Targeted gene knockout reveals a role in meiotic recombination for ZHP-3, a zip3-related protein in Caenorhabditis elegans
Targeted gene knockout reveals a role in meiotic recombination for ZHP-3, a zip3-related protein in Caenorhabditis elegans
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DOI：
10.1128/mcb.24.18.7998-8006.2004
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发表时间：
2004-09-01
影响因子：
5.3
通讯作者：
Loidl, J
中科院分区：
文献类型：
--
作者：
Jantsch, V;Pasierbek, P;Loidl, J
研究发现，减数分裂表达的 Zip3 蛋白从酿酒酵母到人类都是保守的。在面包酵母中，Zip3p 与联会复合体 (SC) 的形成有关，但对该蛋白在多细胞生物中的功能知之甚少。我们在此报告了在线虫秀丽隐杆线虫中 ZIP3 同源物 zhp-3 (K02B12.8) 的成功靶向基因破坏。纯合 zhp-3 敲除蠕虫显示出正常的同源配对和 SC 形成。此外，重组蛋白 Rad-51 的出现时间和核定位在这些动物中似乎正常，表明通过 DNA 双链断裂正确启动减数分裂重组。然而，双线期期间单价体的出现表明，秀丽隐杆线虫ZHP-3蛋白对于同源染色体之间的相互重组以及交叉形成至关重要。在缺乏 ZHP-3 的情况下，相互重组被废除，双链断裂似乎通过替代途径得到修复，导致染色体不相分离，并在减数分裂 I 期间出现单价体。绿色荧光蛋白标记的线虫 ZHP-3 在突触染色体之间形成细胞系，需要 SC 来正确定位。
The meiotically expressed Zip3 protein is found conserved from Saccharomyces cerevisiae to humans. In baker's yeast, Zip3p has been implicated in synaptonemal complex (SC) formation, while little is known about the protein's function in multicellular organisms. We report here the successful targeted gene disruption of zhp-3 (K02B12.8), the ZIP3 homolog in the nematode Caenorhabditis elegans. Homozygous zhp-3 knockout worms show normal homologue pairing and SC formation. Also, the timing of appearance and the nuclear localization of the recombination protein Rad-51 seem normal in these animals, suggesting proper initiation of meiotic recombination by DNA double-strand breaks. However, the occurrence of univalents during diplotene indicates that C. elegans ZHP-3 protein is essential for reciprocal recombination between homologous chromosomes and thus chiasma formation. In the absence of ZHP-3, reciprocal recombination is abolished and double-strand breaks seem to be repaired via alternative pathways, leading to achiasmatic chromosomes and the occurrence of univalents during meiosis I. Green fluorescent protein-tagged C elegans ZHP-3 forms lines between synapsed chromosomes and requires the SC for its proper localization.