Arachidonic and other long-chain polyunsaturated fatty acids in spermatophores and spermathecae of Teleogryllus commodus: Significance in prostaglandin-mediated reproductive behaviour

Estimates of weights of fatty acids, especially arachidonic acid, in spermathecae from virgin and mated T. commodus indicate substantial elevation in all fatty acids and particularly arachidonic acid following mating. Analysis of spermatophore lipids suggests that this can be in part accounted for by the contents of one or several spermatophores. Fractionation of total lipids from spermatophores showed that arachidonic acid comprised 24% of phosphotidylcholine and 4% of phosphotidylethanolamine, but was not detected in neutral lipids whereas it was approximately equally distributed over phosphotidylcholine and phosphotidylethanolamine in lipids from spermathecae. These data indicate that in addition to prostaglandin synthetase, the spermatophore contains a physiologically significant quantity of prostaglandin precursor, arachidonic acid, esterified to phospholipid and presumably unavailable for enzymatic action during mating transfer. We also note that proportions of arachidonic acid in the phosphotidylcholine of spermatophores are the highest recorded for this fatty acid in the insect literature, which in conjunction with recent work emphasizes the likely physiological significance of long-chain polyunsaturated fatty acids in insects generally.