Unveiling the distinctive traits of functional rye centromeres:minisatellites,retrotransposons,and R-loop formation  

作　　者：Chang Liu Shulan Fu Congyang Yi Yang Liu Yuhong Huang Xianrui Guo Kaibiao Zhang Qian Liu James A.Birchler Fangpu Han 

机构地区：[1]State Key Laboratory of Plant Cell and Chromosome Engineering,Institute of Genetics and Developmental Biology,Chinese Academy of Sciences,Beijing 100101,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Key Laboratory for Plant Genetics and Breeding,Sichuan Agricultural University,Chengdu 611130,China [4]Division of Biological Science,University of Missouri,Columbia 65211-7400,USA

出　　处：《Science China(Life Sciences)》2024年第9期1989-2002,共14页中国科学（生命科学英文版）

基　　金：supported by the National Natural Science Foundation of China(31991212,31920103006)。

摘　　要：Centromeres play a vital role in cellular division by facilitating kinetochore assembly and spindle attachments.Despite their conserved functionality,centromeric DNA sequences exhibit rapid evolution,presenting diverse sizes and compositions across species.The functional significance of rye centromeric DNA sequences,particularly in centromere identity,remains unclear.In this study,we comprehensively characterized the sequence composition and organization of rye centromeres.Our findings revealed that these centromeres are primarily composed of long terminal repeat retrotransposons(LTR-RTs)and interspersed minisatellites.We systematically classified LTR-RTs into five categories,highlighting the prevalence of younger CRS1,CRS2,and CRS3 of CRSs(centromeric retrotransposons of Secale cereale)were primarily located in the core centromeres and exhibited a higher association with CENH3 nucleosomes.The minisatellites,mainly derived from retrotransposons,along with CRSs,played a pivotal role in establishing functional centromeres in rye.Additionally,we observed the formation of R-loops at specific regions of CRS1,CRS2,and CRS3,with both rye pericentromeres and centromeres exhibiting enrichment in R-loops.Notably,these R-loops selectively formed at binding regions of the CENH3 nucleosome in rye centromeres,suggesting a potential role in mediating the precise loading of CENH3 to centromeres and contributing to centromere specification.Our work provides insights into the DNA sequence composition,distribution,and potential function of R-loops in rye centromeres.This knowledge contributes valuable information to understanding the genetics and epigenetics of rye centromeres,offering implications for the development of synthetic centromeres in future plant modifications and beyond.

关 键 词：centromere LTR-RTs MINISATELLITE RYE R-loop 

分 类 号：Q343[生物学—遗传学]