Expression of Pax-2/5/8 in Helobdella sp. (Austin)

Pax-­‐2/5/8 is a member of the Group II Pax genes and, like its relatives, is an important transcription factor most likely involved in cellular differentiation during embryonic development. This highly conserved gene can be found throughout the three superphyla of all bilaterally symmetric animals: Deuterostomes, Ecdysozoans, and Lophotrochozoans. Although Group II Pax genes are involved in the organogenesis and neural patterning of both Deuterostomes and Ecdysozoans, it has yet been unclear what particular role Pax-­‐2/5/8 plays in Lophotrochozoan development. This study, of annelid leech Pax-­‐2/5/8 expression, should help to further elucidate the role of Pax-­‐2/5/8 expression in Lophotrochozoans. More specifically, this project’s aim was to fully sequence the Pax-­‐2/5/8 gene from Helobdella sp. (Austin), and to then begin the characterization of its expression pattern in the developing leech embryo. This preliminary study into annelid Pax-­‐2/5/8 expression has verified the role of Pax-­‐2/5/8 in organogenesis and more specifically in the formation of the leech excretory system. However, further functional studies are necessary to determine if Pax-­‐2/5/8 plays a further role in leech nervous system patterning as well as the specific phenotypic effects that result from disrupted Pax-­‐2/5/8 expression.