Leu J Y, Chua P R, Roeder G S
Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8103, USA.
Cell. 1998 Aug 7;94(3):375-86. doi: 10.1016/s0092-8674(00)81480-4.
The hop2 mutant of S. cerevisiae displays a novel phenotype: meiotic chromosomes form nearly wild-type amounts of synaptonemal complex, but most chromosomes are engaged in synapsis with nonhomologous partners. The meiosis-specific Hop2 protein localizes to chromosomes prior to and during synapsis and in the absence of the double-strand breaks that initiate recombination. hop2 strains sustain a wild-type level of meiotic double-strand breaks, but these breaks remain unrepaired. The hop2 mutant arrests at the pachytene stage of meiotic prophase with the RecA-like protein Dmc1 located at numerous sites along synapsed chromosomes. We propose that the Hop2 protein functions to prevent synapsis between nonhomologous chromosomes.
酿酒酵母的hop2突变体表现出一种新的表型：减数分裂染色体形成的联会复合体数量接近野生型，但大多数染色体与非同源配对对象发生联会。减数分裂特异性的Hop2蛋白在联会之前和期间定位于染色体上，且此时不存在引发重组的双链断裂。hop2菌株维持减数分裂双链断裂的野生型水平，但这些断裂仍未得到修复。hop2突变体在减数分裂前期的粗线期停滞，类RecA蛋白Dmc1位于联会染色体的多个位点。我们推测Hop2蛋白的功能是防止非同源染色体之间发生联会。
