title: Mapping of BnMs4 and BnRf to a common microsyntenic region of Arabidopsis thaliana chromosome 3 using intron polymorphism markers.
abstract: A recessive epistatic genic male sterile two-type line, 7365AB (Bnms3ms3ms4msRrfRf/BnMs3ms3ms4ms4RfRf), combined with the fertile interim-maintainer 7365C (Bnms3ms3ms4ms4rfrf) is an effective pollination control system in hybrid rapeseed production. We report an effective strategy used to fine map BnMs4 and BnRf. The two genes were both defined to a common microsyntenic region with Arabidopsis chromosome 3 using intron polymorphism (IP) markers developed according to Arabidopsis genome information and published genome organization of the A genome. The near-isogenic lines 7365AC (Bnms3ms3ms4ms4Rfrf/Bnms3ms3ms4ms4rfrf) of BnRf and 736512AB (Bnms3ms3Ms4ms4RfRf/Bnms3ms3ms4ms4RfRf) of BnMs4 were constructed to screen developed markers and create genetic linkage maps. Nine polymorphic IP markers (P1-P9) were identified. Of these, P2, P3, P4, and P6 were linked to both BnMs4 and BnRf with genetic distances <0.6 cM. Three simple sequence repeat markers, SR2, SR3, and SR5, were also identified by using public information. Subsequently, all markers linked to the two genes were used to compare the micro-collinearity of the regions flanking the two genes with Brassica rapa and Arabidopsis. The flanking regions showed rearrangements and inversion with fragments of different Arabidopsis chromosomes, but a high collinearity with B. rapa. This collinearity provided extremely valuable reference for map-based cloning in polyploid Brassica species. These IP markers could be exploited for comparative genomic studies within and between Brassica species, providing an economically feasible approach for molecular marker-assisted selection breeding, accelerating the process of gene cloning, and providing more direct evidence for the presence of multiple alleles between BnMs4 and BnRf.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Sub-center of Rapeseed Improvement in Wuhan, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Shengqian
authors.initials: S
authors.lastname: Xia
authors.forename: Ling
authors.initials: L
authors.lastname: Cheng
authors.forename: Feng
authors.initials: F
authors.lastname: Zu
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Dun
authors.forename: Zhengfu
authors.initials: Z
authors.lastname: Zhou
authors.forename: Bin
authors.initials: B
authors.lastname: Yi
authors.forename: Jing
authors.initials: J
authors.lastname: Wen
authors.forename: Chaozhi
authors.initials: C
authors.lastname: Ma
authors.forename: Jinxiong
authors.initials: J
authors.lastname: Shen
authors.forename: Jinxing
authors.initials: J
authors.lastname: Tu
authors.forename: Tingdong
authors.initials: T
authors.lastname: Fu
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D001483:Base Sequence; D001937:Brassica / Q000235:genetics; D002874:Chromosome Mapping / Q000379:methods*; D032461:Chromosomes, Plant / Q000235:genetics*; D017343:Genes, Plant / Q000235:genetics*; D008040:Genetic Linkage; D005819:Genetic Markers; D018745:Genome, Plant; D018895:Microsatellite Repeats; D051479:Plant Infertility / Q000235:genetics; D011123:Polyploidy; D017422:Sequence Analysis, DNA; D026801:Synteny
chemical_list: D005819:Genetic Markers