Fany as Invited speaker at 2025 Louis-Jeantet Symposium

As part of the invited speakers, Fany presented her talk: Elucidating the molecular basis of mammalian flight

Bats are the only mammals capable of self-powered flight, an evolutionary innovation based on the transformation of forelimbs into wings. The bat wing is characterized by an extreme elongation of the second to fifth digits and a wing membrane called chiropatagium connecting them. This adaptation enabled bats to conquer the aerial environment, contributing to the massive diversification of this taxonomic group. Yet, the molecular underpinnings of this evolutionary innovation remain obscure. In this study, we have explored the molecular basis of bat wing formation through a suite of genomic tools and single-cell analyses. We found that despite the substantial morphological differences between the species, there is an overall conservation of cell populations and gene expression patterns, including interdigital apoptosis. To trace the cellular origin of the chiropatagium, we performed single-cell and label transfer analyses on manually micro-dissected cells and identified a distinct fibroblast population, independent of the apoptosis-associated interdigital cells, as the source of this tissue. These distal cells express a conserved gene program including the transcription factors MEIS2 and TBX3, which are commonly known to specify and pattern the early proximal limb. Transgenic ectopic expression of MEIS2 and TBX3 in mouse distal limb cells resulted in the activation of genes expressed during wing development and phenotypic changes related to wing morphology, such as the fusion of digits. Our results elucidate fundamental molecular mechanisms of bat wing development and illustrate how drastic morphological changes can be achieved through repurposing of existing developmental programs during evolution.

If you want to know more about the symposium you can check their website: (Louis-Jeantet Symposium info)