Meeting Abstract
P1.73 Monday, Jan. 4 Characterization of apoptosis during the development and metamorphosis of Capitella teleta YAMAGUCHI, E*; SEAVER, EC; University of Hawaii at Manoa, Honolulu; PBRC, Kewalo Marine Lab, Honolulu emiy@hawaii.edu
Apoptosis, or programmed cell death, is vital to the development and metamorphosis of many animals. In deuterostomes, apoptosis is essential for vertebrate post-embryonic development and metamorphosis in sea urchins and ascidians; in ecdysozoans, the hormone ecdysone regulates apoptosis during insect metamorphosis. In lophotrochozoans, apoptosis is associated with the degenerating apical ganglion of the mollusc Ilyanassa obsoleta in metamorphosis-induced animals. Additional data are needed, however, to understand the role of apoptosis during the development and metamorphosis of other lophotrochozoans. Previous studies characterized cell division patterns in larval stages of Capitella teleta (formerly Capitella sp. I), an indirect developing polychaete annelid. During development, we expect the opposing processes of cell division and apoptosis to play a role in sculpting the larva. Apoptosis has not yet been characterized in C. teleta, which undergoes a gradual metamorphosis during which the body elongates and the trochal bands are lost. During metamorphosis, C. teleta first loses its prototroch, then the neurotroch and telotroch, and apoptotic cells are expected in the trochal bands. Apoptosis may also sculpt the elongating head. We characterized the pattern of apoptosis during the development and metamorphosis of C. teleta using the terminal deoxynucleotidyl transferase dUTP nicked end labeling (TUNEL) method. Preliminary data show apoptotic cells in the head ectoderm and scattered cells in the ectoderm of the anterior 2/3 of the mid- to late-larval stages. In addition, labeled cells are observed in a ventral stripe of cells corresponding to the neurotroch in animals undergoing metamorphosis. These results provide a basis for further study on the role of signaling pathways involved in cell division and apoptosis in C. teleta.
