Conrad Michael N, Lee Chih-Ying, Chao Gene, Shinohara M, Kosaka H, Shinohara A, Conchello J-A, Dresser Michael E
Program in Molecular, Cell and Developmental Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
Cell. 2008 Jun 27;133(7):1175-87. doi: 10.1016/j.cell.2008.04.047.
Haploidization of the genome in meiosis requires that chromosomes be sorted exclusively into pairs stabilized by synaptonemal complexes (SCs) and crossovers. This sorting and pairing is accompanied by active chromosome positioning in meiotic prophase in which telomeres cluster near the spindle pole to form the bouquet before dispersing around the nuclear envelope. We now describe telomere-led rapid prophase movements (RPMs) that frequently exceed 1 microm/s and persist throughout meiotic prophase. Bouquet formation and RPMs depend on NDJ1, MPS3, and a new member of this pathway, CSM4, which encodes a meiosis-specific nuclear envelope protein required specifically for telomere mobility. RPMs initiate independently of recombination but differ quantitatively in mutants that fail to complete recombination, suggesting that RPMs respond to recombination status. Together with recombination defects described for ndj1, our observations suggest that RPMs and SCs balance the disruption and stabilization of recombinational interactions, respectively, to regulate crossing over.
减数分裂中基因组的单倍体化要求染色体仅被分选到由联会复合体(SCs)和交叉稳定的配对中。这种分选和配对伴随着减数分裂前期活跃的染色体定位,其中端粒在纺锤体极附近聚集形成花束,然后围绕核膜分散。我们现在描述了端粒引导的快速前期运动(RPMs),其速度经常超过1微米/秒,并在整个减数分裂前期持续存在。花束形成和RPMs依赖于NDJ1、MPS3以及该途径的一个新成员CSM4,CSM4编码一种减数分裂特异性核膜蛋白,专门用于端粒移动。RPMs独立于重组启动,但在未能完成重组的突变体中数量上有所不同,这表明RPMs对重组状态有反应。与针对ndj1描述的重组缺陷一起,我们的观察结果表明,RPMs和SCs分别平衡重组相互作用的破坏和稳定,以调节交叉。