Effects of intracellular pH on the mitotic apparatus and mitotic stage in the sand dollar egg.

The effect of change in intracellular pH (pHi) on mitosis was investigated in the sand dollar egg. The pHi in the fertilized egg of Scaphechinus mirabilis and Clypeaster japonicus, which was 7.34 and 7.31, respectively, changed by means of treating the egg at nuclear envelope breakdown with sea water containing acetate and/or ammonia at various values of pH. The mitotic apparatus at pHi 6.70 became larger than that of normal fertilized eggs; that is, the mitotic spindle had the maximal size, especially in length at pHi 6.70. The spindle length linearly decreased when pHi increased from 6.70 to 7.84. By polarization microscopy, the increase in birefringence retardation was detected at slightly acidic pHi, suggesting that the increase in size of the spindle is caused by the increase in the amount of microtubules in the spindle. At pHi 6.30, the organization of the mitotic apparatus was inhibited. Furthermore, slightly acidic pHi caused cleavage retardation or inhibition. By counting the number of the eggs at various mitotic stages with time after treating them with the media, it is found that metaphase was persistent and most of the S. mirabilis eggs were arrested at metaphase under the condition of pHi 6.70. It is concluded that at slightly acidic pH, the microtubules in the spindle are stabilized and more microtubules assembled than those in the normal eggs.

[1]  M. S. Hamaguchi,et al.  Regulation of intracellular pH in sea urchin eggs by medium containing both weak acid and base. , 1997, Cell structure and function.

[2]  I. Vernos,et al.  Motors involved in spindle assembly and chromosome segregation. , 1996, Current opinion in cell biology.

[3]  K. Suprenant,et al.  pH-dependent solubility and assembly of microtubules in bovine brain extracts. , 1994, Cell motility and the cytoskeleton.

[4]  T. Arai,et al.  Different reactivity with monoclonal anti-tubulin antibodies between native and fixed mitotic microtubules in sea urchin eggs. , 1994, Cell motility and the cytoskeleton.

[5]  E. Salmon,et al.  Buffer conditions and non-tubulin factors critically affect the microtubule dynamic instability of sea urchin egg tubulin. , 1992, Cell motility and the cytoskeleton.

[6]  K. Suprenant.  Unidirectional microtubule assembly in cell-free extracts of Spisula solidissima oocytes is regulated by subtle changes in pH. , 1991, Cell motility and the cytoskeleton.

[7]  N. Grandin,et al.  Cycling of intracellular pH during cell division of Xenopus embryos is a cytoplasmic activity depending on protein synthesis and phosphorylation , 1990, The Journal of cell biology.

[8]  K. Suprenant.  Alkaline pH favors microtubule self-assembly in surf clam, Spisula solidissima, oocyte extracts. , 1989, Experimental cell research.

[9]  H. Sakai,et al.  Redistribution of fluorescently labeled tubulin in the mitotic apparatus of sand dollar eggs and the effects of taxol. , 1987, Cell structure and function.

[10]  K. Suprenant,et al.  Temperature and pH govern the self-assembly of microtubules from unfertilized sea-urchin egg extracts. , 1987, Journal of cell science.

[11]  D. Epel.  14 – Intracellular pH and Cell Proliferation , 1987 .

[12]  E. Rozengurt.  Early signals in the mitogenic response. , 1986, Science.

[13]  D. Epel,et al.  The relation between intracellular pH and rate of protein synthesis in sea urchin eggs and the existence of a pH-independent event triggered by ammonia. , 1986, Experimental cell research.

[14]  G. Schatten,et al.  Intracellular pH shift leads to microtubule assembly and microtubule-mediated motility during sea urchin fertilization: correlations between elevated intracellular pH and microtubule activity and depressed intracellular pH and microtubule disassembly. , 1985, European journal of cell biology.

[15]  B. Brinkley,et al.  Cytoplasmic microtubule assembly-disassembly from endogenous tubulin in a Brij-lysed cell model , 1983, The Journal of cell biology.

[16]  M. Hamaguchi.  The Role of Intracellular pH in Fertilization of Sand Dollar Eggs Analyzed by Microinjection Method , 1982, Development, growth & differentiation.

[17]  R. Steinhardt,et al.  Observations on intracellular pH during cleavage of eggs of Xenopus laevis , 1981, The Journal of cell biology.

[18]  R. Nuccitelli,et al.  Direct measurement of intracellular pH changes in Xenopus eggs at fertilization and cleavage , 1981, The Journal of cell biology.

[19]  Y. Hiramoto,et al.  Quantitative studies on the polarization optical properties of living cells. I. Microphotometric birefringence detection system , 1981, The Journal of cell biology.

[20]  Pfeiffer,et al.  Microtubule assembly and disassembly at alkaline pH , 1981, The Journal of cell biology.

[21]  Y. Hiramoto,et al.  Quantitative studies on the polarization optical properties of living cells II. The role of microtubules in birefringence of the spindle of the sea urchin egg , 1981, The Journal of cell biology.

[22]  C. Keller,et al.  Altered in vitro phosphorylation of specific proteins accompanies fertilization of Strongylocentrotus purpuratus eggs. , 1980, Developmental biology.

[23]  R. Steinhardt,et al.  Direct measurement of intracellular pH during metabolic derepression of the sea urchin egg , 1978, Nature.

[24]  A. C. Burton,et al.  The relation of cycling of intracellular pH to mitosis in the acellular slime mould Physarum polycephalum , 1977, Journal of cellular physiology.

[25]  F. Matsumura,et al.  Polymorphism of tubulin assembly. In vitro formation of sheet, twisted ribbon and microtubule. , 1976, Biochimica et biophysica acta.

[26]  G. Borisy,et al.  Ionic and nucleotide requirements for microtubule polymerization in vitro. , 1975, Biochemistry.

[27]  Y. Hiramoto.  A method of microinjection. , 1974, Experimental cell research.

[28]  R. Kane.  THE MITOTIC APPARATUS: ISOLATION BY CONTROLLED pH , 1962, The Journal of cell biology.

[29]  M. H. Jacobs.  SOME ASPECTS OF CELL PERMEABILITY TO WEAK ELECTROLYTES , 1940 .