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The CACTA transposon Bot1 played a major role in Brassica genome divergence and gene proliferation
Author(s) -
Alix Karine,
Joets Johann,
Ryder Carol D.,
Moore Jay,
Barker Guy C.,
Bailey John P.,
King Graham J.,
Pat HeslopHarrison John S.
Publication year - 2008
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2008.03660.x
Subject(s) - brassica rapa , brassica oleracea , genome , transposable element , biology , genetics , gene , brassica , genome evolution , genomic organization , genome size , botany
Summary We isolated and characterized a Brassica C genome‐specific CACTA element, which was designated Bot1 ( Brassica oleracea transposon 1 ). After analysing phylogenetic relationships, copy numbers and sequence similarity of Bot1 and Bot1 analogues in B. oleracea (C genome) versus Brassica rapa (A genome), we concluded that Bot1 has encountered several rounds of amplification in the oleracea genome only, and has played a major role in the recent rapa and oleracea genome divergence. We performed in silico analyses of the genomic organization and internal structure of Bot1 , and established which segment of Bot1 is C‐genome specific. Our work reports a fully characterized Brassica repetitive sequence that can distinguish the Brassica A and C chromosomes in the allotetraploid Brassica napus , by fluorescent in situ hybridization. We demonstrated that Bot1 carries a host S locus‐associated SLL3 gene copy. We speculate that Bot1 was involved in the proliferation of SLL3 around the Brassica genome. The present study reinforces the assumption that transposons are a major driver of genome and gene evolution in higher plants.