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Proc Natl Acad Sci U S A 1975 Nov 01;7211:4469-73. doi: 10.1073/pnas.72.11.4469.
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Turning on of activities in unfertilized sea urchin eggs: correlation with changes of the surface.

Mazia D , Schatten G , Steinhardt R .

Unfertilized sea urchin eggs exposed to low concentrations of ammonia enter into a number of activities which normally appear after fertilization. It is shown that the effects are attributable to ammonia, rather than to NH4+ ions of elevated pH. The same effects are obtained by exposure to isotonic urea and to glycerol at very low ionic strengths. All treatments which produce these changes (such as the turning on of chromosome replication and condensation in unfertilized eggs) also bring about changes of the outer cell surface which are visible in the scanning electron microscope. The most striking indicator is the elongation of the microvilli which cover the surface of the unfertilized egg. The changes of the surface are interpreted as the dissociation of a component from the outer surface layer. This component is not the "vitelline" sheet as defined morphologically or by the ability of the egg to form a fertilization membrane upon insemination. It is proposed further that this component is a peripheral component of the plasma membrane, whose removal modifies the membrane functionally and leads to the derepression of various processes within the egg.

PubMed ID: 1060127
PMC ID: PMC388743
Article link: Proc Natl Acad Sci U S A

Genes referenced: LOC100887844 LOC115919910

References [+] :
Anderson, Oocyte differentiation in the sea urchin, Arbacia punctulata, with particular reference to the origin of cortical granules and their participation in the cortical reaction. 1968, Pubmed, Echinobase