Group 1: Evolution and Development of Chordates

Our team is interested in the evolution of morphology during the transition from non-vertebrate chordates to vertebrates. This transition is a good model for studying the evolution of developmental mechanisms for three reasons: i) two whole genome duplications occurred during this transition resulting in an expansion of the number of genes in vertebrates, ii) we have access to a non-vertebrate chordate animal that was shown to be a model of choice for comparative studies, and iii) many studies exist on the molecular mechanisms controlling embryonic development in vertebrates.

The animal model we use is the amphioxus, a cephalochordate, representing the earliest diverging chordate lineage. It has retained all the defining morphological characteristics of chordates (dorsal hollow nerve tube, dorsal notochord, pharyngeal slits, etc....) but remains a very "simple" organism from both an anatomical and genomic point of view.

In our team we have developed a method to induce the spawning on a daily basis during the amphioxus breeding season, as well as basic techniques for studies of embryonic development (HIS, immunolocalizations, pharmacological treatments, microinjection into unfertilized eggs, etc....). We have also developed the complete genome sequencing and the analysis of the epigenome of the European amphioxus, Branchiostoma lanceolatum as well as the RNA-seq, ChIP-seq and ATAC-seq techniques for this model. In addition to continue acquiring new knowledge about the biology, genomics and ecology of amphioxus, we are conducting several research projects concerning the evolution of major developmental processes such as somitogenesis or neural induction.