Plasticity in Triticeae centromere DNA sequences: a wheat 3 tall wheatgrass (decaploid) model
作 者：Jing Zhao, Weiwei Hao, Caiguo Tang, Han Yao, Baochun Li, Qi Zheng, Zhensheng Li and Xueyong Zhang*
刊物名称：The Plant Journal
文章摘要：Centromeres mediate chromosome attachment to microtubules and maintain the integrity of chromosomes for proper segregation of the sister chromatids during cell division. Advances in the assembly of Triticeae genome sequences combined with the capacity to recover hybrid species derived from very distantly related species, provides an experimental systems for linking retrotransposon amplification and re-position of centromeres via non-mendelian ways in the new polyploid species. The decaploid tall wheatgrass (Thinopyrum ponticum) is one of the most successfully used perennial species in wheat breeding for generating translocation lines with valuable agronomic traits. We found that wheat centromere retrotransposons CRW and Quinta exist widely within the tall wheatgrass. In addition, one of the genome donors for Th. ponticum, Pseudoroegneiria stipifolia (StSt) has been shown to have three new retrotransposons (Abigail, Abia, and CL135) and a satellite repeat, CentSt. Examination of partial amphiploid lines that were generated in the 1970s, demonstrated extensive modification in centromere functional sequences using CentSt, Abigail and Abia as probes. We also detected that St-genome chromosomes were more enriched for the Abigail and CentSt, whereas E-genome chromosomes were enriched for CRW and Quinta in the tall wheatgrass and its closer relatives. It can be concluded that burst and transposition of retrotransposons and re-position of centromeres via non-mendelian way is common in new polyploids derived from interspecific hybrids. Our study also give an example for deeper mechanistic understanding to inform the rational selection of materials in wide cross breeding for transferring alien genes.