., This research was supported by Project CG2014-56160-P of the Spanish Government.

Resumen: El objetivo de este trabajo fue comparar el rendimiento de los estudiantes que ingresaron en 2014, 2015 y 2016, y cursaron Fisiología en el tercer semestre. Para la aprobación de los cursos, 2015 solamente se exigía la asistencia a prácticos (1er y 2do año); en 2016 la asistencia a prácticos en 1er año, y evaluación por parciales en 2do año; en 2017 la evaluación por parciales (1er y 2do año). La proporción de estudiantes que aprobó el curso disminuyó de 2015 a 2016 (P

Temperature is an important abiotic factor that drives the evolution of ectotherms owing to its pervasive effects at all levels of organization. Although a species’ thermal tolerance is environmentally driven within a spatial cline, it may be constrained over time due to differential phylogenetic inheritance. At the limits of thermal tolerance, hemolymph oxygen is reduced and lactate formation is increased due to mismatch between oxygen supply and demand; imbalance between enzyme flexibility/stability also impairs the ability to generate energy. Here, we characterized the effects of lower (LL50) and upper (UL50) critical thermal limits on selected descriptors of aerobic and anaerobic metabolism in 12 intertidal crab species distributed from northern Brazil (≈7.8°S) to southern Patagonia (≈53.2°S), considering their phylogeny. We tested for (i) functional trade-offs regarding aerobic and anaerobic metabolism and LDH kinetics in shaping thermal tolerance; (ii) influence of shared ancestry and thermal province on metabolic evolution; and (iii) presence of evolutionary convergences and adaptive peaks in the crab phylogeny. The tropical and subtropical species showed similar systemic and kinetic responses, both differing from the sub-Antarctic crabs. The lower UL50’s of the sub-Antarctic crabs may reflect mismatch between the evolution of aerobic and anaerobic metabolism since these crabs exhibit lower oxygen consumption but higher lactate formation than tropical and subtropical species also at their respective UL50’s. LDH activity increased with temperature increase, while KmPyr remained fairly constant; catalytic coefficient correlated negatively with thermal niche. Thermal tolerance may rely on a putative evolutionary trade-off between aerobic and anaerobic metabolism regarding energy supply, while temperature compensation of kinetic performance is driven by thermal habitat as revealed by the LDH affinity/efficiency equilibrium. The overall physiological evolution revealed two homoplastic adaptive peaks in the sub-Antarctic crabs with a further shift in the tropical/subtropical clade. The physiological traits at UL50 have evolved in a phylogenetic manner while all others were more plastic. Thus, shared inheritance and thermal environment have driven the crabs’ thermal tolerance and metabolic evolution, revealing physiological transformations that have arisen in both colder and warmer climes, especially at higher levels of biological organization and phylogenetic diversity. Fil: Coelho Faria, Samuel. Universidade de Sao Paulo; Brasil Fil: Bianchini, Adalto. Universidade Federal Do Rio Grande.; Brasil Fil: Machado Lauer, Mariana. Universidade Federal Do Rio Grande.; Brasil Fil: Ribeiro Latorre Zimbardi, Ana Lúcia. Universidade de Sao Paulo; Brasil Fil: Tapella, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Romero, Maria Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Campbell McNamara, John. Universidade de Sao Paulo; Brasil

“Generalmente los machos en las especies con reproducción sexual son menos selectivos y más persuasivos que las hembras durante el cortejo que precede al apareamiento. Esto se debe a que en la mayoría de los casos el potencial reproductivo de los machos es más grande que el de las hembras. Sin embargo, los machos podrían estar motivados a ser selectivos, en parte porque durante el cortejo invierten energía y tiempo, recursos que podrían dirigir a otras actividades como la evasión de depredadores. Observaciones preliminares sugieren que tal selectividad podría estar ocurriendo en Xenotoca variata (un pez dulceacuícola endémico de México), ya que los machos parecen acercarse (posiblemente cortejar) diferencialmente a las hembras. Por lo tanto, propuse realizar una serie de experimentos para confirmar y explicar por qué podría ocurrir la selectividad masculina en los peces Xenotoca variata.”

La intervención de los seres humanos en los procesos de cría y recría en animales de producción pueden tener diferente impacto en virtud al tipo, momento y duración de la misma. El objetivo del trabajo fue evaluar si existen cambios en parámetros fisiológicos, sanguíneos y de comportamiento en cabritos Saanen en función al tipo de crianza, 10 criados con sus madres (CT) vs. 10 criados artificialmente (CA), en las etapas de lactante y recría. Semanalmente se midió: frecuencia cardiaca (FC), temperatura rectal (TR), frecuencia respiratoria (FR), predisposición a ser atrapado y actitud de patear. Previo se tomaron 10 ml de sangre para realización del leucograma. El diseño experimental fue el de mediciones repetidas en el tiempo. Los datos fueron analizados a través del programa InfoStat. Ni entre periodos ni entre tratamientos se detectaron diferencias significativas para FC como TR. En ambos periodos a los animales del CT resultó más difícil atraparlos (lactante: p