Sterility in rice via toxin and antidote Crossing wild and domestic rice often results in hybrid sterility. Such genetic barriers can prevent the movement of potentially beneficial genes from wild rice into domestic varieties. To understand the barriers preventing gene flow, Yu et al. mapped a quantitative trait locus (QTL) that determines sterility between wild-type and domestic rice. This QTL encodes two open reading frames (ORFs) that are both expressed during gametogenesis. The ORFs encode a toxin, which affects the development of pollen, and an antidote, which is required for pollen viability. Thus, selfish genetic elements can underlie evolutionary strategies that facilitate reproductive isolation. Science, this issue p. 1130 A toxin-antidote system with a role in postzygotic reproductive isolation of different wild and cultivated rice species is described. Selfish genetic elements are pervasive in eukaryote genomes, but their role remains controversial. We show that qHMS7, a major quantitative genetic locus for hybrid male sterility between wild rice (Oryza meridionalis) and Asian cultivated rice (O. sativa), contains two tightly linked genes [Open Reading Frame 2 (ORF2) and ORF3]. ORF2 encodes a toxic genetic element that aborts pollen in a sporophytic manner, whereas ORF3 encodes an antidote that protects pollen in a gametophytic manner. Pollens lacking ORF3 are selectively eliminated, leading to segregation distortion in the progeny. Analysis of the genetic sequence suggests that ORF3 arose first, followed by gradual functionalization of ORF2. Furthermore, this toxin-antidote system may have promoted the differentiation and/or maintained the genome stability of wild and cultivated rice.

中文翻译：

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一种自私的遗传元素赋予水稻非孟德尔遗传

通过毒素和解毒剂使水稻不育 野生和家养水稻杂交通常会导致杂交不育。这种遗传障碍可以阻止潜在的有益基因从野生稻转移到国内品种。为了了解阻止基因流动的障碍，Yu 等人。绘制了数量性状基因座 (QTL)，该基因座决定了野生型和家养水稻之间的不育性。该 QTL 编码两个开放阅读框 (ORF)，它们都在配子发生过程中表达。ORF 编码一种影响花粉发育的毒素和一种花粉活力所需的解毒剂。因此，自私的遗传因素可以成为促进生殖隔离的进化策略的基础。科学，这个问题 p。1130 描述了一种在不同野生和栽培稻种的合子后生殖隔离中起作用的毒素-解毒剂系统。自私的遗传元素在真核生物基因组中无处不在，但它们的作用仍然存在争议。我们表明 qHMS7 是野生稻 (Oryza meridionalis) 和亚洲栽培稻 (O. sativa) 之间杂交雄性不育的主要数量遗传位点，包含两个紧密相连的基因 [开放阅读框架 2 (ORF2) 和 ORF3]。ORF2 编码一种以孢子体方式中止花粉的有毒遗传元件，而 ORF3 编码一种以配子体方式保护花粉的解毒剂。缺乏 ORF3 的花粉被选择性消除，导致后代的分离扭曲。对基因序列的分析表明 ORF3 首先出现，然后是 ORF2 的逐渐功能化。此外，