Glycerolipid metabolism during early amphibian embryogenesis. Neutral lipid involvement in fertilization triggered events

1. 1. In order to study glycerolipid metabolism during early embryonic development. Bufo arenarum Hensel female toads were administered [1-3 14glycerol together with hormonal stimulus. 2. 2. Triglycerides comprised 60% of the total label in all developmental stages analyzed. The highest specific activity was observed in phosphatidic acid which underwent a net decrease as a function of development. Phosphatidylcholine was the most actively synthesized phosphoglyceride. 3. 3. A significant decrease in the total lipid labeling, mainly accounted for by triglycerides, was detected at fertilization time concomitant with a net diminution in the content of these neutral lipids. 4. 4. Subcellular studies showed that yolk platelets contain about 99% of the total oocyte triglycerides suggesting that massive breakdown would be confined to this fraction. 5. 5. Present findings evidence that the de novo lipid biosynthesis is operating during the developmental analyzed period. In addition, they would suggest the active role of triglycerides in the energetic events taking place around fertilization.