Couteau F, Belzile F, Horlow C, Grandjean O, Vezon D, Doutriaux M P
Institut de Biotechnologie des Plantes, Bâtiment 630, Université Paris-Sud, 91405 Orsay, France.
Plant Cell. 1999 Sep;11(9):1623-34. doi: 10.1105/tpc.11.9.1623.
In yeast, the DMC1 gene is required for interhomolog recombination, which is an essential step for bivalent formation and the correct partition of chromosomes during meiosis I. By using a reverse genetics approach, we were able to identify a T-DNA insertion in AtDMC1, the Arabidopsis homolog of DMC1. Homozygotes for the AtDMC1 insertion failed to express AtDMC1, and their residual fertility was 1.5% that of the wild type. Complete fertility was restored in mutant plants when a wild-type copy of the AtDMC1 gene was reintroduced. Cytogenetical analysis points to a correlation of the sterility phenotype with severely disturbed chromosome behavior during both male and female meiosis. In this study, our data demonstrate that AtDMC1 function is crucial for meiosis in Arabidopsis. However, meiosis can be completed in the Arabidopsis dmc1 mutant, which is not the case for mouse or some yeast mutants.
在酵母中，DMC1基因是同源重组所必需的，而同源重组是减数分裂I期间二价体形成和染色体正确分配的关键步骤。通过反向遗传学方法，我们得以鉴定出拟南芥中DMC1的同源基因AtDMC1中的一个T-DNA插入。AtDMC1插入的纯合子无法表达AtDMC1，其剩余育性仅为野生型的1.5%。当重新导入AtDMC1基因的野生型拷贝时，突变植株恢复了完全育性。细胞遗传学分析表明，不育表型与雌雄减数分裂过程中染色体行为的严重紊乱相关。在本研究中，我们的数据表明AtDMC1功能对拟南芥减数分裂至关重要。然而，拟南芥dmc1突变体能够完成减数分裂，而小鼠或一些酵母突变体则不然。
