How do gene networks organisation into developmental modules facilitate or constraint shape evolution

While the morphological drivers of ecological radiations have been a frequent and productive subject of study, our understanding of the developmental mechanisms that underlie morphological change during rapid diversification remains much more limited. In last decade, more and more individual case studies provided insights into the specific developmental processes driving the evolution of specific novel and dramatic structures. However, the general rules that govern the evolution of developmental processes remain poorly understood. My primary research goals are to: 1) Identify developmental processes that have evolved in tandem with environmental factors to generate diversity in organismal form, 2) Characterize and model any general rules governing how developmental mechanisms can evolve while still maintaining core developmental functions.

Current projects

  • Rapid mosaic variation of bat color vision evolution

  • Evolution of bat hearing systems and echolocation

  • Other projects: limb evolution and collaborations

Past projects - PhD

  • Tuning signaling pathways by gain/loss of protein isoforms

  • Edar as a regulator of tooth row patterning: a palimpsest story

  • Other collaborations

Eda pathway

During my PhD, I worked on the evo-devo of the Eda Pathway, a signaling pathway which is implicated in the development of ectodermal appendages (such as hair, tooth, nails, scales, feather etc) and which has been shown to be involved in adaptive evolution in vertebrates (see our review in my CV, Sadier et al. TIG). My project was divided in two parts that focused on different aspects of the evolution of this pathway.

Past project: Evolution by tinkering of gene isoforms: the case of Edaradd implicated in skin appendage development

In the first project, I studied the role and the evolution of the two isoforms of the intracellular adaptor EDARADD in mammals by combining developmental, genomic, molecular and phylogenetic studies. I demonstrated a role for the two isoforms of Edaradd in signal transduction and proposed a putative role for gain/loss of isoforms in the evolution of developmental pathways. This work was published in 2015 in BMC Evolutionary Biology: Sadier et al. 2015

Past project: Edar as a regulator of tooth patterning

In my second project, I focused on the receptor EDAR which is implicated in dental development and evolution. I studied its role in the establishment of the molar tooth row and the molar shape in the mouse during development using classical developmental techniques, organ culture and mouse mutants. We used our results to propose a new conceptual framework for the development of the molar row and the first molar. This work is actually submitted to Plos Biology.

Past collaborations

I also worked with other colleagues in collaboration on tooth development in fish and on the role of the Eda pathway in cancer (my 4th year of PhD was funded by this project). These collaborations led to two publication (see CV).