Phosphatidylcholine synthesis in adult Dirofilaria immitis females

Crude homogenates of adult Dirofilaria immitis females were able to incorporate choline into phosphatidylcholine (PC) and also were able to methylate phosphatidyl (N,N-dimethyl)-ethanolamine, using S-adenosylmethionine as the methyl donor, to form PC. The finding of choline phosphotransferase (EC 2·7·8·2) and phosphatidyl (N,N-dimethyl) ethanolamine methyltransferase activity in the paniculate (mainly microsomal) fraction of the homogenates provided further evidence that adult D. immitis females can synthesize PC by way of choline and cytidine 5'-diphosphocholine (Kennedy pathway) and also by way of S-adenosylmethionine-mediated sequential methylation of phosphatidylethanolamine (Bremer-Greenberg pathway).