Non-B-form DNA is associated with centromere stability in newly-formed polyploid wheat  

作　　者：Congyang Yi Qian Liu Yuhong Huang Chang Liu Xianrui Guo Chaolan Fan Kaibiao Zhang Yang Liu Fangpu Han 

机构地区：[1]Institute of Genetics and Developmental Biology,Chinese Academy of Sciences,Beijing 100101,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Science China(Life Sciences)》2024年第7期1479-1488,共10页中国科学（生命科学英文版）

基　　金：supported by the National Natural Science Foundation of China(31991212);the National Key Research and Development Program of China(2022YFF1003303)。

摘　　要：Non-B-form DNA differs from the classic B-DNA double helix structure and plays a crucial regulatory role in replication and transcription.However,the role of non-B-form DNA in centromeres,especially in polyploid wheat,remains elusive.Here,we systematically analyzed seven non-B-form DNA motif profiles(A-phased DNA repeat,direct repeat,G-quadruplex,inverted repeat,mirror repeat,short tandem repeat,and Z-DNA)in hexaploid wheat.We found that three of these non-B-form DNA motifs were enriched at centromeric regions,especially at the CENH3-binding sites,suggesting that non-B-form DNA may create a favorable loading environment for the CENH3 nucleosome.To investigate the dynamics of centromeric non-B form DNA during the alloploidization process,we analyzed DNA secondary structure using CENH3 ChIP-seq data from newly formed allotetraploid wheat and its two diploid ancestors.We found that newly formed allotetraploid wheat formed more non-B-form DNA in centromeric regions compared with their parents,suggesting that non-B-form DNA is related to the localization of the centromeric regions in newly formed wheat.Furthermore,non-B-form DNA enriched in the centromeric regions was found to preferentially form on young LTR retrotransposons,explaining CENH3's tendency to bind to younger LTR.Collectively,our study describes the landscape of non-B-form DNA in the wheat genome,and sheds light on its potential role in the evolution of polyploid centromeres.

关 键 词：non-B-form DNA polyploid wheat CENTROMERE RETROTRANSPOSON 

分 类 号：S512.1[农业科学—作物学]