Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1989: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1988: ¥1,300,000 (Direct Cost: ¥1,300,000)
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Research Abstract |
The acid sea water extract from unfertilized sea urchin eggs (egg extract:EE) can induce artificial activation, acceleration of cleavage, and animalization in sea urchin eggs. In this study, we attempted to purify and characterize cleavage accelerating factors (CAF) in EE. EE contains at least two kinds of accelerating factors; that is, a collodion bag-filterable one(MW < 12,000) and a collodion bag-non-filterable one (MW <greater than or equal>12,000). At first, we have tried to purify the former factor with low molecular weight. This collodion bag filterable factor was concentrated and fractionated by gel filtration (Bio Gel P-6 and P-2) and HPLC (ODS C-18). Thus we could obtained a very effective fraction of CAF which seemed to be a nucleotide or nuleoside (MW: <less than On the other hand, the collodion bag-non-filterable factor was applied to DEAE Sephadex A-50 and a fraction containing CAF was obtained. In this fraction, a small amount of proteins was detected, so that the factor seemed to be a nucleotide or nucleoside, binding some proteins. Furthermore, it was found that the collodion bag-non- filterable factor contains a cleavage inhibiting factor which stops cytokinesis completely. Therefore, it seems that a cell cycle is regulated by balance of two antipodal actions of such factors, although this inhibiting factor should be studied more precisely. It was also revealed that neither cytoplasmic free Ca^+ concentration nor cytoplasmic pH are not raised by EE-treatment, but the content of arginine phosphate is increased to the level in fertilized eggs. Such a changes may have some relationship to acceleration of cleavage induced by EE-treatment.
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