| Project/Area Number |
05680637
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Developmental biology
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
KUBOTA Hiroshi y. Kyoto University, Lecturer Faculty of Science,, 理学部, 講師 (40115837)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1993: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | cytokinesis / cleavage / a maternal effect mutant / Xenopus laevis / 卵割溝 / 小麦胚芽レクチン |
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| Research Abstract |
Females of a maternal-effect mutant (af) of Xenopus laevis lay eggs whose cleavage furrows do not contract. A small amount of cytoplasm from wild-type eggs, when injected into af eggs, induces contraction of the cleavage furrow in af eggs. This enabled us to isolate contraction-inducing substances from wild-type eggs. The precipitate of 0-40% saturated ammonium sulfate fraction was separated by DEAE ion-exchange column chromatography. Fractions having contraction-inducing activity were collected and re-separated by the same column. Comparing the pattern of SDS-PAGE of each fraction and contraction-inducing activity, we found that 31 kDa and 33 kDa bands were concentrated in the fractions which share the contraction-inducing activity. Further separation by gel-filtration column chromatography showed that active components form very high molecular weight complexes. We are making preparations for isolating genes which encode these proteins by making monoclonalantibodies or by analysing the amino acid sequences of these proteins.
In order to maintain af genes, siblings of mutant females were inbred. Among the descendants, we found a female which lays eggs whose cleavage furrows were abnormal. About a half of the eggs layd by the female were lethal because of the incomplete cytokinesis at the first and second cleavages. This abnormality may be due to insufficiency or functional impediment of a maternal product which is differnt from af gene product.
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