New evidence from Sinapis alba L. for ancestral triplication in a crucifer genome.
We present clear evidence of ancestral genome triplication in Sinapis alba, a close relative of the cultivated Brassica species. Exceptionally high levels of heterozygosity in the parents of an F1 intercross permitted the mapping of an estimated 87% of all detected restriction fragment length polymorphism (RFLP) loci, with each RFLP probe typically detecting 2 or 3 loci. These duplicated loci were arranged in 8 triplicated homologous linkage blocks and 2 small, duplicated, homologous linkage blocks covering the majority of the S. alba genome. Several large-scale inversions and translocations appear to have rearranged the order of loci within homologous blocks. The role of successive polyploidization events on the evolution of crucifer species is discussed.
Nelson
Matthew N
MN
School of Plant Biology, Faculty of Natural and Agricultural Sciences, University of Western Australia, 35 Stirling Highway, Crawley, 6009 WA, Australia. mnelson@plants.uwa.edu.au
Lydiate
Derek J
DJ
D019607:Brassicaceae / Q000235:genetics*; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D003433:Crosses, Genetic; D019143:Evolution, Molecular; D020440:Gene Duplication; D008040:Genetic Linkage; D005819:Genetic Markers; D018745:Genome, Plant; D006579:Heterozygote; D011110:Polymorphism, Genetic; D011123:Polyploidy; D031226:Sinapis / Q000235:genetics*
D005819:Genetic Markers