Vice Head of Department of Evolutionary Biology
Head of Unit of Integrative Zoology

Abstract

The enormous phenotypic diversity of mollusks is widely known. Lesser considered is the fact that in many molluscan lineages, and on different phylogenetic levels, secondary worm-like (vermiform) bodyplans have evolved (e.g., Solenogastres, Caudofoveata, Scaphopoda, bivalve shipworms, various interstitial and sedentary gastropods such as the vermetids). While current research is often concerned with elucidating the emergence of organismal diversity, the independent emergence of morphological similarity is widely ignored. In a range of novel projects we will address the issue of convergent, secondary vermification in mollusks by analyzing key developmental pathways of selected candidates including solenogasters, caudofoveates, and vermetids. We will compare these data with those from their non-vermiform mollusk kin, in order to elucidate the differences and similarities that are at play during the making of mollusk worms. Specifically, we will reconstruct the morphogenesis of neuromuscular systems and, using relative quantitative transcriptomics and in situ hybridization, we will assess the tempo-spatial expression of genes that are involved in the establishment and regionalization of metazoan body axes (BMP pathway, Wnt, Hox/ParaHox genes), left-right asymmetries (Nodal pathway genes), and factors that are involved in governing metamorphic life cycle transitions (ecdysis-related neuropeptides). Our multi-level comparative analyses will allow for insights into (1) potential ontogenetic alterations that might have led to the evolution of worm-like bodies from ancestors with drastically different, non-vermiform morphologies, and (2) how (dis)similar these mechanisms are between taxa that have convergently evolved worm-like bodies.