Interspecific ovarian transplantation in stick insects (Phasmatodea)

Abstract

Vitellogenic ovarian follicles of Bacillus rossius, Sipyloidea sipylus and Baculum thaii were transplanted into female abdomens of another stick insect, Carausius morosus. Intraspecific transplantations served as controls. Ovarian follicles from all three donnor species were analyzed by immunoblotting using both polyclonal and monoclonal antibodies raised against vitellins of C. morosus. When reacted with rabbit polyclonal antisera, all major vitellin subunits of donor and host species appeared homologous. On the other hand, extensive species-specific differences were revealed in the polypeptide composition of all vitellins by the use of four different monoclonal antibodies. Following transplantation, both host and transplanted follicles were exposed in vivo to 35S-methionine. Follicle polypeptides were then resolved by gel elctrophoresis and the incorporated radioactivity revealed fluorographically. Data showed that host vitellin polypeptides became radioactive in transplanted follicles, suggesting that they entered the oocyte even in those instances in which no immunological counterpart was present in controls. These heterosynthetic ovarian polypeptides were distinguished from autosynthetic proteins by selectively labeling the latter in vitro with 35S-methionine. Finally, transplanted follicles examined ultrastructurally showed that transplantation was invariably followed by encapsulation by the host immune system and that the extent of this phenomenon depended largely on the time of incubation and on the phylogenetic distance between donor and host species. © 1990 Taylor & Francis Group, LLC.