title: Variation and selection at the CAULIFLOWER floral homeotic gene accompanying the evolution of domesticated Brassica oleracea.
abstract: The evolution of plant morphologies during domestication events provides clues to the origin of crop species and the evolutionary genetics of structural diversification. The CAULIFLOWER gene, a floral regulatory locus, has been implicated in the cauliflower phenotype in both Arabidopsis thaliana and Brassica oleracea. Molecular population genetic analysis indicates that alleles carrying a nonsense mutation in exon 5 of the B. oleracea CAULIFLOWER (BoCAL) gene are segregating in both wild and domesticated B. oleracea subspecies. Alleles carrying this nonsense mutation are nearly fixed in B. oleracea ssp. botrytis (domestic cauliflower) and B. oleracea ssp. italica (broccoli), both of which show evolutionary modifications of inflorescence structures. Tests for selection indicate that the pattern of variation at this locus is consistent with positive selection at BoCAL in these two subspecies. This nonsense polymorphism, however, is also present in both B. oleracea ssp. acephala (kale) and B. oleracea ssp. oleracea (wild cabbage). These results indicate that specific alleles of BoCAL were selected by early farmers during the domestication of modified inflorescence structures in B. oleracea.
authors.affiliation: Department of Genetics, North Carolina State University, Raleigh 27695, USA. michael_purugganan@ncsu.edu
authors.forename: M D
authors.initials: MD
authors.lastname: Purugganan
authors.forename: A L
authors.initials: AL
authors.lastname: Boyles
authors.forename: J I
authors.initials: JI
authors.lastname: Suddith
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D001937:Brassica / Q000235:genetics*; D017931:DNA Primers; D005801:Genes, Homeobox; D017343:Genes, Plant; D014644:Genetic Variation; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D012641:Selection, Genetic; D012689:Sequence Homology, Nucleic Acid
chemical_list: D017931:DNA Primers