RELATION OF CARNITINE TO FORMATION OF PHOSPHATIDYL-BETA-METHYLCHOLINE BY TENEBRIO MOLITOR L LARVAE

Results demonstrate that Tenebrio molitor larvae can incorporate β-methylcholine into their phospholipids and that β-methylcholine spares larval choline. Phosphatidyl-β-methylcholine is detected when larvae are reared on a diet in which choline is replaced by β-methylcholine. Results indicate that, in contrast to housefly and blowfly larvae, Tenebrio larvae do not metabolize carnitine to β-methylcholine. The same phospholipids were found with all rearing conditions. They were lecithin, sphingomyelin, phosphatidylethanolamine, phosphatidylserine and two others tentatively identified as cardiolipin and phosphatidylinositol. The ratio of lecithin to sphingomyelin and to the combined other phospholipids did not vary significantly, regardless of the rearing conditions. Larvae reared on diets lacking either choline or carnitine contained more lipid phosphorus per gram of tissue than those reared on a complete diet. The fatty acid composition of the neutral lipids was similar regardless of the rearing conditions. Oleic acid represented greater than 55% of the total fatty acids, and unsaturated fatty acids comprised 75-80% of the total. Palmitic acid was the predominant saturated fatty acid. © 1969 American Oil Chemists' Society.