Steroids of Invertebrates: the in vitro Production of II-Ketotestosterone and Other Steroids by the Eggs of the Slug, Arion ater rufus (Linn.)

Abstract

THE occurrence of steroids in invertebrate gonads has not been extensively investigated. Chemical assays of the ovaries of echinoderms, molluscs and crustacea, however, have suggested the presence of oestrogenic material¹. Extracts of the eggs of the crustacean Homarus americanus (lobster)² showed oestrogenic activity, tentatively identified as caused by oestradiol 17β. Biological assays of chromatographically purified ovarian extracts of the echinoderms Pisaster ochraceous (starfish)³, Strongylocentrotus franciscanus (sea urchin) and the mollusc Pectenhericius (scallop)⁴ have suggested the presence of both oestrogens and progesterone. Recent investigations of sea urchin and mollusc (oyster) sperm⁵ indicated the capacity of this tissue to metabolize the mammalian steroid oestradiol 17β and testosterone in vitro, to oestrone and androstenedione, respectively. We have found that the hermaphrodite gland of the mollusc Arion ater, during the male phase of reproduction, was capable of testosterone biosynthesis from suitable labelled steroid precursors, and in in vitro incubation conditions was also capable of producing dehydro-epiandrosterone and 20 α-hydroxyprogesterone from endogenous precursors (work to be published by Sandor, Gottfried and Lusis). The present report concerns the in vitro production of steroids from endogenous precursors by the female-phase reproductive products (ova) of the hermaphrodite gland of Arion ater.