Xth EMOP, August 2008

Annelids in evolutionary developmental biology and comparative genomics

¹ The Gatty Marine Laboratory, School of Biology, University of St Andrews, St Andrews, Fife, KY16 8LB, UK
² Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
³ Present address, Faculty of Life Sciences, Michael Smith Building, University of Manchester, Oxford Road, Manchester, M13 9PT, UK

^* Correspondence: Ferrier D.E.K., The Gatty Marine Laboratory, School of Biology, University of St Andrews, St Andrews, Fife, KY16 8LB, UK. Tel.: +44 (0)1334 463480 – E-mail: dekf@st-andrews.ac.uk

Abstract

Annelids have had a long history in comparative embryology and morphology, which has helped to establish them in zoology textbooks as an ideal system to understand the evolution of the typical triploblastic, coelomate, protostome condition. In recent years there has been a relative upsurge in embryological data, particularly with regard to the expression and function of developmental control genes. Polychaetes, as well as other annelids such as the parasitic leech, are now also entering the age of comparative genomics. All of this comparative data has had an important impact on our views of the ancestral conditions at various levels of the animal phylogeny, including the bilaterian ancestor and the nature of the annelid ancestor. Here we review some of the recent advances made in annelid comparative development and genomics, revealing a hitherto unsuspected level of complexity in these ancestors. It is also apparent that the transition to a parasitic lifestyle leads to, or requires, extensive modifications and derivations at both the genomic and embryological levels.