Search results for "POPULATIONS"
showing 10 items of 493 documents
Recurrent domestication by Lepidoptera of genes from their parasites mediated by Bracoviruses
2015
Bracoviruses are symbiotic viruses associated with tens of thousands of species of parasitic wasps that develop within the body of lepidopteran hosts and that collectively parasitize caterpillars of virtually every lepidopteran species. Viral particles are produced in the wasp ovaries and injected into host larvae with the wasp eggs. Once in the host body, the viral DNA circles enclosed in the particles integrate into lepidopteran host cell DNA. Here we show that bracovirus DNA sequences have been inserted repeatedly into lepidopteran genomes, indicating this viral DNA can also enter germline cells. The original mode of Horizontal Gene Transfer (HGT) unveiled here is based on the integrativ…
Les ménestrels du duc. Musique et politique à la cour de Philippe le Hardi (1364-1404)
1999
Place: Dijon
The role of maternal effects in host-parasite interactions: examination of the development of the immune defense in a colonial seabird, the black-leg…
2004
One of the main aims of evolutionary biology is to understand the mechanisms responsible for the phenotypic variation on which natural selection can act. Maternal effects occur when a mother's phenotype or her environment influence her offspring's phenotype. Despite the importance of such effects for the ecology of host-parasite interactions, their role has been relatively neglected to date. In this thesis, we examined how mothers influence the immune defense of their young in an environment that varies in space and time. This work has primarily focused on a colonial seabird, the black-legged kittiwake (Rissa tridactyla). Using this model, we have first shown that specific maternal antibodi…
A Combined Multi-Cohort Approach Reveals Novel and Known Genome-Wide Selection Signatures for Wool Traits in Merino and Merino-Derived Sheep Breeds.
2019
Merino sheep represents a valuable genetic resource worldwide. In this study, we investigated selection signatures in Merino (and Merino-derived) sheep breeds using genome-wide SNP data and two different approaches: a classical F-ST-outlier method and an approach based on the analysis of local ancestry in admixed populations. In order to capture the most reliable signals, we adopted a combined, multi-cohort approach. In particular, scenarios involving four Merino breeds (Spanish Merino, Australian Merino, Chinese Merino, and Sopravissana) were tested via the local ancestry approach, while nine pair-wise breed comparisons contrasting the above breeds, as well as the Gentile di Puglia breed, …
Increasing temperature and productivity change biomass, trophic pyramids and community‐level omega‐3 fatty acid content in subarctic lake food webs
2021
Climate change in the Arctic is outpacing the global average and land-use is intensifying due to exploitation of previously inaccessible or unprofitable natural resources. A comprehensive understanding of how the joint effects of changing climate and productivity modify lake food web structure, biomass, trophic pyramid shape and abundance of physiologically essential biomolecules (omega-3 fatty acids) in the biotic community is lacking. We conducted a space-for-time study in 20 subarctic lakes spanning a climatic (+3.2 degrees C and precipitation: +30%) and chemical (dissolved organic carbon: +10 mg/L, total phosphorus: +45 mu g/L and total nitrogen: +1,000 mu g/L) gradient to test how temp…
Learning to read with Graphogame, an ethnography in a Peruvian rural school
2015
The purpose of the present ethnographic case study is to examine what happens when the literacy learning software Graphogame, designed in Finland, is introduced in a new and radically different context, that of a poor rural school in the Peruvian Andes. The research attempts to complement the quantitative approach which has dominated the research on Graphogame. It also aims to take into consideration the unique circumstances and challenges of rural Peru and how they can affect the use and implementation of the software. I spent two months in the rural school of Quilcas, where nine struggling readers used Graphogame for daily 20 minutes remedial sessions. In this research setting, I conducte…
Les victimes de viol devant les tribunaux à la fin du Moyen Âge d'après les sources dijonnaises et lyonnaises
2005
At the end of the Middle Ages, the manner in which the courts of justice punished rapists clearly shows how seriously such crimes were judged at that time. Endeavoring to increase their juristic power and worrying that the propagation of rape would corrupt the entire society and threaten its survival, impelled the judges and their officials —princes, bishops, and municipal bodies — to deal with all complaints and to initiate inquiries about them. A study of the progressive steps undertaken in the preliminary investigations of these cases reveals that after an inquiry into the accuser's reputation, the judges demanded numerous proofs from the victim about the rape. Moreover, a clinical exami…
Data from: Temporal relationship between genetic and warning signal variation in the aposematic wood tiger moth (Parasemia plantaginis)
2014
Many plants and animals advertise unpalatability through warning signals in the form of colour and shape. Variation in warning signals within local populations is not expected because they are subject to directional selection. However, mounting evidence of warning signal variation within local populations suggests that other selective forces may be acting. Moreover, different selective pressures may act on the individual components of a warning signal. At present, we have a limited understanding about how multiple selection processes operate simultaneously on warning signal components, and even less about their temporal and spatial dynamics. Here, we examined temporal variation of several w…
Data from: Gene flow in the European coal tit, Periparus ater (Aves: Passeriformes): low among Mediterranean populations but high in a continental co…
2018
Extant phylogeographic patterns of Palearctic terrestrial vertebrates are generally believed to have originated from glacial range fragmentation. Post-Pleistocene range expansions have led to the formation of secondary contact zones among genetically distinct taxa. For coal tits (Periparus ater), such a contact zone has been localized in Germany. In this study, we quantified gene flow between Fennoscandian and southern European coal tits using a set of 13 microsatellite loci. STRUCTURE analysis revealed four genetic clusters two of these on Mediterranean islands. German populations were genetically admixed but introgression of southern alleles was evident for Fennoscandian populations. In t…
Data from: Does recognized genetic management in supportive breeding prevent genetic changes in life-history traits?
2014
Supportive breeding is one of the last resort conservation strategies to avoid species extinction. Management of captive populations is challenging because several harmful genetic processes need to be avoided. Several recommendations have been proposed to limit these deleterious effects, but empirical assessments of these strategies remain scarce. We investigated the outcome of a genetic management in a supportive breeding for the Houbara Bustard. At the phenotypic level, we found an increase over generations in the mean values of gamete production, body mass and courtship display rate. Using an animal model, we found that phenotypic changes reflected genetic changes as evidenced by an incr…