Exploiting the ZIP4 homologue within the wheat Ph1 locus has identified two lines exhibiting homoeologous crossover in wheat-wild relative hybrids
Exploiting the ZIP4 homologue within the wheat Ph1 locus has identified two lines exhibiting homoeologous crossover in wheat-wild relative hybrids
复制标题
利用小麦 Ph1 基因座内的 ZIP4 同源物，鉴定出两个在小麦-野生近缘杂种中表现出同源交叉的品系
DOI：
10.1101/142596
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Rey M
中科院分区：
文献类型：
--
作者：
Rey M
尽管六倍体小麦具有相关的祖先基因组，但在减数分裂过程中表现为二倍体。小麦Ph1基因座促进同源染色体的精确突触和交叉。虽然六倍体小麦与野生近缘的杂种在中期I减数分裂期间不会发生杂交，但在Ph1缺失突变体与野生近缘的杂交中，Ph1缺失突变体与野生近缘的杂交确实发生了。在过去的40年里，一个SinglePh1缺失(PH1b)突变体一直被利用来进行这一活动。我们在这里展示了化学诱导的突变系，在Ph1基因座的TaZIP4-B2中进行突变选择，当与野生亲缘关系杂交时，显示出高水平的同源交叉。Tazip4-B2突变系可能在多个世代中更稳定，因为多价态导致染色体易位的积累不那么频繁。因此，利用这样的Tazip4-B2突变体，而不是具有完整Ph1基因座缺失的突变体，可能会促进野生相对染色体片段向小麦的导入。
Despite possessing related ancestral genomes, hexaploid wheat behaves as a diploid during meiosis. The wheatPh1locus promotes accurate synapsis and crossover of homologous chromosomes. Interspecific hybrids between wheat and wild relatives are exploited by breeders to introgress important traits from wild relatives into wheat, although in hybrids between hexaploid wheat and wild relatives, which possess only homoeologues, crossovers do not take place during meiosis at metaphase I. However, in hybrids betweenPh1deletion mutants and wild relatives, crossovers do take place. A singlePh1deletion (ph1b) mutant has been exploited for the last 40 years for this activity. We show here that chemically induced mutant lines, selected for a mutation inTaZIP4-B2within thePh1locus, exhibit high levels of homoeologous crossovers when crossed with wild relatives.Tazip4-B2mutant lines may be more stable over multiple generations, as multivalents causing accumulation of chromosome translocations are less frequent. Exploitation of suchTazip4-B2mutants, rather than mutants with wholePh1locus deletions, may therefore improve introgression of wild relative chromosome segments into wheat.