Identification and characterization of segregation distortion loci along chromosome 5B in tetraploid wheat
Identification and characterization of segregation distortion loci along chromosome 5B in tetraploid wheat
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DOI：
10.1007/s00438-007-0248-7
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发表时间：
2007-08-01
影响因子：
3.1
通讯作者：
Faris, Justin D.
中科院分区：
文献类型：
--
作者：
Kumar, Sunil;Gill, Bikram S.;Faris, Justin D.
分离畸变基因广泛存在于植物和动物中，其作用是影响配子间的优先受精竞争。在这项研究中，我们评估了来自不同细胞遗传砧木的多个互反回交群体中分子标记的分离畸变，这些群体涉及硬脑瘤栽培品种兰登（Langdon）和野生二粒硬脑瘤材料，使我们能够研究5B染色体的分离效应。雌性配子未见分离扭曲现象，但在分析雄性配子分离的3个群体中，存在含有偏分离率标记的基因组区域。一个区域的扭曲是由于LDN等位基因在雄性配子中的优先传递，而不是野生的二聚体等位基因。另一个区域需要雌性LDN 5B染色体的存在才能使携带LDN等位基因的雄性配子优先受精，这表明雌性配子中相应的基因可以调控影响雄性配子分离畸变的基因。第三个扭曲区域是野生二聚体等位基因优先于LDN等位基因通过雄性配子传播的结果。这些结果表明在不同基因型中存在不同的扭曲因子/减数分裂驱动元件，并表明小麦染色体5B上的扭曲因子在染色体位置和潜在机制上存在差异。
Segregation distortion genes are widespread in plants and animals and function by their effect on competition among gametes for preferential fertilization. In this study, we evaluated the segregation distortion of molecular markers in multiple reciprocal backcross populations derived from unique cytogenetic stocks involving the durum cultivar Langdon (LDN) and wild emmer accessions that allowed us to study the effects of chromosome 5B in isolation. No segregation distortion of female gametes was observed, but three populations developed to analyze segregation of male gametes had genomic regions containing markers with skewed segregation ratios. One region of distortion was due to preferential transmission of LDN alleles over wild emmer alleles through male gametes. Another region required the presence of LDN 5B chromosomes in the female for preferential fertilization by male gametes harboring LDN alleles indicating that the corresponding genes in the female gametes can govern genes affecting segregation distortion of male gametes. A third region of distortion was the result of preferential transmission of wild emmer alleles over LDN alleles through male gametes. These results indicate the existence of different distorter/meiotic drive elements among different genotypes and show that distortion factors along wheat chromosome 5B differ in chromosomal location as well as underlying mechanisms.