Why Sequence the Limpet?

The goal of this project is to produce, annotate, and analyze a high-quality draft genomic sequence for a gastropod mollusk, the limpet Lottia scutum. Molluscs and annelids represent two diverse animal phyla that are united (along with several other groups of unsegmented worms) within the superphylum Spiralia, sharing spiral cleavage patterns early in development that give rise to a primitively free-living larval form, the trochophore. This ancient developmental pattern has been conserved at least since the early Cambrian period--over 540 million years. While the molecular biology of early developmental patterning in other ancient groups of organisms, such as arthropods (e.g., flies, insects, crustaceans) and deuterostomes (e.g., sea urchins, ascidians, vertebrates), has been dissected in detail using modern genetic and molecular methods, the ancient spiralian patterning mechanism is primarily known via classical embryological studies. To illuminate these processes and enable computational and experimental comparative analyses of genes and pathways across the three bilaterian superphyla, we will sequence and annotate the draft genome of the plate limpet Lottia scutum. This sequence 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 genome, 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: Eric Edsinger-Gonzalez and David Lindberg (proposers, Univ. of California, Berkeley), Daniel Rokhsar (proposer, JGI), Jeffrey Boore (JGI and UC Berkeley), Billie Swalla (Univ. of Washington), Lisa Nagy (Univ. of Arizona), Bernie Degnan (Univ. of Queensland, Australia).