Determining the physical limits of the Brassica S locus by recombinational analysis.
A genetic analysis was performed to study the frequency of recombination for intervals across the Brassica S locus region. No recombination was observed between the S locus glycoprotein gene and the S receptor kinase gene in the segregating populations that we analyzed. However, a number of recombination breakpoints in regions flanking these genes were identified, allowing the construction of an integrated genetic and physical map of the genomic region encompassing one S haplotype. We identified, based on the pollination phenotype of plants homozygous for recombinant S haplotypes, a 50-kb region that encompasses all specificity functions in the S haplotype that we analyzed. Mechanisms that might operate to preserve the tight linkage of self-incompatibility specificity genes within the S locus complex are discussed in light of the relatively uniform recombination frequencies that we observed across the S locus region and of the structural heteromorphisms that characterize different S haplotypes.
Casselman
A L
AL
Department of Plant Biology, Cornell University, Ithaca, New York 14853-5908, USA.
Vrebalov
J
J
Conner
J A
JA
Singhal
A
A
Giovannoni
J
J
Nasrallah
M E
ME
Nasrallah
J B
JB
D001937:Brassica / Q000235:genetics*; D002874:Chromosome Mapping; D017343:Genes, Plant; D006239:Haplotypes; D005810:Multigene Family; D010641:Phenotype; D011058:Pollen / Q000235:genetics; D011995:Recombination, Genetic