Why Sequence the Leech?

The goal of this project is to produce, annotate, and analyze a high-quality draft genomic sequence for the leech Helobdella robusta. Helobdella is a model annelid for the study of development and evolution at the molecular, cellular, and organismal levels, as well as research in neurobiology, ecology, toxicology, aquaculture, and biomedicine. At ~350 million base pairs, the genome of Helobdella is compact relative to other oligochaetes, and it provides a reference for both close comparisons with the medicinal leech Hirudo and the environmental sentinel Tubifex (both with significantly larger genomes) as well as more distant comparisons with other metazoa. In this regard, the Helobdella genome will provide one of the first genomes from the superphylum Lophotrochozoa, which will illuminate the origins and early divergence of animals into the three major superphyla, as well as a point of comparison for the diversification of annelids, mollusks, flatworms, and other lophotrochozoan phyla. The sequence, along with additional expressed sequence resources, will enable the cloning of conserved and novel genes and the deep annotation of animal gene families.

CSP project participants: David Weisblat (proposer, Univ. of California, Berkeley), Jeffrey Boore (JGI and UC Berkeley), Daniel Rokhsar (JGI), Marty Shankland (Univ. of Texas), Shirley Bissen (Univ. of Missouri, St Louis), D.H. Shain (Rutgers Univ.), Alexa Bely (Univ. of Maryland), Eduardo Maconyo (Univ. of California, San Diego), Takashi Shimizu (Sapporo Univ.), and Rob Savage (Williams College).