. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. METABOLISM IX SEA URCHIN KMRRYOS 447 Distribution of C14 in the lipid fractions after administration of acctatc-1-C14 The total lipids were further fractionated on the silicic acid column as described above and the distribution of radioactivity among the fractions was estimated. Table I shows a typical result obtained with the total lipids from early gastrulae. As to the relative amounts of the various fractions, the most predominant one is fraction 3 (triglycerides + little free fatty acids), occupying of the to
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. METABOLISM IX SEA URCHIN KMRRYOS 447 Distribution of C14 in the lipid fractions after administration of acctatc-1-C14 The total lipids were further fractionated on the silicic acid column as described above and the distribution of radioactivity among the fractions was estimated. Table I shows a typical result obtained with the total lipids from early gastrulae. As to the relative amounts of the various fractions, the most predominant one is fraction 3 (triglycerides + little free fatty acids), occupying of the total lipid. Only fraction 4 was shown to contain an appreciable amount of cholesterol by the Liebermann-Burchard reaction. This fraction amounted to of the total lipid, and thus appeared to consist mainly of free cholesterol. Only a weak reaction was obtained with fraction 2, which would be expected to contain choles- terol esters. Actually, the content of esterified cholesterol in the eggs of E. corda- tum had already been reported to be only of the total cholesterol content (Ohman, 1945), which is consistent with the present result. Samples from frac- tions 7 to 10, eluted by mixtures of chloroform and methanol, were all found to contain phosphorus and should therefore be phospholipids. Since small amounts of silicic acid leaked out of the column with these fractions, in spite of previous washing of the column with chloroform and methanol, the yields of these fractions. 20 10 40 80 100 MeOHinCHCUC0/.) FIGURE 4. Chromatogram of combined phospholipid fractions obtained by the fractionation of total lipid from early gastrulae incubated with acetate-1-C14. Open circle and solid line indicates phosphorus content of each fraction, and solid circle and dotted line indicates total radioactivity of each Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illu
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