Characterization and expression of a sea star otx ortholog (Protxß1/2) in the larva of Patiriella regularis.

ABSTRACT

A transcript of otx from the sea star Patiriella regularis (Protxß1/2) was characterized and its expression in early bipinnaria larvae was documented by whole mount in situ hybridization (WMISH). The nucleotide sequence exhibited 94% identity with Amotxß1/2 from the closely related species Patiria miniata. Protxß1/2 was expressed strongly in the developing archenteron in the future fore and mid-gut regions. This was followed by expression of Protxß1/2 in the developing enterocoels, mesodermal derivatives. This suggests a role for Protx in endomesoderm development. In coelom development, Protxß1/2 was first expressed in the left coelom. Subsequently expression was evident in the right coelom, but localization was never as strong as in the left coelom. This asymmetry in Protxß1/2 expression in the coeloms was evident up to the stage when they started to extend posteriorly. These data indicate that Protxß1/2 may have a role in coelom development, particularly in the left coelom, a definitive adult structure.