Evolution; Colour polymorphism; Reptiles; Melanin; Transcriptome; Ecology
Dubey Sylvain, Zwahlen Valerie, Mebert Konrad, Monney Jean-Claude, Golay Philippe, Ott Thomas, Durand Thierry, Thiery Gilles, Kaiser Laura, Geiser Silvia, Ursenbacher Sylvain (2015), Diversifying selection and color-biased dispersal in the asp viper, in BMC Evolutionary Biology
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Dufresnes Christophe, Dubey Sylvain, Ghali Karim, Canestrelli Daniele, Perrin Nicolas, Introgressive hybridization of threatened European tree frogs (Hyla arborea) by introduced H. intermedia in Western Switzerland, in Conservation Genetics
Darvish J, Mohammadi Z, Ghorbani F, Mahmoudi A, Dubey S, Phylogenetic Relationships of Apodemus Kaup, 1829 (Rodentia: Muridae) Species in the Eastern Mediterranean Inferred from Mitochondrial DNA, with Emphasis on Iranian Species, in Journal of Mammalian Evolution
Mebert Konrad, Jagar Tomaz, Grzelj Rok, Cafuta Vesna, Luiselli Luca, Ostanek Erika, Golay Philippe, Dubey Sylvain, Golay Joaquim, Ursenbacher Sylvain, The dynamics of coexistence: habitat sharing versus segregation patterns among three sympatric montane vipers, in Biological Journal of the Linnean Society
Muri daniele, Schuerch Johan, Trim Naike, Golay Joaquim, Baillifard Alexandre, El Taher Athimed, Dubey Sylvain, Thermoregulation and microhabitat choice in the polymorphic asp viper (Vipera aspis), in Journal of Thermal Biology
Understanding the genetic bases and environmental parameters shaping the intraspecific phenotypic variations is an important aspect of evolutionary biology. For example, the colouration of organisms can be determined by various types of pigments, with melanin contributing largely to commonly observed colour variations in vertebrates. Melanin is directly synthetized in organisms and is genetically regulated. Interestingly, it can also be influenced by environmental factors, meaning that complex genotype-environment interactions might influence the melanogenesis pathway. These pathways are well known in vertebrates with an important number of key genes identified. However, most of this information results from studies based on humans, domesticated animals, and laboratory mutants. Hence, studies on wild organisms are scarce, with very few published data on ectothermic tetrapods. To date, major contributors to colour polymorphism observed in natural populations include the melanocortin 1 receptor, the tyrosinase-related protein 1, the agouti signalling protein, and the proopiomelanocortin gene. In more details, the proopiomelanocortin gene is highly conserved in vertebrates and is coding for the melanocyte stimulating hormones, the endorphins, and the adrenocorticotropic hormones, called the melanocortin system. Another interesting aspect of the melanocortin system is that it is not only involved in the melanogenesis pathways but also in behavioural and physiological functions through the interaction between the melanocortin peptides and various melanocortin receptors. As a consequence, the melanogenesis pathway is known for its pleiotropic effects. Indeed, the melanin-based colouration of organisms can be correlated to various traits such as reproductive and anti-predator behaviour, body size, hormone levels, fitness, aggressiveness, or immunocompetence. Despite these known correlations and the complexity of the system, it is only very recently that researcher started focusing on the relationships between the overall gene expression level (including genes of the melanogenesis pathway) via transcriptomic analyses and variations in melanin-based colouration. As a consequence, transcriptomic analyses focusing on individuals of different melanin-based colour morphs remains scarce, preventing a clear understanding of the impact of such phenotypic variations on the overall gene regulation of organisms. Moreover, experimental studies, testing for an effect of melanin-based colouration, in interaction with environmental conditions, on the overall gene expression of organisms are lacking, despite that environmental conditions are known to influence the synthesis of melanin. In this project, I aim at identifying the gene responsible of melanin-based colour polymorphism in the asp viper with transcriptomic analyses and testing for an effect of environmental conditions in interaction with body colour on the regulation of gene expression. Clearly, the transcriptomic study proposed in this project will bring new insights into the overall gene regulation of differently coloured individuals and how environmental variations might affect the expression of genes (involved or not in the melanogenesis). In addition, I will also evaluate how a snake’s body colour influences its survival, growth rate, and habitat choice in the field.