Phosphorylation of histone H3 is correlated with changes in the maintenance of sister chromatid cohesion during meiosis in maize, rather than the condensation of the chromatin.
Phosphorylation of histone H3 is correlated with changes in the maintenance of sister chromatid cohesion during meiosis in maize, rather than the condensation of the chromatin.
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发表时间：
2000-09
影响因子：
4
通讯作者：
E. Kaszás;W. Cande
中科院分区：
文献类型：
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作者：
E. Kaszás;W. Cande
减数分裂染色体凝聚是一个独特的过程，其特征是染色体形态的巨大变化，这是姐妹染色单体配对、突触、重组和分离的正确进展所必需的。我们使用一种能够识别组蛋白H3上丝氨酸10磷酸表位的抗体来监测玉米减数细胞减数分裂过程中H3的磷酸化。据报道，H3磷酸化是动物细胞有丝分裂前期染色体凝聚的一个很好的标志。在这项研究中，我们发现在玉米有丝分裂染色体上，只有中心点周围区域被染色；手臂上几乎没有染色。在减数分裂过程中，在没有H3磷酸化的情况下，从瘦素到二倍素的染色体凝聚发生。相反，H3磷酸化在减数分裂不同阶段的变化与不同阶段姊妹染色单体内聚需求的差异有关。就在核膜破裂之前，组蛋白H3磷酸化首先出现在中心周围区域，然后在中期扩展到整个臂；中期仅中心点周围染色。在afd1（没有第一次分裂）中，一个在减数分裂的许多方面都有缺陷的突变体，包括姐妹染色单体内聚，在中期I有相等的分离，在中期I和后期I染色仅限于中心周围区域；中期和晚期均无染色。我们得出结论，H3中ser10磷酸化水平的变化对应于姐妹染色单体内聚的变化，而不是减数分裂不同阶段染色体凝聚的程度。
Meiotic chromosome condensation is a unique process, characterized by dramatic changes in chromosome morphology that are required for the correct progression of pairing, synapsis, recombination and segregation of sister chromatids. We used an antibody that recognizes a ser 10 phosphoepitope on histone H3 to monitor H3 phosphorylation during meiosis in maize meiocytes. H3 phosphorylation has been reported to be an excellent marker for chromosome condensation during mitotic prophase in animal cells. In this study, we find that on maize mitotic chromosomes only pericentromeric regions are stained; there is little staining on the arms. During meiosis, chromosome condensation from leptotene through diplotene occurs in the absence of H3 phosphorylation. Instead, the changes in H3 phosphorylation at different stages of meiosis correlate with the differences in requirements for sister chromatid cohesion at different stages. Just before nuclear envelope breakdown, histone H3 phosphorylation is seen first in the pericentromeric regions and then extends through the arms at metaphase I; at metaphase II only the pericentromeric regions are stained. In afd1 (absence of first division), a mutant that is defective in many aspects of meiosis including sister chromatid cohesion and has equational separation at metaphase I, staining is restricted to the pericentromeric regions during metaphase I and anaphase I; there is no staining at metaphase II or anaphase II. We conclude that changes in the level of phosphorylation of ser10 in H3 correspond to changes in the cohesion of sister chromatids rather than the extent of chromosome condensation at different stages of meiosis.