Premium
The Role of Intracellular pH in Fertilization of Sand Dollar Eggs Analyzed by Microinjection Method
Author(s) -
HAMAGUCHI M. S.
Publication year - 1982
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.1982.00443.x
Subject(s) - microinjection , intracellular ph , human fertilization , chemistry , hepes , intracellular , cleavage (geology) , chromatography , biochemistry , biophysics , biology , anatomy , microbiology and biotechnology , paleontology , fracture (geology)
The change in intracellular pH (pH i ) upon fertilization and the effects of changing the pH i by microinjection of pH buffers were investigated in the eggs of the sand dollar, Clypeaster japonicus. The pH i was determined by the tint of a pH indicator, phenol red, microinjected into eggs. The pH i ranged from 6.5 to 6.75 in unfertilized eggs and it rose by 0.4 to 0.5 unit within 3 min upon fertilization. The elevated pH i ranging from 7.0 to 7.25 was maintained at least until the first cleavage. As reported in eggs of other species of sea urchin (1–4), development of fertilized eggs which had been transferred to Na‐free sea water immediately after insemination was arrested and the pH i did not rise remaining at the level of unfertilized eggs. Development was initiated in eggs arrested in Na‐free sea water when the pH i was elevated up to the level of fertilized eggs, i.e. 7.0 to 7.25, by microinjecting 1 M HEPES (N‐2‐hydroxyethylpiperazine‐N′‐2‐ethanesulfonic acid)‐KOH buffer at pH 8.0. By microinjection of pH 7.5 buffer, some eggs started development though none of them underwent cleavage. By microinjection of pH 7.0 or pH 6.5 buffer, development was not initiated. The initiation of development depended on the pH value of microinjected pH buffer, and in consequence, on the final pH i . The elongation of microvilli which had been arrested in eggs in Na‐free sea water was also induced by microinjection of pH 8.0 or 7.5 buffer.