Hybrid Male Sterility in Rice Is Due to Epistatic Interactions with a Pollen Killer Locus
Hybrid Male Sterility in Rice Is Due to Epistatic Interactions with a Pollen Killer Locus
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DOI：
10.1534/genetics.111.132035
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发表时间：
2011-11-01
期刊：
影响因子：
3.3
通讯作者：
Kurata, Nori
中科院分区：
文献类型：
--
作者：
Kubo, Takahiko;Yoshimura, Atsushi;Kurata, Nori
在栽培稻（Oryza sativa）籼粳亚种间的种内杂交中，杂种雄性不育基因S24通过等位基因互作使携带粳稻等位基因（S24-j）的雄配子在杂合杂种中选择性败育。在这项研究中，我们首先检查是否雄性不育是由于单一位点S24。近等基因系（NIL-F1）的分析表明，不同的遗传背景下，S24的表型不同。具有粳稻遗传背景的杂合体S24表现为雄性半不育，而具有籼稻遗传背景的杂合体则未表现不育。该结果表明S24是上位性调节的。对BC 2F 1群体的QTL分析揭示了一个与S24互作的新的不育位点，该位点位于水稻2号染色体上。该基因座被命名为S24的上位性因子（EFS）。进一步的遗传分析表明，S24与纯合的粳稻EFS等位基因（efs-j）组合时会导致雄性不育。结果表明，efs-j是一个隐性孢子体等位基因，而indica等位基因（EFS-i）可以显性抵消由S24杂合性引起的花粉不育。总之，我们的结果表明，一个额外的上位性位点是一个必要的因素，在杂种不育性所造成的等位基因相互作用在一个单一的位点在水稻。这一发现为我们理解杂种不育和小孢子发生的复杂分子机制做出了重要贡献。
In intraspecific crosses between cultivated rice (Oryza sativa) subspecies indica and japonica, the hybrid male sterility gene S24 causes the selective abortion of male gametes carrying the japonica allele (S24-j) via an allelic interaction in the heterozygous hybrids. In this study, we first examined whether male sterility is due solely to the single locus S24. An analysis of near-isogenic lines (NIL-F1) showed different phenotypes for S24 in different genetic backgrounds. The S24 heterozygote with the japonica genetic background showed male semisterility, but no sterility was found in heterozygotes with the indica background. This result indicates that S24 is regulated epistatically. A QTL analysis of a BC2F1 population revealed a novel sterility locus that interacts with S24 and is found on rice chromosome 2. The locus was named Epistatic Factor for S24 (EFS). Further genetic analyses revealed that S24 causes male sterility when in combination with the homozygous japonica EFS allele (efs-j). The results suggest that efs-j is a recessive sporophytic allele, while the indica allele (EFS-i) can dominantly counteract the pollen sterility caused by S24 heterozygosity. In summary, our results demonstrate that an additional epistatic locus is an essential element in the hybrid sterility caused by allelic interaction at a single locus in rice. This finding provides a significant contribution to our understanding of the complex molecular mechanisms underlying hybrid sterility and microsporogenesis.