Meeting Abstract

P3.94  Monday, Jan. 6 15:30  Evidence of compensation for loss of the germ line in the marine polychaete annelid, Capitella teleta DANNENBERG, L.C.*; SEAVER, E.C.; Whitney Laboratory for Marine Biosciences, St. Augustine Fl. leah.dannenberg@bobcats.gcsu.edu

The germline is necessary for reproduction, and thus survival of the species. Primordial germ cells (PGCs) are undifferentiated stem cells that give rise to germ cells (sperm and egg), and in many species, PGCs are the sole contributors to the germ line. Many widely used model systems cannot compensate for loss of germline, but these organisms also lack regenerative capabilities. The marine polychaete annelid, Capitella teleta, reproduces sexually, is an excellent model system with a fully sequenced genome, has regenerative ability, and the origin of most larval cell types have been determined. Germline compensation can be studied in this system by deletion of the germline precursor cell in early stage embryos. Macromere 3D, the parent cell of 4d and a germline precursor, was deleted using an infrared laser. Experimental animals were examined for expression of the germline marker CapI-vasa by in situ hybridization in larvae. CapI-vasa is expressed in two PGC clusters, the posterior growth zone and foregut of control larvae. In experimental larvae in which 3D was deleted, CapI-vasa was detected in the posterior growth zone and foregut, but most larvae lacked PGC clusters (n=16/23). However, some larvae had either one or two PGC clusters (4/23). PGCs are detected in larvae following deletion of a non-germline macromere precursor. Our preliminary data indicates evidence of germline compensation in Capitella teleta.