Meeting Abstract

P2.24  Tuesday, Jan. 5  Expression of piwi during development and regeneration in the marine polychaete Capitella teleta GIANI, V. C.*; SEAVER, E. C.; University of Hawaii; University of Hawaii vinny_giani@hotmail.com

Capitella teleta (formerly Capitella sp. I) is a polychaete annelid that exhibits robust posterior regeneration. C. teleta undergoes sexual reproduction and following an embryonic period, forms a larva that undergoes metamorphosis into a juvenile worm. Several features of its biology make it an ideal system for regeneration studies, including the fact that the relationship between embryonic development and regeneration can be analyzed. In this study we characterize the expression of the piwi gene throughout the life history of C. teleta. Piwi is a conserved stem cell marker, and is often localized to germ line stem cell populations. The C. teleta genome contains two piwi orthologues and they show very similar expression patterns. Piwi expression is initially detected in early cleavage stage embryos, and is expressed at all stages examined with a dynamic spatial pattern. Piwi is expressed in a pattern consistent with being a stem cell marker in that it is expressed in the posterior growth zone in larval and adult stages. In the gonad of adults, piwi is expressed in immature oocytes within the ovary, but is absent from mature oocytes. We also observe piwi expression in the blastema of regenerating animals, which is localized to the mesoderm. The temporal dynamics of piwi expression over the course of regeneration is currently being characterized. Our description of piwi and another gene eve represent an initial molecular characterization of the regeneration process in polychaete annelids.