title: Lack of essential enzymes for the biosynthesis of C19 and C18 steroids in gonads of the migratory locust, Locusta migratoria.
abstract: Ovaries and testes of the African migratory locust, Locusta migratoria migratorioides, were incubated in vitro with six tritiated steroid precursors. Three developmental stages were investigated--1 day, 14 days, and 6 weeks after adult moulting. 20 alpha-Hydroxysteroid dehydrogenase (HSD), 20 beta-HSD, 17 beta-HSD, 3 beta-HSD/isomerase, C17-C20 lyase, glucuronyl-transferase, sulfotransferase, and acyltransferase were identified in both sexes. A synthesis of androgens or estrogens comparable to the vertebrate type, however, was not apparent in the locust gonads. 20 alpha-HSD, 20 beta-HSD, and 17 beta-HSD activities were high, while more important steps in steroid synthesis such as 3 beta-HSD and C17-C20 lyase were far less intense. Ovarian 17 alpha-hydroxylase activity was slight. Aromatase activity was not demonstrated. Water-soluble conjugate formation was high in the incubations of "14th-day" and "6th-week" gonads but was absent in "1st-day" ovaries and testes. Active ester formation of pregnenolone was demonstrated in "6th-week" testes. The other steroid conversions were similar in all developmental stages investigated. Major differences between testes and ovaries were not observed. The gonads of the migratory locust are concluded not to produce androgens or estrogens.
authors.affiliation: Catholic University of Leuven, Zoological Institute, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Swevers
authors.forename: J G
authors.initials: JG
authors.lastname: Lambert
authors.forename: F
authors.initials: F
authors.lastname: Novak
authors.forename: G
authors.initials: G
authors.lastname: Paesen
authors.forename: A
authors.initials: A
authors.lastname: De Loof
mesh_terms: D000818:Animals; D005260:Female; D006066:Gonads / Q000201:enzymology / Q000378:metabolism*; D006110:Grasshoppers / Q000201:enzymology / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D010084:Oxidation-Reduction; D013256:Steroids / Q000096:biosynthesis*
chemical_list: D013256:Steroids