New evidence from Sinapis alba L. for ancestral triplication in a crucifer genome

• Published in: Genome Vol. 49; no. 3; pp. 230 - 238
• Main Authors: Nelson, M.N, Lydiate, D.J
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 01.03.2006; Canadian Science Publishing NRC Research Press
• Subjects: Brassicaceae - genetics; Chromosome Mapping; Chromosomes; Chromosomes, Plant; Crosses, Genetic; DNA probes; Evolution, Molecular; Flowers & plants; Gene Duplication; Genetic aspects; Genetic Linkage; Genetic Markers; Genome, Plant; Genomics; heterozygosity; Heterozygote; loci; Plant physiology; Polymorphism, Genetic; Polyploidy; restriction fragment length polymorphism; Sinapis - genetics; Sinapis alba
• ISSN: 0831-2796; 1480-3321
• DOI: 10.1139/g05-099

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.