. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. VISCOSITY CHANGES DURING MATURATION 273 Hence we can assume that the liquefaction of the protoplasm that occurs in the Chaetopterus egg is not clue to some substance liberated from the nucleus, for it occurs before the nucleus shows any signs of breaking down. Our results thus indicate that the liquefying effect is due to the protease described by Goldstein (1953). According to Goldstein, as soon as the Chaetopterus egg enters sea water, a proteolytic enzyme system is activated by the entrance of calcium into the cell interi
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. VISCOSITY CHANGES DURING MATURATION 273 Hence we can assume that the liquefaction of the protoplasm that occurs in the Chaetopterus egg is not clue to some substance liberated from the nucleus, for it occurs before the nucleus shows any signs of breaking down. Our results thus indicate that the liquefying effect is due to the protease described by Goldstein (1953). According to Goldstein, as soon as the Chaetopterus egg enters sea water, a proteolytic enzyme system is activated by the entrance of calcium into the cell interior. Goldstein believes that this protease is responsible for the breakdown of. 23456 TIME IN MINUTES FIGURE 1. The viscosity of the protoplasm of the Chaetopterus egg at various intervals of time after the egg has entered sea water. the germinal vesicle; our data seem to show that it also causes a liquefaction of the protoplasm. But before this liquefaction occurs, the protoplasm shows a very brief clotting reaction and this can be interpreted as constituting the mitotic gelation. We believe that both the gelation and the subsequent liquefaction can be caused by the same enzyme, for it is well known that calcium-activated proteases can act to pro- duce both clotting and liquefaction. Indeed, thrombin itself is both a clotting and a proteolytic enzyme. For further discussion, see Heilbrunn (1955).. 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 not perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 1892-; Redfield, Alfred Clarence, 1890-1983. Woods Hole, Mass. : Marine Biological Laboratory
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