Genetic Mapping of the Gamete Eliminator Locus, S2, Causing Hybrid Sterility and Transmission Ratio Distortion Found between Oryza sativa and Oryza glaberrima Cross Combination
Genetic Mapping of the Gamete Eliminator Locus, S2, Causing Hybrid Sterility and Transmission Ratio Distortion Found between Oryza sativa and Oryza glaberrima Cross Combination
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DOI：
10.3390/agriculture11030268
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发表时间：
2021-03
期刊：
影响因子：
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通讯作者：
Myint Zin Mar;Y. Koide;M. Ogata;Daichi Kuniyoshi;Yoshiki Tokuyama;Kiwamu Hikichi;M. Obara;Y. Kishima
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文献类型：
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作者：
Myint Zin Mar;Y. Koide;M. Ogata;Daichi Kuniyoshi;Yoshiki Tokuyama;Kiwamu Hikichi;M. Obara;Y. Kishima
杂种不育是一种阻止物种间基因流动的生殖障碍。在稻属物种中，一些被归类为配子消除子的杂种不育基因座导致花粉和种子不育以及杂种中的不依赖性别的传递率畸变（siTRD）。然而，由于缺乏致病基因的信息，siTRD的分子基础尚未完全表征。在这里，我们分析了一个杂种不育基因座，S2，这是四十多年前报道的，但还没有定位在水稻染色体上。非洲水稻（Oryza glaberrima）和一个近等基因系，具有渐渗的染色体片段从亚洲水稻（Oryza sativa）之间的杂交表现出不育性和siTRD，这证实了S2基因座的存在。全基因组SNP标记调查显示，近等基因系在4号染色体上具有渐渗。进一步的置换作图将S2位点定位在该染色体上22.60 Mb和23.54 Mb之间。在另一个非洲和亚洲水稻品种杂交组合的花药培养的愈伤组织群体中也观察到该染色体区域的显著TRD。这表明S2位点引起的花粉败育发生在花药培养中愈伤组织诱导之前。这也表明在这种种间杂交组合中广泛存在S2介导的siTRD。S2位点的染色体定位对于鉴定致病基因和理解siTRD的分子基础将是有价值的。
Hybrid sterility is a reproductive barrier that prevents gene flow between species. In Oryza species, some hybrid sterility loci, which are classified as gamete eliminators, cause pollen and seed sterility and sex-independent transmission ratio distortion (siTRD) in hybrids. However, the molecular basis of siTRD has not been fully characterized because of lacking information on causative genes. Here, we analyze one of the hybrid sterility loci, S2, which was reported more than forty years ago but has not been located on rice chromosomes. Hybrids between African rice (Oryza glaberrima) and a near-isogenic line that possesses introgressed chromosomal segments from Asian rice (Oryza sativa) showed sterility and siTRD, which confirms the presence of the S2 locus. Genome-wide SNP marker survey revealed that the near-isogenic line has an introgression on chromosome 4. Further substitution mapping located the S2 locus between 22.60 Mb and 23.54 Mb on this chromosome. Significant TRD in this chromosomal region was also observed in a calli population derived from cultured anther in hybrids of another cross combination of African and Asian rice species. This indicates that the pollen abortion caused by the S2 locus occurs before callus induction in anther culture. It also suggests the wide existence of the S2-mediated siTRD in this interspecific cross combination. Chromosomal location of the S2 locus will be valuable for identifying causative genes and for understanding of the molecular basis of siTRD.