Absence of 1-Methyladenine Production in Follicle Cells Obtained from Starfish Ovaries in the Post-Spawning Season: (starfish follicle celis/1-MeAde/GSS/cAMP/post-spawning season).

Abstract

Follicle cells from the ovaries of starfish Asterina pectinifera collected in the breeding season and then kept in an aquarium for three months did not produce 1-methyladenine (1-MeAde) in response to genad-stimulating substance (GSS). The cyclic AMP content of follicle cells of the ovaries was much lower in the post-spawning season than in the spawning season. In the post-spawning season, the cyclic AMP level was increased slightly by GSS, but nor insufficiently for production of 1-MeAde. Addition of 3-isobutyl-1-methylxanthine, a potent phosphodiesterase inhibitor, stimulated the productions of GSS-induced 1-MeAde and cyclic AMP. Adenylate cyclase in membrane preparations of follicle cells from ovaries in the post-spawning season was stimulated by nonhydrolyzable GTP analogs and forskolin. An experiment on ADP-ribosylation with [α-32 P]NAD in the presence of cholera toxin and pertussis toxin showed the presence of two types (stimulatory and inhibitory) of guanine nucleotide-binding regulatory proteins (G-proteins). However, GSS has no effect on the adenylate cyclase activity regardless of the presence of GTP. These findings suggest that GSS does not bind to its receptor in follicle cells of the overy in the post-spawning season, although these cells possess G-proteins and adenylate cyclase. Thus the absence of 1-MeAde production by follicle cells obained from ovaries in the post-spawning season appears to be due to lack of receptor protein for GSS.