Unit for Integrative Zoology
Department of Evolutionary Biology

Project number: P 34665 Einzelprojekte

Abstract

Cell types have been identified in many metazoans based on their morphology, physiology, and molecular fingerprint, but very little is known about cell types constituting the chaetognath body plan. For decades, Chaetognatha has been a clade of uncertain phylogenetic position due to its mix of protostome and deuterostome traits. Recently, Chaetognatha has been affiliated with Gnathifera, sister to all remaining Spiralia. This phylogenetically informative position renders them crucial to infer the evolution of spiralian and bilaterian cell types and body plans.
This project focusses on long-held questions about the evolution of the chaetognath body plan and its constituent cell types. By identifying terminal cell types and cell states based on their molecular fingerprints and morphology, evolutionary cellular relationships will be inferred between chaetognaths and other bilaterians. Hereby, cell types giving rise to the nervous system as well as the gnathiferan jaw apparatus will take center stage. In this project, cell types in developmental stages and adults of the chaetognath Spadella cephaloptera will be identified by state-of-the-art single cell RNA-sequencing in combination with genome sequencing. Applying cutting-edge single-cell RNA sequencing technology and hybridization chain reaction will help to identify cell types and compare them to those of other bilaterians. This project will advance the chaetognath Spadella cephaloptera from a poorly investigated taxon to a well-studied organism, allowing to gain insights into the development and evolution of these fascinating gnathiferans.
Funding is requested for two PhD students and a technical specialist and collaboration partner is Jean- François Flot (Universite Libre de Bruxelles, Belgium).