ABSTRACT
The presence of estrogens in echinoderms has been determined previously utilizing various techniques. However, the biosynthesis of estrogens by echinoderms has not been proven. Testicular and body wall tissue minces from the echinoid Lytechinus variegatus were incubated in vitro with radiolabelled estrogens to determine the metabolic fate of potentially endogenous estrogens. Steroid metabolites were identified utilizing thin layer chromatography and product derivatizations coupled with radioisotope image analysis. The precursor estrone was metabolized quickly into estradiol which was converted into an estradiol ester. The precursor estradiol was converted into an estradiol ester and to a lesser extent estrone. One or more aqueous-soluble products were also produced by both the testes and body wall, ranging from 22 to 26 % of the total products. These results indicate that estrone and estradiol are transient intermediates in steroid metabolism and suggest that the functional role of estrogen derivatives should be investigated.
