Hox and ParaHox gene expression patterns in Polyplacophora (Mollusca)

• Applicant: Dr. Martin Fritsch
• Subject Area: Systematics and Morphology (Zoology) ; Developmental Biology
• Term: from 2013 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 243252611

According to recent molecular analyses and extensive paleontological data, Mollusca has a deep split with two branches: Aculifera (Aplacophora and Polyplacophora) and Conchifera. Thus a hypothetical ancestral mollusc could have either carried a single shell, a serial or no shell at all. In addition the fossil record has revealed that the ancestor of the aplacophoran + polyplacophoran line was a chiton-like mollusk from the late Cambrian, which carried a series of overlapping shell plates. Therefore the body organization of Polyplacophora is of particular interest, as they obviously have a combination of both primitive and derived features. Comparative gene expression analyses show, that Hox and ParaHox genes expressed during ontogeny play a crucial role in the bodyplan formation. This project aims to elucidate the gene expression pattern of Hox and ParaHox genes in the developmental stages of the polyplacophoran Acanthochitona crinitus (Pennant, 1777). By comparing the gene expression pattern of A. crinitus with the already existing gene expression data of gastropods and cephalopods (Conchifera), new insights are gained into which functions the Hox and ParaHox genes may play in the ontogeny of the Mollusca. By comparing Polyplacophora (representing the Aculifera) and representatives of Conchifera, we can reveal both conserved as well as more derived plastic functions of Hox and ParaHox genes in the Mollusca. The project will provide a significant contribution to the evolutionary understanding of the extremely variable body organization of Mollusca and the functions of the developmental genes governing this process. It is part of a large-scale comparative developmental study of different taxa of Mollusca in the lab of Prof. Wanninger, including other key taxa such Solenogastres, Scaphopoda, Bivalvia, Gastropoda, Scaphopoda and Cephalopoda.

• DFG Programme: Research Fellowships
• International Connection: Austria
• Host: Professor Dr. Andreas Wanninger