A meiotic chromosomal core consisting of cohesin complex proteins recruits DNA recombination proteins and promotes synapsis in the absence of an axial element in mammalian meiotic cells
A meiotic chromosomal core consisting of cohesin complex proteins recruits DNA recombination proteins and promotes synapsis in the absence of an axial element in mammalian meiotic cells
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DOI：
10.1128/mcb.21.16.5667-5677.2001
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发表时间：
2001-08-01
影响因子：
5.3
通讯作者：
Höög, C
中科院分区：
文献类型：
--
作者：
Pelttari, J;Hoja, MR;Höög, C
减数分裂染色体的行为在几个方面不同于有丝分裂染色体，导致产生遗传上不同的单倍体细胞。这部分归因于减数分裂特异性染色质相关蛋白结构，即联会复合体。该复合体由两个平行的轴向元件组成，每个元件与一对姐妹染色单体相关，以及位于突触同源染色体之间的横向丝。最近，一种不同的蛋白质结构，即粘连蛋白复合物，被证明与减数分裂染色体相关，并且是染色体分离所必需的。为了探索哺乳动物雄性减数分裂细胞中两种不同蛋白质结构（联会复合体和粘连蛋白复合体）的功能，我们分析了轴向元件的缺失如何影响早期减数分裂染色体行为。我们发现联会复合蛋白 3 (SCP3) 是轴元件组装的主要决定因素，并且是将该结构附着到减数分裂染色体所必需的，而 SCP2 有助于塑造轴元件的体内结构。我们还表明，减数分裂核中含有粘连蛋白的染色体核心的形成不需要 SCP3 或 SCP2。我们的结果还表明，在没有轴向元件的情况下，粘连蛋白核心招募重组蛋白并促进同源染色体之间的突触。提出了早期减数分裂染色体配对和联会的模型。
The behavior of meiotic chromosomes differs in several respects from that of their mitotic counterparts, resulting in the generation of genetically distinct haploid cells. This has been attributed in part to a meiosis-specific chromatin-associated protein structure, the synaptonemal complex. This complex consist of two parallel axial elements, each one associated with a pair of sister chromatids, and a transverse filament located between the synapsed homologous chromosomes. Recently, a different protein structure, the cohesin complex, was shown to be associated with meiotic chromosomes and to be required for chromosome segregation. To explore the functions of the two different protein structures, the synaptonemal complex and the cohesin complex, in mammalian male meiotic cells, we have analyzed how absence of the axial element affects early meiotic chromosome behavior. We find that the synaptonemal complex protein 3 (SCP3) is a main determinant of axial-element assembly and is required for attachment of this structure to meiotic chromosomes, whereas SCP2 helps shape the in vivo structure of the axial element. We also show that formation of a cohesin-containing chromosomal core in meiotic nuclei does not require SCP3 or SCP2. Our results also suggest that the cohesin core recruits recombination proteins and promotes synapsis between homologous chromosomes in the absence of an axial element. A model for early meiotic chromosome pairing and synapsis is proposed.