Studies on enzymes in the developing sea urchin egg

UTILIZATION OF C14-LABELED ACETATE AND GLYCEROL FOR LIPID SYNTHESIS DURING THE EARLY DEVELOPMENT OF SEA URCHIN EMBRYOS

“…In this case, however, the incorporation was not very extensive before the mesenchyme blastula stage and a sharp increase occurred only after this stage. His results thus coincide fairly well with the observation that the activation of many mitochondrial enzymes occurs at the beginning of mesenchylnu blastula (Gustafson and Hasselberg, 1951). Inl the present experiments, on the other hand, the rapid increase was seen to start soon after fertilization, especially with acetate as substrate, and the incorporation curve seems to have more similarity to the population curve of mitochondria obtained by Lenicque (1952, 1955) than to the curve of the activity of mitochondrial enzymes.…”

“…Such a decrease during the first 24 hours of development of P. lividus 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. Figure 2 shows the relationship between the time of incubation with acetate-1-C14 (10 ,uc.)…”

Early Development of the Echinoid Egg Compared With Erythropoiesis*

“…The mRNA, which needs to be invoked for the protein synthesis, must have been made in the egg before it was fertilized, because the same burst of protein synthesis occurs after parthenogenesis or when the egg was exposed to actinomycin before fertilization (Gross & Cousineau, 1963. Only small changes in the kind of protein, for example in enzyme content, have been detected (Gustafson & Hasselberg, 1951 ;Zeuthen, 1953). The respiration rate increases several fold after fertilization.…”

“…There is no increase in size until the alimentary canal is complete (Harvey, 1952). * Each of the major steps in early morphological development-blastula, gastrula, neurula-is preceded by bursts of increased protein, enzyme and RNA synthesis (Gustafson & Hasselberg, 1951;Kavanau, 1954;Elson et al 1954;Brachet, 1960;Lallier, 1963b;Comb et al 1964). When eggs have been separated by centrifugation into nucleated and non-nucleated halves, the nucleated halves can be fertilized and will develop into normal plutei which are smaller than usual (Harvey, 1952).…”

Developmental Physiology

“…Krahl (227) has reviewed the extensive literature (81 pages of bibliography) on metabolism of sea urchin eggs. Suggestive studies on en zymes (228) and growth promoting factors (229) in sea urchin eggs are being carried on by Gustafson et al Barth & Jaeger (230,231,232), Krugelis (233), and Kutsky (234) have continued their studies on the phosphate transfer system in amphibian embryos. The association of phosphatase activity with cellular behavior during amphibian limb regeneration has been studied by Karczmar & Berg (235).…”