Esterification of vertebrate-like steroids in the eastern oyster (Crassostrea virginica)

Triphenyltin alters lipid homeostasis in females of the ramshorn snail Marisa cornuarietis

“…Esterification of steroids occurs upon acyl-CoA moieties, which activation is depended on the concentration of the corresponding fatty acids (Hochberg, 1998). In the oyster Crassostrea virginica, estradiol esters formation was achieved using the fatty acid moieties C16:0, C16:1, C18:0, C18:1, C18:2 and C20:4 (Janer et al, 2004). Exposure of mussels Mytilus edulis to estradiol resulted in the formation of estradiol esters with C16:0, C16:1 and C16:2 fatty acid moieties (Labadie et al, 2007).…”

Fatty acid esters of steroids: Synthesis and metabolism in lipoproteins and adipose tissue

“…However, their biosynthetic pathways have not been fully characterized [95]. When different tissues have been incubated with estradiol, dehydroepiandrosterone or testosterone, the formation of lipophilic steroid conjugates has been reported in several invertebrate groups including molluscs, echinoderms and crustaceans [96][97][98][99]. Some mollusc species appear to synthesize lipophilic steroid conjugates upon exposure to environmental estradiol [100][101][102] or testosterone [103].…”

“…Upon laboratory exposure of the mussel Mytilus edulis to estradiol, Labadie et al identified these conjugates by GC-MS/MS as three D-ring fatty acid esters of estradiol [104]. Several studies indicate that tributyltin, a marine pollutant, might decrease the fatty acylation of steroids in aquatic invertebrates [98,99,105], leading to a relative increase in the amount of unconjugated, biologically active steroid and possibly, to endocrine disruption. Thus, although the biological role of steroid fatty acid esters in invertebrates is not known, fatty acylation might be associated with the homeostatic regulation of bioactive steroid levels in these animals [106,107].…”

Biosynthesis and metabolism of steroids in molluscs

“…Steroid esters do not bind steroid receptors, but they can be hydrolyzed by esterases liberating the active steroid; they are considered to be long-acting steroids [46] and esterification is known to occur in both vertebrate and invertebrate species. Sex steroid esters have been reported in molluscs [44,47,48]. It has been suggested that esterification is the major biotransformation pathway for testosterone in snails, based on the reports that exogenously provided testosterone or estradiol are converted to fatty acid esters and retained in the tissues of the organism by the mud snail I. obsoleta [47] or the mussel M. galloprovincialis [21].…”