2005 Fiscal Year Final Research Report Summary
A study of the transition mechanism in embryonic cell cycles with translucent Xenopus blastomeres
| Project/Area Number |
16570175
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Developmental biology
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| Research Institution | Yamaguchi University |
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Principal Investigator |
IWAO Yasuhiro Yamaguchi University, Faculty of Science, Professor, 理学部, 教授 (10144916)
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| Co-Investigator(Kenkyū-buntansha) |
UENO Shuichi Yamaguchi University, Faculty of Science, Research assistant, 理学部, 助手 (80363092)
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| Project Period (FY) |
2004 – 2005
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| Keywords | Cleavage / Cell cycle / MBT / Amphibians / MPF / PCNA / Microtubules / Translucent blastomere |
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| Research Abstract |
In order to clarify the mechanism of the elongation and asynchrony of cell cycles after Midblastula transition (MBT), the translucent blastomeres of the frog, Xenopus laevis, were produced by centrifugation and developed in Ca^<2+>-free medium. Many translucent blatomeres were isolated around the 8th cell cycle. To measure the increase in DNA content in each blastomere without any deleterious effect, the blastomeres were treated with a vital DNA-staining fluorescence dye and the fluorescence was measured under the exposure of very weak UV light with very short period. We found G1,S,G2,M phases in each cell cycle based on the change in DNA fluorescence in the nucleus. At first, S and M phases were elongated, and then the cell cycle length greatly increased by the addition on G2 and G1 phases in this order. To inject mRNA of EGFP-PCNA into fertilized eggs, the behavior of PCNA during cell cycles were observed in the live cleaving blastomres. To inject a Ca^<2+>-sensitive fluorescence dye into fertilized eggs, the change in Ca^<2+> concentration during cleavage was measured in live translucent blastomeres. The Ca^<2+> concentration increased just before M phase. Thus, we have developed a novel system to study the behavior of molecules important for cell cycle regulation in live blastomeres during early embryonic cell cycle.
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