Search results for "UNI"
showing 10 items of 37626 documents
Open data and digital morphology
2017
International audience; Over the past two decades, the development of methods for visualizing and analysing specimens digitally, in three and even four dimensions, has transformed the study of living and fossil organisms. However, the initial promise that the widespread application of such methods would facilitate access to the underlying digital data has not been fully achieved. The underlying datasets for many published studies are not readily or freely available, introducing a barrier to verification and reproducibility, and the reuse of data. There is no current agreement or policy on the amount and type of data that should be made available alongside studies that use, and in some cases…
Jumping on the Edge—First Evidence for a 2 × 6-meric Hemocyanin in Springtails
2019
Hemocyanins are respiratory dioxygen carrier proteins found in many arthropods including ancient terrestrial species such as spiders and scorpions as well as marine horseshoe crabs. As hemocyanins are highly conserved in this lineage, it is possible to observe an evolutionary descent through its subunits and their overall structure. Unfortunately, little is known about the structure and function of hexapod hemocyanins. Using recent springtail taxa (Collembola) as models for basal hexapods, and the help of electron microscopy, light scattering, SDS PAGE, and Western blot, we could demonstrate for the first time the presence of 2 × 6-meric hemocyanins in the hemolymph of hexapods. The quatern…
The macroecology of chemical communication in lizards: do climatic factors drive the evolution of signalling glands?
2018
Chemical communication plays a pivotal role in shaping sexual and ecological interactions among animals. In lizards, fundamental mechanisms of sexual selection such as female mate choice have rarely been shown to be influenced by quantitative phenotypic traits (e.g., ornaments), while chemical signals have been found to potentially influence multiple forms of sexual and social interactions, including mate choice and territoriality. Chemical signals in lizards are secreted by glands primarily located on the edge of the cloacae (precloacal glands, PG) and thighs (femoral glands), and whose interspecific and interclade number ranges from 0 to > 100. However, elucidating the factors underlying …
Allograft Inflammatory Factor AIF-1: early immune response in the Mediterranean sea urchin Paracentrotus lividus
2020
Echinoderms are a phylum of deuterostomic invertebrates that play a key role in maintaining the biodiversity of marine ecosystems. They represent a good study model for immunity because their coelomic fluid contains different types of cells involved in the inflammatory response: the coelomocytes. In the case of the sea urchin Paracentrotus lividus, the coelomocyte population is mainly represented by amoebocytes and uncoloured spherulocytes that implement a defence program through phagocytosis, encapsulation, cytotoxicity, and production of antimicrobial agents. The purpose of this study was to find evidence of a possible modulating effect of lipopolysaccharide LPS on the expression of the A…
Sexual selection and the chemical signal design of lacertid lizards
2018
Animal signals can differ considerably in complexity and composition, even among closely related species. Work on vocal and visual signals has revealed how sexual selection can elaborate signals relevant in mate choice or rival assessment, but few studies have investigated this process in chemical signals. In this study, we correlated chemical signalling diversity and richness with degree of sexual dimorphism in a data set of 60 species of the lizard family Lacertidae. The femoral glands of male lacertid lizards exude waxy secretions, of which the lipophilic fraction is known to function in chemical communication. We determined the composition of the gland secretions using gas chromatograph…
Age, sex, mating status, but not social isolation interact to shape basal immunity in a group-living insect
2017
International audience; Immunity is a crucial but costly trait. Individuals should therefore adjust their investment into immunity to their condition and infection risks, which are often determined by their age, sex, mating status and social environment. However, whether and how these four key factors can interact to shape basal immunity remains poorly understood. Here, we tested the simultaneous effects of these factors on hemocyte concentration and phenoloxidase activity in adults of the European earwig. We found that hemocyte concentration increased with age, and that this increase was stronger in males. We also found an age-dependent increase in phenoloxidase activity in males and virgi…
Telomere erosion varies with sex and age at immune challenge but not with maternal antibodies in pigeons
2018
International audience; Conditions experienced early in life have profound impact on adult fitness, and telomere erosion could be a key mechanism in this process. In particular, early exposure to parasites is a frequent phenomenon in young vertebrates, which is associated with several short- and long-term costs such as telomere erosion. However, the timing of exposure to parasites during ontogeny and maternal antibodies can strongly modulate the costs of immunity, and could differentially affect telomere erosion. Here, we compared the effects of an early or late immune challenge on telomere erosion rate in male and female young feral pigeons (Columba livia) having received or not maternal a…
Ecological conditions alter cooperative behaviour and its costs in a chemically defended sawfly
2018
The evolution of cooperation and social behaviour is often studied in isolation from the ecology of organisms. Yet, the selective environment under which individuals evolve is much more complex in nature, consisting of ecological and abiotic interactions in addition to social ones. Here, we measured the life-history costs of cooperative chemical defence in a gregarious social herbivore, Diprion pini pine sawfly larvae, and how these costs vary under different ecological conditions. We ran a rearing experiment where we manipulated diet (resin content) and attack intensity by repeatedly harassing larvae to produce a chemical defence. We show that forcing individuals to allocate more to coope…
Personality, immune response and reproductive success: an appraisal of the pace-of-life syndrome hypothesis.
2017
11 pages; International audience; The pace-of-life syndrome (POLS) hypothesis is an extended concept of the life-history theory that includes behavioural traits. The studies challenging the POLS hypothesis often focus on the relationships between a single personality trait and a physiological and/or life-history trait. While pathogens represent a major selective pressure, few studies have been interested in testing relationships between behavioural syndrome, and several fitness components including immunity. The aim of this study was to address this question in the mealworm beetle, Tenebrio molitor, a model species in immunity studies. The personality score was estimated from a multidimensi…
Environment and Space Rule, but Time also Matters for the Organization of Tropical Pond Metacommunities
2020
Metacommunities are dynamic systems, but the influence of time independently of environmental change in their configuration has been rarely considered. Temporary ponds are excellent ecosystem models, as they have well-defined boundaries in time and space; their communities are relatively isolated through a landscape matrix, and the progress of time leads to major changes through ecological succession and in habitat suitability related to hydroperiod dynamics. Therefore, strong temporal effects are expected to influence their metacommunity structure. We surveyed 30 temporary ponds along the dry tropical region of western Costa Rica and Nicaragua at three different moments of their hydroperio…