title: Formation of a functional maize centromere after loss of centromeric sequences and gain of ectopic sequences.
abstract: The maize (Zea mays) B centromere is composed of B centromere-specific repeats (ZmBs), centromere-specific satellite repeats (CentC), and centromeric retrotransposons of maize (CRM). Here we describe a newly formed B centromere in maize, which has lost CentC sequences and has dramatically reduced CRM and ZmBs sequences, but still retains the molecular features of functional centromeres, such as CENH3, H2A phosphorylation at Thr-133, H3 phosphorylation at Ser-10, and Thr-3 immunostaining signals. This new centromere is stable and can be transmitted to offspring through meiosis. Anti-CENH3 chromatin immunoprecipitation sequencing revealed that a 723-kb region from the short arm of chromosome 9 (9S) was involved in the formation of the new centromere. The 723-kb region, which is gene poor and enriched for transposons, contains two abundant DNA motifs. Genes in the new centromere region are still transcribed. The original 723-kb region showed a higher DNA methylation level compared with native centromeres but was not significantly changed when it was involved in new centromere formation. Our results indicate that functional centromeres may be formed without the known centromere-specific sequences, yet the maintenance of a high DNA methylation level seems to be crucial for the proper function of a new centromere.
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
authors.forename: Zhenling
authors.initials: Z
authors.lastname: Lv
authors.forename: Junling
authors.initials: J
authors.lastname: Pang
authors.forename: Yalin
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiang
authors.initials: X
authors.lastname: Guo
authors.forename: Shulan
authors.initials: S
authors.lastname: Fu
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Qianhua
authors.initials: Q
authors.lastname: Dong
authors.forename: Hua-Jun
authors.initials: HJ
authors.lastname: Wu
authors.forename: Zhi
authors.initials: Z
authors.lastname: Gao
authors.forename: Xiu-Jie
authors.initials: XJ
authors.lastname: Wang
authors.forename: Fangpu
authors.initials: F
authors.lastname: Han
mesh_terms: D002503:Centromere / Q000235:genetics*; D047369:Chromatin Immunoprecipitation; D032461:Chromosomes, Plant / Q000235:genetics; D019175:DNA Methylation; D018744:DNA, Plant / Q000235:genetics*; D018745:Genome, Plant / Q000235:genetics; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008540:Meiosis / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D018626:Retroelements / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D059467:Transcriptome; D003313:Zea mays / Q000166:cytology / Q000235:genetics* / Q000378:metabolism
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins; D018626:Retroelements