McGinn, N.A.*; Walker, C.W.: Vitellogenesis in the green sea urchin, Strongylocentrotus droebachiensis: Localization of vitellogenin protein in gonadal tissue

The green sea urchin, Strongylocentrotus droebachiensis, is the focus of a commercial fishery and an aquaculture candidate. It is therefore imperative that we understand the general and reproductive biology of this species. In particular, vitellogenesis is a process in sea urchins on which little basic research has been done. Vitellogenesis is vital to successful reproduction and the vitellogenin protein may influence the palatability of sea urchin roe. Sea urchins are unique in that males as well as females normally produce and use vitellogenin. This study explores some details of vitellogenesis in the green sea urchin. Immunohistochemistry was performed on gonadal sections using a vitellogenin antibody prepared against a partial sequence of a Strongylocentrotid vitellogenin protein. Immunohistochemical results provide information on the localization of the vitellogenin protein in gonadal tissue. Novel observations include the labeling of mature sperm and connective tissue cells associated with the outer gonadal wall by a vitellogenin antibody. This study and future work on vitellogenesis in commercial sea urchin species will be important as natural stocks continue to decline and interest in aquaculture increases.