title: Linear dominance relationship among four class-II S haplotypes in pollen is determined by the expression of SP11 in Brassica self-incompatibility.
abstract: Self-incompatibility (SI) prevents self-fertilization by rejecting pollen from plants with the same S phenotype. The Brassica SI system is controlled sporophytically by multiple alleles at the single locus, S, and dominance relationships among S haplotypes are observed in both stigma and pollen. We have identified previously five different class-II S haplotypes in Brassica campestris. Here, we performed test-crosses between S heterozygotes and their respective parental S homozygotes for four of these class-II S haplotypes, and observed a linear dominance relationship on the pollen side. To determine how this relationship is controlled, we performed RNA gel blot analyses for six S heterozygotes and their respective parental S homozygotes using the corresponding SP11 clone as a probe. In all six S heterozygotes, SP11 derived from a dominant haplotype was predominantly expressed, and SP11 derived from a recessive haplotype was repressed. Thus, the linear dominance relationship of the SI phenotype on the pollen side is regulated by the expression of SP11.
authors.affiliation: Faculty of Agriculture, Iwate University, Morioka, 020-8550 Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kakizaki
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Takada
authors.forename: Akiko
authors.initials: A
authors.lastname: Ito
authors.forename: Go
authors.initials: G
authors.lastname: Suzuki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shiba
authors.forename: Seiji
authors.initials: S
authors.lastname: Takayama
authors.forename: Akira
authors.initials: A
authors.lastname: Isogai
authors.forename: Masao
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D001937:Brassica / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D005298:Fertility / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D005799:Genes, Dominant / Q000235:genetics; D006239:Haplotypes / Q000235:genetics*; D006579:Heterozygote; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011058:Pollen / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
chemical_list: D010940:Plant Proteins; C431526:SP11 protein, Brassica