TaDEP1基因在普通六倍体小麦及其供体种中的保守与分化

Conservation and Divergence of TaDEP1 Genes in Common Wheat(Triticum aestivum L.)and its Donor Species

根据已知小麦正源基因TaDEP1 cDNA序列设计引物,成功克隆了小麦TaDEP1基因组序列,发现该基因包含5个外显子4,个内含子。通过比较该基因在六倍体普通小麦A、B、D基因组中的差异,筛选出可以区分A、B、D基因组的分子标记Ta956。以中国春缺体-四体系为材料,利用该标记将TaDEP1基因定位于小麦5A、5B和5D。进一步将Ta956扩增的基因组片段在六倍体A、B、D基因组和二倍体小麦以及四倍体小麦的同源基因组间进行比较,发现内含子区域变异较大,特别是六倍体小麦B和D基因组。进一步对TaDEP1编码蛋白分析显示TaDEP1-D的预测功能域明显区别于TaDEP1-A和TaDEP1-B,表明TaDEP1功能可能具有基因组特异性。筛选的区分不同基因组特异分子标记则为今后的品种鉴定提供了依据。

The cloning of the genomic sequence of the wheat orthologous gene TaDEP1 which contains five exons and 4 introns were studied.Genomic sequence comparison revealed a region that can be used as molecular marker（Ta956）to distinguish homoeoalleles of hexaploid wheat.Ta956 was used to map TaDEP1 to wheat chromosomes 5A,5B,and 5D by using Chinese Spring nulli-tetrasomic lines.Sequences corresponding to Ta956 were then isolated and sequenced from hexaploid wheat,its putative donor species and tetraploid wheat.Sequence comparison showed that most variations were present at introns,particularly between the B and D homoeoalleles.Domain analysis showed that proteins from the D genome of hexaploid wheat was more different to those on the A and D genomes,suggesting functional divergence among TaDEP1 proteins from the A,B,and D genomes.The potential of using Ta956 as a marker for variety identification is discussed.