H2A变体在小鼠不同时期雄性生殖细胞核质区的分布

Distribution of H2A variants in mouse male germ cell during different periods

【目的】了解小鼠雄性生殖细胞中macro H2A、H2A.Z和H2A.X 3种组蛋白变体变化与其发育特征间的联系,为揭示原始生殖细胞(PGCs)的发育机理及其分子调控机制奠定基础。【方法】以C57BL/6J小鼠胚胎的中肾和生殖嵴为试验材料,通过免疫荧光染色技术检测11.5dpc、12.5dpc和13.5dpc不同发育时期含有PGCs的组织石蜡切片及单细胞中macro H2A、H2A.X和H2A.Z变体的分布情况。【结果】macro H2A变体在11.5dpc胚胎时主要存在于细胞质中,12.5dpc时在细胞质中的表达增强,但进入生殖嵴后(13.5dpc)表达消失;H2A.X变体在11.5dpc和12.5dpc时存在于PGCs的核质区,13.5dpc时主要存于细胞质,且呈聚集分布;H2A.Z变体在11.5dpc时在PGCs的核质区均有存在,12.5dpc和13.5dpc时主要分布在细胞核,且表达明显增强。【结论】随着PGCs的不断迁移、增殖与分化,macro H2A、H2A.X和H2A.Z 3种组蛋白H2A变体在细胞核质区的分布及表达情况也发生变化,即H2A变体分布特征与PGCs的性别分化及其有丝分裂停止相关。

【Objective】In order to reveal the development mechanism of primitive germ cells（PGCs） and its molecular regulation mechanism, the present experiment was conducted to investigate the relationship between changes and development characteristics of three histone variants viz., macro H2 A, H2 A.Z and H2 A.X in mouse male germ cell.【Method】By taking kidney and genital ridge of C57BL/6j mouse embryos as experimental materials, the distributions ofmacro H2 A, H2 A.Z and H2 A variants in single cell and tissue paraffin section with PGCs were detected during different development stages viz., 11.5dpc, 12.5dpc and 13.5dpc by using immunofluorescence dyeing technique. 【Result】As for macro H2 A variant, it distributed in cytoplasm of 11.5dpc embryo cell mainly, and its expression quantity increased at 12.5dpc stage, while it disappeared in 13.5dpc cell after embryo went into genital ridge. As for H2 A.X variant, it distributed in PGCs cytoplasm and nucleus during 11.5dpc and 12.5dpc stages, and presented aggregated distribution in PGCs cytoplasm at 13.5dpc stage. As for H2 A.Z variant, it distributed in PGCs cytoplasm and nucleus at 11.5dpc stage, and its expression quantity increased in PGCs nucleus at 12.5dpc and 13.5dpc stages. 【Conclusion】With migration, proliferation and differentiation of PGCs, the distribution and expression of three histone H2 A variant viz.,macro H2 A, H2 A.Z and H2 A.X are changing, that is, the distribution characteristics of H2 A variants are related to sex differentiation and cell mitosis stopping of PGCs.