Jumping performance in the highly aquatic frog, Xenopus tropicalis : sex-specific relationships between morphology and performance

Frogs are characterized by a morphology that has been suggested to be related to their unique jumping specialization. Yet, the functional demands associated with jumping and swimming may not be that different as suggested by studies with semi-aquatic frogs. Here, we explore whether features previously identified as indicative of good burst swimming performance also predict jumping performance in a highly aquatic frog, Xenopus tropicalis. Moreover, we test whether the morphological determinants of jumping performance are similar in the two sexes and whether jumping performance differs in the two sexes. Finally we test whether jumping capacity is positively associated with burst swimming and terrestrial endurance capacity in both sexes. Our results show sex-specific differences in jumping performance when correcting for differences in body size. Moreover, the features determining jumping performance are different in the two sexes. Finally, the relationships between different performance traits are sex-dependent as well with females, but not males, showing a trade-off between peak jumping force and the time jumped to exhaustion. This suggests that different selective pressures operate on the two sexes, with females being subjected to constraints on locomotion due to their greater body mass and investment in reproductive capacity. In contrast, males appear to invest more in locomotor capacity giving them higher performance for a given body size compared to females

htsint: a Python library for sequencing pipelines that combines data through gene set generation

Background: Sequencing technologies provide a wealth of details in terms of genes, expression, splice variants, polymorphisms, and other features. A standard for sequencing analysis pipelines is to put genomic or transcriptomic features into a context of known functional information, but the relationships between ontology terms are often ignored. For RNA-Seq, considering genes and their genetic variants at the group level enables a convenient way to both integrate annotation data and detect small coordinated changes between experimental conditions, a known caveat of gene level analyses. Results: We introduce the high throughput data integration tool, htsint, as an extension to the commonly used gene set enrichment frameworks. The central aim of htsint is to compile annotation information from one or more taxa in order to calculate functional distances among all genes in a specified gene space. Spectral clustering is then used to partition the genes, thereby generating functional modules. The gene space can range from a targeted list of genes, like a specific pathway, all the way to an ensemble of genomes. Given a collection of gene sets and a count matrix of transcriptomic features (e.g. expression, polymorphisms), the gene sets produced by htsint can be tested for 'enrichment' or conditional differences using one of a number of commonly available packages. Conclusion: The database and bundled tools to generate functional modules were designed with sequencing pipelines in mind, but the toolkit nature of htsint allows it to also be used in other areas of genomics. The software is freely available as a Python library through GitHub at https://github.com/ajrichards/htsint

Les hospitaliers de Rhodes au regard de leur voeu de pauvreté au XVe siècle (1420-1480)

Tous les frères de l’Ordre de l’Hôpital prononçaient lors de leur admission les trois vœux de pauvreté personnelle, de chasteté et d’obéissance à leur Maître. La règle de l’Hôpital (circa 1120) et d’autres premiers statuts interdisaient aux frères de vivre avec des biens propres et leur ordonnaient de vivre dans un dépouillement semblable à celui des membres d’autres ordres réguliers établis aux XIIe et XIIIe siècles. Le but de cette étude est d’examiner les règles existantes en la matière puis de voir dans quelle mesure les Hospitaliers résidant au couvent de Rhodes au XVe siècle étaient fidèles à leur vœu de pauvreté. À cette époque, Rhodes était le siège du gouvernement central de l’Ordre sous la conduite du Maître mais également un bastion militaire, face aux Mamelouks de l’Égypte et aux Turcs Ottomans alors en plein essor conquérant. Entre trois cent et cinq cent frères étaient réunis pendant de longues périodes de séjour au couvent pour résister à toutes attaques. Nous passerons en revue les prescriptions et pratiques qui gouvernaient cette originale communauté religieuse et militaire. Comme pour la plupart des autres ordres religieux réguliers, la pratique de la pauvreté personnelle s’était profondément altérée par rapport aux premiers temps de l’Hôpital. Les Hospitaliers, à Rhodes comme dans leurs commanderies occidentales, étaient autorisés à accéder à la propriété personnelle, sous des formes diverses bien qu’avec des limites. Leur vie au couvent était loin d’être ascétique mais à leur mort, leurs biens revenaient à l’Ordre

The Hospitallers of Rhodes and their Vow of Poverty in the 15th Century (1420-1480)

All brethren of the Order of the Hospital took the three monastic vows when they were admitted to the Order: personal poverty, chastity and obedience to their Master. The rule of the Hospital (circa 1120) and further early statutes forbade the brethren to hold private property and ordered them to live in the same state of poverty as the members of other regular orders established in the twelfth and thirteenth centuries. The purpose of this study, after examining the regulations in this respect, is to investigate to what extent the Hospitallers residing at the convent of Rhodes in the fifteenth century were faithful to their vow. At this period Rhodes was the head of the central government of the Order, under its Master, as well as a military stronghold in the Eastern Mediterranean, in face of the Mamluks of Egypt and the rapidly expanding Ottoman Turks. Three to five hundred brethren gathered for long periods of stay at the convent in order to resist any attack. We shall review in detail the ordinances and practices which ruled over this original religious as well as military community. As with most other regular religious orders, the practice of personal poverty had been deeply modified in comparison with the first times. The Hospitallers, at Rhodes as well as in their Western commanderies, were allowed to hold various forms of private property although within certain limits and their life at the convent was far from being ascetic However after death their property was recovered by the Order

Immune responses of wild birds to emerging infectious diseases

Over the past several decades, outbreaks of emerging infectious diseases (EIDs) in wild birds have attracted worldwide media attention, either because of their extreme virulence or because of alarming spillovers into agricultural animals or humans. The pathogens involved have been found to infect a variety of bird hosts ranging from relatively few species (e.g. Trichomonas gallinae) to hundreds of species (e.g. West Nile Virus). Here we review and contrast the immune responses that wild birds are able to mount against these novel pathogens. We discuss the extent to which these responses are associated with reduced clinical symptoms, pathogen load and mortality, or conversely, how they can be linked to worsened pathology and reduced survival. We then investigate how immune responses to EIDs can evolve over time in response to pathogen-driven selection using the illustrative case study of the epizootic outbreak of Mycoplasma gallisepticum in wild North American house finches (Haemorhous mexicanus). We highlight the need for future work to take advantage of the substantial inter- and intraspecific variation in disease progression and outcome following infections with EID to elucidate the extent to which immune responses confer increased resistance through pathogen clearance or may instead heighten pathogenesis.Auburn UniversityNatural Environment Research Council grant (NERC

Emerging pathogen evolution: Using evolutionary theory to understand the fate of novel infectious pathogens.

This is the final version. Available from Wiley / EMBO Press via the DOI in this record. Evolutionary biology is key to potentially predicting virulence and transmission after a pathogen jumps into a new host species. This knowledge would be valuable for designing public health strategies.Wellcome Trus

Immune-challenged fish up-regulate their metabolic scope to support locomotion

ArticleEnergy-based trade-offs occur when investment in one fitness-related trait diverts energy away from other traits. The extent to which such trade-offs are shaped by limits on the rate of conversion of energy ingested in food (e.g. carbohydrates) into chemical energy (ATP) by oxidative metabolism rather than by the amount of food ingested in the first place is, however, unclear. Here we tested whether the ATP required for mounting an immune response will lead to a trade-off with ATP available for physical activity in mosquitofish (Gambusia holbrooki). To this end, we challenged fish either with lipopolysaccharide (LPS) from E. coli or with Sheep Red Blood Cells (SRBC), and measured oxygen consumption at rest and during swimming at maximum speed 24h, 48h and 7 days post-challenge in order to estimate metabolic rates. Relative to saline-injected controls, only LPS-injected fish showed a significantly greater resting metabolic rate two days post-challenge and significantly higher maximal metabolic rates two and seven days post-challenge. This resulted in a significantly greater metabolic scope two days post-challenge, with LPS-fish transiently overcompensating by increasing maximal ATP production more than would be required for swimming in the absence of an immune challenge. LPS-challenged fish therefore increased their production of ATP to compensate physiologically for the energetic requirements of immune functioning. This response would avoid ATP shortages and allow fish to engage in an aerobically-challenging activity (swimming) even when simultaneously mounting an immune response. Nevertheless, relative to controls, both LPS- and SRBC-fish displayed reduced body mass gain one week post-injection, and LPS-fish actually lost mass. The concomitant increase in metabolic scope and reduced body mass gain of LPS-challenged fish indicates that immune-associated trade-offs are not likely to be shaped by limited oxidative metabolic capacities, but may instead result from limitations in the acquisition, assimilation or efficient use of resources.We are very grateful to Noah Ashley for helpful comments on the manuscript, to all the participants of the Disease Group meeting of the University of Exeter (Cornwall) for useful discussion. All procedures were approved by a prefectorial order from Ariège, France (Agréments de l'établissement pour l’élevage et l'expérimentation no. 0108 and no. SA-013-PB-092; certificats d'autorisation d’élevage et d'expérimentation sur poissons vivants to Oliver Guillaume, no. 09-273 and no. A09-3) and by the University of Sydney Animal Ethics Committee (approval no. L04/10-2010/3/5411). This research was supported by a Marie Curie Reintegration Grant to C.B. (FP7-PEOPLE-IRG-2008 #239257) and an Australian Research Council grant to F.S

High-speed Developments in Avian Genomics

Until recently, definitions of avian genome structure and function were based solely on our knowledge of the chicken genome. The expansion of genomic studies to include nonmodel avian species allows us not only to refine those definitions but also to begin collecting the necessary resources to initiate a truly ecological genomics of birds. In this article we review new genomic technologies that will speed up the investigation of avian genome function. The streamlined nature of avian genomes implies that large-scale transcriptional analyses, studies of the role of regulatory elements and of developmental genes, and even the annotation of avian genomes will yield interesting surprises. We review promising methods used to investigate genome evolution in birds as well as the means by which to integrate functional genomics approaches and transcriptional profiling information into ecological and evolutionary studies.Organismic and Evolutionary Biolog

Understanding the emergence of bacterial pathogens in novel hosts

This is the author accepted manuscript.Data accessibility statement: The computer code to generate the stochastic simulation model can be downloaded fromOur understanding of the ecological and evolutionary context of novel infections is largely based on viral diseases, even though bacterial pathogens may display key differences in the processes underlying their emergence. For instance, host-shift speciation, in which the jump of a pathogen into a novel host species is followed by the specialisation on that host and the loss of infectivity of previous host(s), is commonly observed in viruses, but less often in bacteria. Here, we suggest that adaptation to dealing with different environments, rates of molecular evolution and recombination may influence the extent to which pathogens evolve host generalism or specialism following a jump into a novel host. We then test these hypotheses using a formal model and show that the high levels of phenotypic plasticity, low rates of evolution and the ability to recombine typical of bacterial pathogens should reduce their propensity to specialise on novel host. Novel bacterial infections may therefore be more likely to result in transient spillovers or increased host ranges than in host shifts. Finally, consistent with our predictions, we show that, in two unusual cases of contemporary bacterial host shifts, the bacterial pathogens both have small genomes and rapid rates of substitution. Further tests are required across a greater number of emerging pathogens to assess the validity of our predictions.Natural Environment Research Council (NERC)Wellcome TrustRoyal SocietyLeverhulme Trus

Plasmodium Infections in Natural Populations of Anolis sagrei Reflect Tolerance Rather Than Susceptibility

This is the author accepted manuscript. The final version is available from OUP via the DOI in this record.Parasites can represent formidable selection pressures for hosts, but the cost of infection is sometimes difficult to demonstrate in natural populations. While parasite exploitation strategies may, in some instances, actually inflict low costs on their hosts, the response of hosts to infection is also likely to determine whether or not these costs can be detected. Indeed, costs of infection may be obscured if infected individuals in the wild are those that are the most tolerant, rather than the most susceptible, to infection. Here we test this hypothesis in two natural populations of Anolis sagrei, one of the most common anole lizard of the Bahamas. Plasmodium parasites were detected in > 7% of individuals and belonged to two distinct clades: P. mexicanum and P. floriensis. Infected individuals displayed greater body condition than non-infected ones and we found no association between infection status, stamina, and survival to the end of the breeding season. Furthermore, we found no significant difference in the immuno-competence (measured as a response to phytohemagglutinin challenge) of infected versus non-infected individuals. Taken together, our results suggest that the infected individuals that are caught in the wild are those most able to withstand the cost of the infection and that susceptible, infected individuals have been removed from the population (i.e., through disease-induced mortality). This study highlights the need for caution when interpreting estimates of infection costs in natural populations, as costs may appear low either when parasites exploitation strategies truly inflict low costs on their hosts or when those costs are so high that susceptible hosts are removed from the population.This work was supported by a National Geographic Society [grant #8002-06 to R.C.]; a Natural Environment Research Council [research grant NE/M00256X to C.B.]; The symposium was supported by National Science Foundation [grant # IOS-1637160]; Company of Biologists [grant EA1233] both Simon Lailvaux and Jerry Husak; and bySociety for Integrative and Comparative Biology divisions DAB, DCB, DEC, DEDE, DEE, DNB, and DVM