| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1995: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1994: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Research Abstract |
The dynamics of microtubule (MT) organization during normal and abnormal meiosis in microsporocytes and megasporocytes of Lilium was investigated with immuno fluorescence using CLSM (confocal laser scanning microscopy) and cryo-sections. MTs radiating from the nucleus at prophase I seemed to be integrated into the bipolar spindle after the nuclear envelope breakdown. On the other hand, phragmoplast MTs seemed not to function in cell plate formation. It was also supposed that the centromeres (kinetochores) play important roles in spindle formation during meiosis. Fortunately, we discovered an antiserum, which preferentially stains the centromere region of meiotic chromosomes in microsporocytes and megasporocytes of Lilium longiflorum, among antisera raised against a variant of histone H1 extracted from pachytene nuclei of this lily. Using this antiserum, we were able clearly to visualize the meiosis-specific dynamics of the centromere, namely, the association and fusion of homologous centromeres at zygotenepachytene in prophase I,the disjunction of the homologous centromeres at diplotene, the doubling of each centromere at metaphase I,non-separation of the sister centromeres at anaphase I and their separation at anaphase II by CLSM.By contrast, this antiserum did not recognize the centromere region of mitotic chromosomes in root-tip meristem. From these results, it is suggested that the antigen is a constitutive centromere protein required for meiosis-specific centromere functioncommon to male and female meiosis. Double staining with anti-tubulin antibody is now in progress to ascertain the relationship between the centromere structure and microtubule attachment.
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