Bascom-Slack C A, Dawson D S
Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
J Cell Biol. 1997 Oct 20;139(2):459-67. doi: 10.1083/jcb.139.2.459.
The recognition and alignment of homologous chromosomes early in meiosis is essential for their subsequent segregation at anaphase I; however, the mechanism by which this occurs is unknown. We demonstrate here that, in the absence of the molecular motor, Kar3p, meiotic cells are blocked with prophase monopolar microtubule arrays and incomplete synaptonemal complex (SC) formation. kar3 mutants exhibit very low levels of heteroallelic recombination. kar3 mutants do produce double-strand breaks that act as initiation sites for meiotic recombination in yeast, but at levels severalfold reduced from wild-type. These data are consistent with a meiotic role for Kar3p in the events that culminate in synapsis of homologues.
减数分裂早期同源染色体的识别和配对对于其随后在减数第一次分裂后期的分离至关重要；然而，这一过程发生的机制尚不清楚。我们在此证明，在缺乏分子马达Kar3p的情况下，减数分裂细胞被前期单极微管阵列和不完全联会复合体（SC）形成所阻滞。kar3突变体表现出极低水平的杂合等位基因重组。kar3突变体确实会产生双链断裂，这些双链断裂在酵母中作为减数分裂重组的起始位点，但与野生型相比，其水平降低了几倍。这些数据与Kar3p在同源染色体联会最终事件中的减数分裂作用一致。
