Beak colour dynamically signals changes in fasting status and parasite loads in king penguins

This research was funded by the French Polar Institute (IPEV–Research Program 119) and the French National Centre for Scientific Research (CNRS-INEE). Field logistic support was provided by Terres Australes et Antarctiques Françaises. Q.S. was funded by a doctoral fellowship from the Ministère Français de l’Education Supérieur et de la Recherche. We thank all over-wintering assistants: Benoit Gineste, Sylvia Pardonnet, Laureline Durand, Emilie Lefol and Hédi Saadaoui for field work and Emilio Rojas for helpful discussion on the analyses. We apologize to our stick insect (Carausius morosus) for bearing with VAV’s inquisitive curiosity during our debates on color ornaments in king penguins. We sincerely thank the editor and 2 anonymous reviewers for their helpful comments on a previous version of the paper.Peer reviewedPostprin

The oxidative debt of fasting : evidence for short to medium-term costs of advanced fasting in adult king penguins

This research was funded by the French Polar Institute (IPEV–Research Program 119) and the French National Centre for Scientific Research (CNRS-INEE). We are especially grateful to Dominic L. Cram and one anonymous reviewer for helpful comments on the paper. Field logistic support was provided by Terres Australes et Antarctiques Françaises. QS was funded by a doctoral fellowship from the Ministère Français de l’Education Supérieur et de la Recherche.Peer reviewedPublisher PD

Experimental stress during molt suggests the evolution of condition-dependent and condition-independent ornaments in the king penguin

Acknowledgments We thank Emilie Lefol for her help in the field, and two anonymous reviewers for their comments on the manuscript. This research was funded by the French Polar Institute (IPEV– Research Program 119) and the French National Centre for Scientific Research (CNRS- INEE). Field logistic support was provided by Terres Australes et Antarctiques Françaises. Q.S. was funded by a doctoral fellowship from the Ministère Français de l’Education Supérieur et de la Recherche.Peer reviewedPublisher PD

Oxidative stress and mitochondrial responses to stress exposure suggest that king penguins are naturally equipped to resist stress

We are grateful to four anonymous reviewers for their help in improving a previous draft of this manuscript and to the French Polar Institut (IPEV) for providing logistical support for this study through the programs 119 & 131. AS was self-funded during fieldwork, funded by the University of Angers during laboratory analyses, and was supported by a Marie Sklodowska-Curie Postdoctoral Fellowship (#658085) and a ‘Turku Collegium for Science and Medicine' Fellowship at the time of writing.Peer reviewedPublisher PD

Foster rather than biological parental telomere length predicts offspring survival and telomere length in king penguins

ACKNOWLEDGMENTS We are grateful to the field assistants who helped us with data collection in 2012-2013. This research was supported by the French Polar Research Institute (IPEV; program 119 ECONERGY), by the Centre National de la Recherche Scientifique (CNRS), by an International Emerging Action Grant (IEA n°203036) from the CNRS, and by the AXA Research Fund (post-doctoral fellowship to VA Viblanc). We are grateful to S Rogers and 5 anonymous reviewers for constructive and useful comments on previous drafts of the paper. DATA ACCESSIBILITY The data associated with this manuscript are available online at figshare doi: 10.6084/m9.figshare.12249902 (Viblanc et al. 2020).Peer reviewedPostprin

Nephron-Specific Deletion of Circadian Clock Gene Bmal1 Alters the Plasma and Renal Metabolome and Impairs Drug Disposition.

The circadian clock controls a wide variety of metabolic and homeostatic processes in a number of tissues, including the kidney. However, the role of the renal circadian clocks remains largely unknown. To address this question, we performed a combined functional, transcriptomic, and metabolomic analysis in mice with inducible conditional knockout (cKO) of BMAL1, which is critically involved in the circadian clock system, in renal tubular cells (Bmal1(lox/lox)/Pax8-rtTA/LC1 mice). Induction of cKO in adult mice did not produce obvious abnormalities in renal sodium, potassium, or water handling. Deep sequencing of the renal transcriptome revealed significant changes in the expression of genes related to metabolic pathways and organic anion transport in cKO mice compared with control littermates. Furthermore, kidneys from cKO mice exhibited a significant decrease in the NAD(+)-to-NADH ratio, which reflects the oxidative phosphorylation-to-glycolysis ratio and/or the status of mitochondrial function. Metabolome profiling showed significant changes in plasma levels of amino acids, biogenic amines, acylcarnitines, and lipids. In-depth analysis of two selected pathways revealed a significant increase in plasma urea level correlating with increased renal Arginase II activity, hyperargininemia, and increased kidney arginine content as well as a significant increase in plasma creatinine concentration and a reduced capacity of the kidney to secrete anionic drugs (furosemide) paralleled by an approximate 80% decrease in the expression level of organic anion transporter 3 (SLC22a8). Collectively, these results indicate that the renal circadian clocks control a variety of metabolic/homeostatic processes at the intrarenal and systemic levels and are involved in drug disposition

Foster rather than biological parental telomere length predicts offspring survival and telomere length in king penguins

Because telomere length and dynamics relate to individual growth, reproductive investment and survival, telomeres have emerged as possible markers of individual quality. Here, we tested the hypothesis that, in species with parental care, parental telomere length can be a marker of parental quality that predicts offspring phenotype and survival. In king penguins (Aptenodytes patagonicus), we experimentally swapped the single egg of 66 breeding pairs just after egg laying to disentangle the contribution of prelaying parental quality (e.g., genetics, investment in the egg) and/or postlaying parental quality (e.g., incubation, postnatal feeding rate) on offspring growth, telomere length and survival. Parental quality was estimated through the joint effects of biological and foster parent telomere length on offspring traits, both soon after hatching (day 10) and at the end of the prewinter growth period (day 105). We expected that offspring traits would be mostly related to the telomere lengths (i.e., quality) of biological parents at day 10 and to the telomere lengths of foster parents at day 105. Results show that chick survival up to 10 days was negatively related to biological fathers' telomere length, whereas survival up to 105 days was positively related to foster fathers' telomere lengths. Chick growth was not related to either biological or foster parents' telomere length. Chick telomere length was positively related to foster mothers' telomere length at both 10 and 105 days. Overall, our study shows that, in a species with biparental care, parents' telomere length is foremost a proxy of postlaying parental care quality, supporting the "telomere - parental quality hypothesis.

Food supplements increase adult tarsus length, but not growth rate, in an island population of house sparrows (Passer domesticus)

<p>Abstract</p> <p>Background</p> <p>Variation in food supply during early development can influence growth rate and body size in many species. However, whilst the detrimental effects of food restriction have often been studied in natural populations, how young individuals respond to an artificial increase in food supply is rarely investigated. Here, we investigated both the short-term and long-term effects of providing house sparrow chicks with food supplements during a key period of growth and development and assessed whether providing food supplements had any persistent effect upon adult size (measured here as tarsus length).</p> <p>Results</p> <p>Male nestlings tended to reach higher mass asymptotes than females. Furthermore, brood size was negatively associated with a chick's asymptotic mass. However, providing food supplements had no influence upon the growth rate or the asymptotic mass of chicks. Adults that received food supplements as chicks were larger, in terms of their tarsus length, than adults that did not receive extra food as chicks. In addition, the variation in tarsus length amongst adult males that were given food supplements as chicks was significantly less than the variance observed amongst males that did not receive food supplements.</p> <p>Conclusions</p> <p>Our results demonstrate that the food supply chicks experience during a critical developmental period can have a permanent effect upon their adult phenotype. Furthermore, providing extra food to chicks resulted in sex-biased variance in a size-related trait amongst adults, which shows that the degree of sexual size dimorphism can be affected by the environment experienced during growth.</p