Characterization of the centromere and peri-centromere retrotransposons in Brassica rapa and their distribution in related Brassica species

Ki Byung Lim, Tae Jin Yang, Yoon Jung Hwang, Jung Sun Kim, Jee Young Park, Soo Jin Kwon, Jin A. Kim, Beom Soon Choi, Myung Ho Lim, Mina Jin, Ho Il Kim, Hans De Jong, Ian Bancroft, Yong Pyo Lim, Beom Seok Park

Research output: Contribution to journalArticlepeer-review

96 Scopus citations

Abstract

We report the identification and characterization of the major repeats in the centromeric and peri-centromeric heterochromatin of Brassica rapa. The analysis involved the characterization of 88 629 bacterial artificial chromosomes (BAC) end sequences and the complete sequences of two BAC clones. We identified centromere-specific retrotransposons of Brassica (CRB) and various peri-centromere-specific retrotransposons (PCRBr). Three copies of the CRB were identified in one BAC clone as nested insertions within a tandem array of 24 copies of a 176 bp centromeric repeat, CentBr. A complex mosaic structure consisting of nine PCRBr elements and large blocks of 238 bp degenerate tandem repeats (TR238) were found in or near a derivative of 5S-25S rDNA sequences. The chromosomal positions of selected repeats were determined using in situ hybridization. These revealed that CRB is a major component of all centromeres in three diploid Brassica species and their allotetraploid relatives. However, CentBr was not detected in the most distantly related of the diploid species analyzed, B. nigra. PCRBr and TR238 were found to be major components in the peri-centromeric heterochromatin blocks of four chromosomes of B. rapa. These repetitive elements were not identified in B. oleracea or B. nigra, indicating that they are A-genome-specific.

Original languageEnglish
Pages (from-to)173-183
Number of pages11
JournalPlant Journal
Volume49
Issue number2
DOIs
StatePublished - Jan 2007

Keywords

  • Centromere retrotransposon
  • Centromere tandem repeat
  • FISH
  • Genome evolution
  • Heterochromatin
  • Peri-centromere retrotransposon

Fingerprint

Dive into the research topics of 'Characterization of the centromere and peri-centromere retrotransposons in Brassica rapa and their distribution in related Brassica species'. Together they form a unique fingerprint.

Cite this