Change in the Triglyceride Level in Sea Urchin Eggs and Embryos During Early Development

Abstract

Triglycerides in the embryos of the sea urchin, Anthocidaris crassispina, analyzed by gas‐liquid chromatography, distributed in a range of carbon numbers between 42 and 58 in the sum of three fatty acid residues. During the development until gastrulation, the levels of triglycerides with 48, 56 and 58 carbon numbers decreased at constant rates and the levels of the others decreased at specific stages different with one another, respectively. Thereafter, the amounts of all triglycerides decreased simultaneously. The amount of oxygen consumed in the embryos is enough for the oxidation of mobilized triglycerides during post‐hatching period but is not during pre‐hatching period. The levels of neutral glycerides increased gradually during pre‐hatching period and thereafter decreased. The fatty acid level also increased during pre‐hatching and post‐hatching period. These suggest that the cleavage of triglycerides and the oxidation of their cleavage‐products occur during whole span of early development. During pre‐hatching period, the break down of triglycerides is probably higher in its rate than the rate of their oxidation, resulting in the increase in the levels of neutral glycerides, as well as fatty acids.