Yann BASSAGLIA

Eco-Evo-Devo approach of neuro-muscular complex in the cephalopod Sepia officinalis

Muscular development in cephalopod lead to numerous derived structures essential in the environmental relationships of the organism (e.g. locomotion), as well as its nutrition (prey capture, respiration) and reproduction (intraspecific communication). These structures, mantle, funnel and arms but also chromatophores, are derived structures specific to cephalopods.
We aim to determine the genetic control of this development by investigating the role of genes, essentially transcription factors such as the MRF, the Hand factors or the NK and Pax families, as these genes are known to be involved in myogenesis in other species. We are particularly interested in the link between neurogenesis and myogenesis during development in order to determine the gene network involved in neuro-muscular complex setting up. We also develop gene sequences analysis of these gene families in order to get insight into their structure and their evolution in lophotrochozoans.

An other axis of my research is to elucidate the development of the skin structures allowing the colored patterns of S. officinalis: these skin patterns represent a serious adaptive advantage for benthic cephalopods (benthic cuttlefish and octopus), as they are very efficient camouflage system and a rich repertoire of potential communications. We study the development of the different structures implicated in these patterns (chromatophores and iridophores), the structure of the colored elements involved in their functionality and the control of their distribution.

By a comparative approach with other molluscs, results obtained on the cuttlefish will allow a better understanding of neuro-muscular specificity of cephalopods in the evolutionary context of the loss of protective external shell.

Methods used: Histology, electron microscopy, Immunostaining, cell culture, In situ hybridization, Bio-informatic