黑麦CenH3基因克隆及其在小麦1BL/1RS易位染色体中的定位

Cloning of the CenH3 Gene in Rye and Its Location of 1BL/1RS Translocated Chromosome

黑麦属蕴藏着丰富的遗传变异和改良小麦品质的优良基因,将其导入小麦能够拓宽小麦的遗传基础、丰富小麦的遗传变异。研究采用分子克隆技术获得黑麦CenH3基因的部分片段,并进行探针标记;同时,利用基因组原位杂交技术,筛选出32份1BL/1RS易位系;应用FISH技术,检测筛选出的32份1BL/1RS易位系,所有1BL/1RS易位系材料中均未发现黑麦CenH3基因的信号。但是,应用小麦和黑麦特异着丝粒DNA序列进行FISH检测,2个信号均出现在所有被检测的1BL/1RS易位系材料中。说明1BL/1RS易位染色体在不同小麦背景和山羊草属背景中均能稳定遗传,1RS的着丝粒DNA序列对1BS的着丝粒DNA序列有很好的补偿性,与小麦CenH3蛋白相互作用指导易位染色体正确分离且稳定遗传。

Rye containg a lot of resistance genes is an important genetic resource for wheat improvement. Transferring valuable genes of rye（Secale cereale L.）into hexaploid wheat（Triticum aestivum L.）can widen the genetic constitution and enrich variation of wheat. We obtained a part of CenH3 gene using technology of molecular cloning and applied for Digoxigenin- labelled g DNA probes of the CenH3 gene. Meanwhile, including Ae. kotschyi cytoplasm of 1BL/1RS type, 32 samples of different genetic background belong to1BL/1RS translocation lines, and these 1BL/1RS translocation lines were tested with genomic in situ hybridization（GISH）and fluorescent in situ hybridization（FISH）. The result showed that there was no sigals of CenH3 gene of rye. However, two sigals from special tandem repeats of centromere of wheat and rye were found in all samples. So DNA sequence of centromere from 1RS was also considered as a compensatory substitute of 1BS, and the interaction of the CenH3 protein of wheat and DNA sequence of centromere of rye could lead to correct segregation of chromosomes and steadily hereditary in different genetic background.