OF EXPERIMENTAL WORK I77 



The classification is based on Sumner and Somer's book on Enzymes (1953) 



Proteolytic 



Proteolytic enzyme in granules of unfertilized egg (A. A. Woodward, Jr., 1949). 



Peptidase in matrix not in granules (Holter, 1936, 1949). 



Trypsin and chymotrypsin. In Psammechinus miliaris and Echinocardium cordatum, 

 dissolve the vitelline membrane of the unfertilized egg, so that when fertilized, 

 no fertilization membrane is formed, but the egg develops (Monne and Broman, 

 1944; Runnstrom, 1948a). Trypsin was used for A. punctulata by Runnstrom 

 in 1950 and by Dan and Mazia in 1951 as the best method of obtaining fertilized 

 eggs without fertilization membranes. Dan used 4 mg. crystalline trypsin in 100 

 cc. sea water for 10 minutes. Effect on membrane was first observed by Kunitz 

 in 1932 (See A. R. Moore, 1949 a, footnote p. 243; 1949 b, footnote p. 207). 



Papain dissolves hyaline layer of developing eggs; no effect of ficin or trypsin 

 (Northrop, 1947; E. B. H.). See under Hyaline Layer. 



"Hatching enzyme", a protease (Sugawara, 1943 a) dissolves fertilization mem- 

 brane of normal blastulae, \n S . pulcherrimus (Ishida, 1936; Sugawara, 1943 a, b). 

 In A. punctulata (Kopac, 1941). For earlier work on other forms, especially 

 Ascidians, see Berrill (1929). 



Autolysis. See Lyon and Shackell (1910a). 



In sperm and egg extracts. Negative results (Gies, 1901). See Loeb (190I; 1913 a, 

 chapter 19; older references given here). Also see Rothschild, 1952. 



Nucleases 



Polynucleotidase; localized in nucleus of egg, also in sperm; present in white 

 half-egg, not in red half (Mazia, 1941). Withdrawn by Mazia in 1950. 



Ribonuclease, RNase. Drop in activity after fertilization which is maintained 

 20 hours (Bernstein, 1949; Krahl, 1950). 



Desoxyribonuclease, DNase. In eggs, half-eggs and sperm; not restricted to nuc- 

 leus but distributed in cytoplasm in unfertilized egg; about equal in the two 

 half-eggs; no change in development to pluteus, but sedimentable fraction 

 increases; activity in egg is 10 times that of mammalian tissue. Activity in 

 sperm is 10 times that of egg per unit volume, lo"^ times per cell (Mazia and 

 Neff, 1947; Mazia, Blumenthal, and Benson, 1948; Mazia, 1949a, b.). 



Inhibition of DNase by usnic acid (Marshak, 1949a; Marshak and Fager, 

 1950). 



Esterases 



Cholinesterase, in Paracentrotus lividus (Augustinsson and Gustafson, 1949). 



Lipase, lipolysin (A. E. Woodward, 1918, 1921; Glaser, 1921b, 1922a, 1923). 

 Just (1929 a, 1930 a) thinks this does not exist. Runnstrom (1949 a) could not 

 find it in .,4. lixula. 



Phosphatase. In unfertilized, fertilized and developing eggs (Mazia, 1941 ; Mazia, 

 Blumenthal, and Benson, 1948; Krugelis, 1947 b. In oocytes (Krugelis, 1947a, 

 b). Not localized in nucleus as indicated by half-eggs (Mazia, 1941; Mazia, 

 Blumenthal, and Benson 1948). 



Adenosintriphosphatase, ATPase. In S. purpuratus (Conners and Scheer, 1947); 

 in P. lividus (Runnstrom, 1949 a, b). 



Carbohydrases 



Hyaluronidase, in A. lixula sperm (Monroy and Ruffo, 1947). 



Hyaluronidase? in A. punctulata eggs (Chambers, 1949). 



These have been questioned by Krauss (1950). See also A. Monroy, L. Tosi, 

 G. Giardina and R. Maggio, 1954, Biol. Bull, 106 : 169-177; and Rothschild, 

 1952. 



