title: Characterization and effects of the replicated flowering time gene FLC in Brassica rapa.
abstract: Functional genetic redundancy is widespread in plants and could have an important impact on phenotypic diversity if the multiple gene copies act in an additive or dosage-dependent manner. We have cloned four Brassica rapa homologs (BrFLC) of the MADS-box flowering-time regulator FLC, located at the top of chromosome 5 of Arabidopsis thaliana. Relative rate tests revealed no evidence for differential rates of evolution and the ratios of nonsynonymous-to-synonymous substitutions suggest BrFLC loci are not under strong purifying selection. BrFLC1, BrFLC2, and BrFLC3 map to genomic regions that are collinear with the top of At5, consistent with a polyploid origin. BrFLC5 maps near a junction of two collinear regions to Arabidopsis, one of which includes an FLC-like gene (AGL31). However, all BrFLC sequences are more closely related to FLC than to AGL31. BrFLC1, BrFLC2, and BrFLC5 cosegregate with flowering-time loci evaluated in populations derived by backcrossing late-flowering alleles from a biennial parent into an annual parent. Two loci segregating in a single backcross population affected flowering in a completely additive manner. Thus, replicated BrFLC genes appear to have a similar function and interact in an additive manner to modulate flowering time.
authors.affiliation: Department of Agronomy, University of Wisconsin, Madison, 53706, USA.
authors.forename: M Eric
authors.initials: ME
authors.lastname: Schranz
authors.forename: Pablo
authors.initials: P
authors.lastname: Quijada
authors.forename: Si-Bum
authors.initials: SB
authors.lastname: Sung
authors.forename: Lewis
authors.initials: L
authors.lastname: Lukens
authors.forename: Richard
authors.initials: R
authors.lastname: Amasino
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Osborn
mesh_terms: D001483:Base Sequence; D029741:Brassica rapa / Q000235:genetics* / Q000254:growth & development; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D035264:Flowers / Q000235:genetics* / Q000254:growth & development; D020440:Gene Duplication; D026161:MADS Domain Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D040641:Quantitative Trait Loci; D017422:Sequence Analysis, DNA
chemical_list: D026161:MADS Domain Proteins