女性卵巢衰老远比机体其他器官衰老要早。随着人类生育年龄的推迟,卵巢衰老导致的不孕症所占比重越来越大。卵巢衰老是以卵母细胞的数量和质量下降为特征的一个自然生理过程。近年研究发现,沉默信息调节因子2(silence information regul...女性卵巢衰老远比机体其他器官衰老要早。随着人类生育年龄的推迟,卵巢衰老导致的不孕症所占比重越来越大。卵巢衰老是以卵母细胞的数量和质量下降为特征的一个自然生理过程。近年研究发现,沉默信息调节因子2(silence information regulator 2,SIRT2)介导非组蛋白和组蛋白去乙酰化,参与了卵母细胞衰老过程。哺乳动物卵泡中与年龄相关的SIRT2水平降低易致减数分裂缺陷,从而产生低质量的卵母细胞,影响妊娠结局。卵巢衰老是高龄不孕女性不可避免的自然生理过程,尽管目前辅助生殖技术为高龄不孕女性带来了福音,但低质量的卵母细胞也会影响辅助生殖技术的结局。综述SIRT2的定位、SIRT2与卵母细胞减数分裂的关系以及SIRT2在其中的主要作用,进一步介绍SIRT2介导间隙连接蛋白43(connexin 43,Cx43)、组蛋白H4第16位赖氨酸(H4K16)、α-微管蛋白(α-tubulin)、BUBR1和叉头框蛋白O3a(forkhead box O3a,FOXO3a)等蛋白质去乙酰化参与减数分裂过程所涉及的相关信号通路,为防治卵母细胞衰老提供新的思路。展开更多
同源染色体联会时形成的联会复合体(Synaptonemal complex,SC)是由减数分裂前期Ⅰ多种蛋白质聚集而成的超级复合结构。生殖细胞特异性的核蛋白C(2)M(Crossover suppressor on 2 of Manheim)在染色体上高度聚集可以诱导SC的形成。本文采...同源染色体联会时形成的联会复合体(Synaptonemal complex,SC)是由减数分裂前期Ⅰ多种蛋白质聚集而成的超级复合结构。生殖细胞特异性的核蛋白C(2)M(Crossover suppressor on 2 of Manheim)在染色体上高度聚集可以诱导SC的形成。本文采用酵母双杂交方法,利用C(2)M的诱饵表达载体筛选果蝇c DNA文库,共发现40个可能与C(2)M相互作用的蛋白,包括多种DNA及组蛋白结合蛋白、ATPase、转录调节因子。从筛选的结果中,选取wech和Psf1基因构建了转基因果蝇,并在生殖细胞中进行了基因沉默,结果显示联会复合体的消失受到延迟。上述结果表明Wech和Psf1蛋白可能与C(2)M形成复合物,共同参与联会复合体的形成或其稳定性的维持。展开更多
The centromere, which is one of the essential parts of a chromosome, controls kinetochore formation and chromosome segregation during mitosis and meiosis. While centromere function is conserved in eukaryotes, the cent...The centromere, which is one of the essential parts of a chromosome, controls kinetochore formation and chromosome segregation during mitosis and meiosis. While centromere function is conserved in eukaryotes, the centromeric DNA sequences evolve rapidly and have few similarities among species. The histone H3 variant CENH3(CENP-A in human), which mostly exists in centromeric nucleosomes, is a universal active centromere mark in eukaryotes and plays an essential role in centromere identity determination. The relationship between centromeric DNA sequences and centromere identity determination is one of the intriguing questions in studying centromere formation. Due to the discoveries in the past decades, including "neocentromeres" and "centromere inactivation", it is now believed that the centromere identity is determined by epigenetic mechanisms. This review will present recent progress in plant centromere biology.展开更多
文摘同源染色体联会时形成的联会复合体(Synaptonemal complex,SC)是由减数分裂前期Ⅰ多种蛋白质聚集而成的超级复合结构。生殖细胞特异性的核蛋白C(2)M(Crossover suppressor on 2 of Manheim)在染色体上高度聚集可以诱导SC的形成。本文采用酵母双杂交方法,利用C(2)M的诱饵表达载体筛选果蝇c DNA文库,共发现40个可能与C(2)M相互作用的蛋白,包括多种DNA及组蛋白结合蛋白、ATPase、转录调节因子。从筛选的结果中,选取wech和Psf1基因构建了转基因果蝇,并在生殖细胞中进行了基因沉默,结果显示联会复合体的消失受到延迟。上述结果表明Wech和Psf1蛋白可能与C(2)M形成复合物,共同参与联会复合体的形成或其稳定性的维持。
文摘The centromere, which is one of the essential parts of a chromosome, controls kinetochore formation and chromosome segregation during mitosis and meiosis. While centromere function is conserved in eukaryotes, the centromeric DNA sequences evolve rapidly and have few similarities among species. The histone H3 variant CENH3(CENP-A in human), which mostly exists in centromeric nucleosomes, is a universal active centromere mark in eukaryotes and plays an essential role in centromere identity determination. The relationship between centromeric DNA sequences and centromere identity determination is one of the intriguing questions in studying centromere formation. Due to the discoveries in the past decades, including "neocentromeres" and "centromere inactivation", it is now believed that the centromere identity is determined by epigenetic mechanisms. This review will present recent progress in plant centromere biology.
