Estradiol induces proliferation of peroxisome-like microbodies and the production of 3-hydroxy fatty acid diesters, the female pheromones, in the uropygial glands of male and female mallards

G Sasaki,S Bohnet,P.E Kolattukudy,L Rogers

doi:10.1016/s0021-9258(18)92890-5

Abstract

During the mating season the female mallards produce sex pheromones, diesters of 3-hydroxy fatty acids, in their uropygial glands. Subcellular fractionation by sucrose and Nycodenz density gradient centrifugations and electron microscopic examination of the fractions showed that diesters of 3-hydroxy acids and the enzymes that catalyze the formation and esterification of the 3-hydroxy fatty acids are located in the catalase-containing fractions, probably peroxisomes, whereas monoester synthesizing activities are located in the endoplasmic reticulum. Fatty acyl-CoA reductase that would provide fatty alcohol needed for the synthesis of monoester and diester waxes was found both in the peroxisomal and endoplasmic reticulum fraction. Upon daily intramuscular injection of estradiol into the females in the nonmating season, the short chain monoester waxes of the uropygial glands were replaced by long chain monoester waxes, and subsequently the monoester waxes were replaced by diester waxes. Injection of thyroxine with estradiol hastened the induction of the compositional changes including diester synthesis. Similar changes, including the synthesis of the female pheromones, were induced in the uropygial glands by the hormone treatment of males that do not normally produce diesters at any time during their life cycle. The structure and composition of the diesters induced by hormone treatment of both males and females were identical to those of the female pheromones produced during their mating season. Electron microscopic examination of diaminobenzidine-treated glands showed that peroxisomes proliferated in the gland of the females in the mating season and in the estradiol-treated males that produce the diesters.

Highlights

Estradiol Induces Proliferationof Peroxisome-like Microbodies and the Production of 3-Hydroxy Fatty Acid Diesters, the Female Pheromones, inthe Uropygial Glandsof Male and Female Mallards*
Little attention hasbeen paid to thepossibility the fractions showed that diesters of 3-hydroxy acids that thecomposition might be determinebdy the physiological and theenzymes that catalyze the formation eanstderification of the 3-hydroxy fatty acaidres located in the catalase-containing fractions, probably peroxisomes, whereas monoester synthesizing activitiesare located in the endoplasmic reticulum
Upon daily intramuscular injection of estra- acids [4]. This changewas shown to be caused by suppression diol intothe females in the nonmating season, the shoofrtthe expressionof the gene for the thioesterase responsible chain monoester waxes of the uropygial glands were for releasing short chain acidsfrom fatty acid synthase ( 5 ) .A

Summary

RESULTS

Estradiol, the more polar diester became the only component of the secretion of the uropygialgland. Of more polar component witha RFsimilar to thaotf the diesters the five components, the three thatemerged first were idenof 3-hydroxy fatty acids appeared(E only, Fig. 1).Treatment tified by the mass spectra to be 3-hydroxy CR,Cln, and C12 with both estradiol and thyroxine hastened the changes in acid methyl esters, as described before [6]. Injection of olive oil and thyroxine alone did roxine and estradiol matchedwith that isolated from females not produce any change in the thin layer chromatographic during the mating season (Table I). Following cessation of hormonal injec- diesters produced by hormonal injections of the male birds tions the composition of the gland secretion, as revealed by was identicaltothat produced by the females (datanot the thin layer chromatographic pattern, reverted back, first shown)

Fatty alcohol

Estradiol Induces Peroxisomes and Diesters inMallards

Findings

Estradiol Induces PeroxisomesDaiensdters in Mallards