Sex-Based Differences in Triacylglycerol and Phospholipid Subclasses of Gonadal Fatty Acids in the Freshwater Fish Capoeta umbla

The extraction and separation of polar, triacylglycerol (TAG) and phospholipid (PL) subclasses-phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PI), and phosphatidylethanolamine (PE)- were carried out in the gonads to determine fatty acid (FA) compositions using gas chromatography. The major FAs identified in the ovary and testis were palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1n9), arachidonic acid (20:4n6, AA), eicosapentaenoic acid (20:5n3, EPA), docosapentaenoic acid (22:5n3), and docosahexaenoic acid (22:6n3, DHA). In the PL fraction, the proportions of saturated fatty acids (∑SFAs), monounsaturated fatty acids (∑MUFAs), and palmitoleic acid (16:1n7) were higher in the ovary than in the testis, whereas EPA, polyunsaturated fatty acids (∑PUFAs), and the n3/n6 ratio were higher in the testis than in the ovary. In the TAG fraction, ovaries contained higher levels of 16:0 and ∑SFA, whereas the testes contained higher levels of ∑PUFA. This result indicates that ovaries were more dominant in saturated fatty acids and testes are more dominant in polyunsaturated fatty acids.