title: Isolation and characterization of multiple F-box genes linked to the S9- and S10-RNase in apple (Malus × domestica Borkh.).
abstract: Using 11 consensus primer pairs designed from S-linked F-box genes of apple and Japanese pear, 10 new F-box genes (MdFBX21 to 30) were isolated from the apple cultivar 'Spartan' (S(9)S(10)). MdFBX21 to 23 and MdFBX24 to 30 were completely linked to the S(9) -RNase and S(10-)RNase, respectively, and showed pollen-specific expression and S-haplotype-specific polymorphisms. Therefore, these 10 F-box genes are good candidates for the pollen determinant of self-incompatibility in apple. Phylogenetic analysis and comparison of deduced amino acid sequences of MdFBX21 to 30 with those of 25 S-linked F-box genes previously isolated from apple showed that a deduced amino acid identity of greater than 88.0 % can be used as the tentative criterion to classify F-box genes into one type. Using this criterion, 31 of 35 F-box genes of apple were classified into 11 types (SFBB1-11). All types included F-box genes derived from S(3-) and S(9-)haplotypes, and seven types included F-box genes derived from S(3-), S(9-), and S(10-)haplotypes. Moreover, comparison of nucleotide sequences of S-RNases and multiple F-box genes among S(3-), S(9-), and S(10-)haplotypes suggested that F-box genes within each type showed high nucleotide identity regardless of the identity of the S-RNase. The large number of F-box genes as candidates for the pollen determinant and the high degree of conservation within each type are consistent with the collaborative non-self-recognition model reported for Petunia. These findings support that the collaborative non-self-recognition system also exists in apple.
authors.affiliation: Apple Research Station, NARO Institute of Fruit Tree Science, Morioka, Iwate, 020-0123, Japan. okak@affrc.go.jp
authors.forename: Kazuma
authors.initials: K
authors.lastname: Okada
authors.forename: Shigeki
authors.initials: S
authors.lastname: Moriya
authors.forename: Takashi
authors.initials: T
authors.lastname: Haji
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Abe
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D044783:F-Box Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008040:Genetic Linkage; D006239:Haplotypes; D027845:Malus / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011058:Pollen / Q000235:genetics / Q000378:metabolism; D011110:Polymorphism, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012260:Ribonucleases / Q000235:genetics* / Q000378:metabolism; D060436:Self-Incompatibility in Flowering Plants; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D044783:F-Box Proteins; D010940:Plant Proteins; D012260:Ribonucleases