Diversity of centromeric repeats in two closely related wild rice species, Oryza officinalis and Oryza rhizomatis.
Oryza officinalis (CC, 2n = 24) and Oryza rhizomatis (CC, 2n = 24) belong to the Oryza genus, which contains more than 20 identified wild rice species. Although much has been known about the molecular composition and organization of centromeres in Oryza sativa, relatively little is known of its wild relatives. In the present study, we isolated and characterized a 126-bp centromeric satellite (CentO-C) from three bacterial artificial chromosomes of O. officinalis. In addition to CentO-C, low abundance of CentO satellites is also present in O. officinalis. In order to determine the chromosomal locations and distributions of CentO-C (126-bp), CentO (155 bp) and TrsC (366 bp) satellite within O. officinalis, fluorescence in situ hybridization examination was done on pachytene or metaphase I chromosomes. We found that only ten centromeres (excluding centromere 7 and 2) contain CentO-C arrays in O. officinalis, while centromere 7 comprises CentO satellites, and centromere 2 is devoid of any detectable satellites. For TrsC satellites, it was detected at multiple subtelomeric regions in O. officinalis, however, in O. rhizomatis, TrsC sequences were detected both in the four centromeric regions (CEN 3, 4, 10, 11) and the multiple subtelomeric regions. Therefore, these data reveal the evolutionary diversification pattern of centromere DNA within/or between close related species, and could provide an insight into the dynamic evolutionary processes of rice centromere.
Bao
Weidong
W
State Key Laboratory of Plant Genomics, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, PR China.
Zhang
Wenli
W
Yang
Qiuying
Q
Zhang
Yu
Y
Han
Bin
B
Gu
Minghong
M
Xue
Yongbiao
Y
Cheng
Zhukuan
Z
D001483:Base Sequence; D002503:Centromere / Q000235:genetics*; D018744:DNA, Plant / Q000235:genetics / Q000302:isolation & purification; D004276:DNA, Satellite / Q000235:genetics / Q000302:isolation & purification*; D014644:Genetic Variation; D018745:Genome, Plant; D008969:Molecular Sequence Data; D012275:Oryza / Q000145:classification / Q000235:genetics*
D018744:DNA, Plant; D004276:DNA, Satellite