Premium
Comparative analysis of the self‐incompatibility ( S ‐) locus region of Prunus mume : identification of a pollen‐expressed F‐box gene with allelic diversity
Author(s) -
Entani Tetsuyuki,
Iwano Megumi,
Shiba Hiroshi,
Che FangSik,
Isogai Akira,
Takayama Seiji
Publication year - 2003
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1046/j.1365-2443.2003.00626.x
Subject(s) - biology , locus (genetics) , genetics , pollen , gene , haplotype , allele , botany
Background: Self‐incompatibility (SI) in the Solanaceae, Rosaceae and Scrophulariaceae is gametophytically controlled by a single polymorphic locus, termed the S ‐locus. To date, the only known S ‐locus product is a polymorphic ribonuclease, termed S ‐RNase, which is secreted by stylar tissue and thought to act as a cytotoxin that degrades the RNA of incompatible pollen tubes. However, understanding how S ‐RNase causes S ‐haplotype specific inhibition of pollen tubes has been hampered by the lack of a cloned pollen S ‐determinant gene. Results: To identify the pollen S ‐determinant gene, we investigated the genomic structure of the S ‐locus region of the S 1 ‐ and S 7 ‐haplotypes of Prunus mume (Japanese apricot), and identified 13 genes around the S‐RNase gene. Among them, only one F‐box gene, termed SLF ( S ‐locus F‐box), fulfilled the conditions for a pollen S ‐determinant gene: (i) together with the S‐RNase gene, it is located within the highly divergent genomic region of the S ‐locus, (ii) it exhibits S ‐haplotype specific diversity among three analysed S ‐haplotypes, and (iii) it is specifically expressed in pollen, but not in the styles or leaves. Conclusion: The results indicate that SLF is a prime candidate for the pollen S ‐determinant gene of SI.