Methylation during 1-methyladenine production by starfish ovarian follicle cells

Abstract

1. 1. Under the influence of gonad-stimulating substance (GSS), ovarian follicle cells of the starfish, Asterina pectinifera, produce 1-methyladenine (1-MeAde) for resumption of meiosis in oocytes. As a methyl donor, methionine increased GSS-induced 1-MeAde production in follicle cells, but 5-methyltetrahydrofolate or homarine had no effect. 2. 2. 1-Methyladenine production by GSS in follicle cells was enhanced by l-methionine, d-methionine and seleno- dl-methionine. Without GSS, however, these chemicals alone did not induce 1-MeAde production. 3. 3. Both l- and d-ethionine, competitive inhibitors of methionine, reduced 1-MeAde levels produced by follicle cells in the presence of GSS. Seleno- dl-ethionine also inhibited 1-MeAde production. l-Methionine, d-methionine and seleno- dl-methionine abolished the ethionine-induced inhibition of 1-MeAde production.