Biology subjects

Pitteloud, C.

Publications and source records attributed to Pitteloud, C..

2 recordsLinked to original sources

bioRxiv2025

Conservation strategy insights for three protected Phengaris butterflies combining genetic and landscape analyses

Biodiversity loss is accelerating globally, with insects among the most affected taxa. Wetlands, crucial ecosystems providing essential services, have experienced significant decline due to agricultural intensification and habitat destruction. These changes threaten species that rely on wetland habitats, such as the Phengaris butterflies, which exhibit complex ecological dependencies on specific host plants and ant species. Their populations are structured into metapopulations, where connectivity between habitat patches plays a crucial role in species persistence. This study focuses on population genomics and landscape analysis of three Phengaris species (P. alcon, P. nausithous, P. teleius) in the Bugey Mountain Massif, France, with the aim of developing a conservation strategy. Using ddRAD sequencing, we analyzed genetic diversity, population structure, and gene flow across multiple localities, revealing distinct population clusters with varying degrees of connectivity. Despite some populations exhibiting high genetic diversity levels, others demonstrate low heterozygosity and signs of genetic isolation, emphasizing conservation concerns. Migration estimates and resistance mapping further identified key dispersal corridors and isolated patches requiring targeted interventions. Our findings support metapopulation conservation strategies that prioritize maintaining connectivity, enhancing degraded patches, and identifying new potential habitats. By combining genomic and landscape data, we propose an evidence-based approach to conservation planning, facilitating adaptive management for Phengaris species. This study provides a practical framework for habitat restoration and corridor management in fragmented ecosystems, ensuring long-term species resilience in rapidly changing landscapes.

evolutionary biology↗

bioRxiv2018

Genomic signatures accompanying the dietary shift to phytophagy in polyphagous beetles

BackgroundThe diversity and evolutionary success of beetles (Coleoptera) are proposed to be related to the diversity of plants on which they feed. Indeed the largest beetle suborder, Polyphaga, mostly includes plant-eaters among its ~315,000 species. In particular, plants defend themselves with a diversity of specialized toxic chemicals. These may impose selective pressures that drive genomic diversification and speciation in phytophagous beetles. However, evidence of changes in beetle gene repertoires driven by such interactions remains largely anecdotal and without explicit hypothesis testing.\n\nResultsTo address this, we explored the genomic consequences of beetle-plant trophic interactions by performing comparative gene family analyses across 18 species representing the two most species-rich beetle suborders. We contrasted the gene contents of species from the mostly plant-eating suborder Polyphaga with those of the mainly predatory Adephaga. We found gene repertoire evolution to be more dynamic, with significantly more adaptive lineage-specific expansions, in the more speciose Polyphaga. Testing the specific hypothesis of adaptation to plant-feeding, we identified families of enzymes putatively involved in beetle-plant interactions that underwent adaptive expansions in Polyphaga. There was especially strong support for the selection hypothesis on large gene families for glutathione S-transferase and carboxylesterase detoxification enzymes.\n\nConclusionsOur explicit modeling of the evolution of gene repertoires across 18 species identifies adaptive lineage-specific gene family expansions that accompany the dietary shift towards plants in beetles. These genomic signatures support the popular hypothesis of a key role for interactions with plant chemical defenses, and for plant-feeding in general, in driving beetle diversification.

evolutionary biology↗