title: Structural and functional comparative mapping between the Brassica A genomes in allotetraploid Brassica napus and diploid Brassica rapa.
abstract: Brassica napus (AACC genome) is an important oilseed crop that was formed by the fusion of the diploids B. rapa (AA) and B. oleracea (CC). The complete genomic sequence of the Brassica A genome will be available soon from the B. rapa genome sequencing project, but it is not clear how informative the A genome sequence in B. rapa (A(r)) will be for predicting the structure and function of the A subgenome in the allotetraploid Brassica species B. napus (A(n)). In this paper, we report the results of structural and functional comparative mapping between the A subgenomes of B. napus and B. rapa based on genetic maps that were anchored with bacterial artificial chromosomes (BACs)-sequence of B. rapa. We identified segmental conservation that represented by syntenic blocks in over one third of the A genome; meanwhile, comparative mapping of quantitative trait loci for seed quality traits identified a dozen homologous regions with conserved function in the A genome of the two species. However, several genomic rearrangement events, such as inversions, intra- and inter-chromosomal translocations, were also observed, covering totally at least 5% of the A genome, between allotetraploid B. napus and diploid B. rapa. Based on these results, the A genomes of B. rapa and B. napus are mostly functionally conserved, but caution will be necessary in applying the full sequence data from B. rapa to the B. napus as a result of genomic rearrangements in the A genome between the two species.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Congcong
authors.initials: C
authors.lastname: Jiang
authors.forename: Nirala
authors.initials: N
authors.lastname: Ramchiary
authors.forename: Yongbiao
authors.initials: Y
authors.lastname: Ma
authors.forename: Mina
authors.initials: M
authors.lastname: Jin
authors.forename: Ji
authors.initials: J
authors.lastname: Feng
authors.forename: Ruiyuan
authors.initials: R
authors.lastname: Li
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Long
authors.forename: Su Ryun
authors.initials: SR
authors.lastname: Choi
authors.forename: Chunyu
authors.initials: C
authors.lastname: Zhang
authors.forename: Wallace A
authors.initials: WA
authors.lastname: Cowling
authors.forename: Beom Seok
authors.initials: BS
authors.lastname: Park
authors.forename: Yong Pyo
authors.initials: YP
authors.lastname: Lim
authors.forename: Jinling
authors.initials: J
authors.lastname: Meng
mesh_terms: D001483:Base Sequence; D029688:Brassica napus / Q000235:genetics*; D029741:Brassica rapa / Q000235:genetics*; D002874:Chromosome Mapping; D022202:Chromosomes, Artificial, Bacterial; D032461:Chromosomes, Plant / Q000235:genetics*; D018744:DNA, Plant; D019143:Evolution, Molecular; D008040:Genetic Linkage; D018745:Genome, Plant; D040641:Quantitative Trait Loci; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D018744:DNA, Plant