. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. LIPID METABOLISM IN SEA URCHIN EMBRYOS 443 nitrogen content. As can be seen from Figure 1, the content of total lipids in un- fertilized eggs was eggs. Since the total nitrogen in the unfertilized eggs amounted to ; eggs, the above value corresponds to 166 nig. total nitrogen and is consistent with the figures of 144 or 178 mg. total nitrogen calculated by Ohman (1945) from the data obtained by Ephrussi and Kapkine (1928) with Paracentrotus liridns, and of or m
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. LIPID METABOLISM IN SEA URCHIN EMBRYOS 443 nitrogen content. As can be seen from Figure 1, the content of total lipids in un- fertilized eggs was eggs. Since the total nitrogen in the unfertilized eggs amounted to ; eggs, the above value corresponds to 166 nig. total nitrogen and is consistent with the figures of 144 or 178 mg. total nitrogen calculated by Ohman (1945) from the data obtained by Ephrussi and Kapkine (1928) with Paracentrotus liridns, and of or mg. total nitrogen obtained by Ohman (1945) with Echinocardium coniatuin. The total lipid content showed essentially no change until the mesenchyme blastula stage, after which it decreased considerably toward the pluteus stage. The quantity of phospholipids changed in a very similar manner to that of total lipid, occupying about one-third of the total lipid throughout the early development. Phospholipids of E. cor datum eggs have also been reported to be around one-third of the total lipid (Ohman, 1945). The total nitrogen, on the other hand, decreased slightly but steadily until the gastrula stage and then showed an increase. Such a decrease during the first 24 hours of development of P. livid us has been reported by Nakano and Monroy (1958), although Gustafson and Hasselberg (1951) reported a constancy in total nitrogen content until at least the early pluteus stage. 3 -. FIGURE 1. Changes in the content of total lipid (O), phospholipids (O) and total nitrogen • during the early development of the sea urchin, Paracentrotus lii'idns. U: unfertilized egg; F: newly fertilized egg; C: cleavage stage (32-64 cells) ; B: blastula ; MB: mesenchyme blastula ; G : gastrula ; PR : prism stage ; PL : Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may n
Size: 1456px × 1716px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
