Molecular and genetic characterization of the S locus in Hordeum bulbosum L., a wild self-incompatible species related to cultivated barley.
Gametophytic self-incompatibility (GSI) in the grasses is controlled by a distinct two-locus genetic system governed by the multiallelic loci S and Z. We have employed diploid Hordeum bulbosum as a model species for identifying the self-incompatibility (SI) genes and for elucidating the molecular mechanisms of the two-locus SI system in the grasses. In this study, we attempted to identify S haplotype-specific cDNAs expressed in pistils and anthers at the flowering stage in H. bulbosum, using the AFLP-based mRNA fingerprinting (AMF, also called cDNA-AFLP) technique. We used the AMF-derived DNA clones as markers for fine mapping of the S locus, and found that the locus resided in a chromosomal region displaying remarkable suppression of recombination, encompassing a large physical region. Furthermore, we identified three AMF-derived markers displaying complete linkage to the S locus, although they showed no significant homology with genes of known functions. Two of these markers showed expression patterns that were specific to the reproductive organs (pistil or anther), suggesting that they could be potential candidates for the S gene.
Kakeda
Katsuyuki
K
Graduate School of Bioresources, Mie University, Tsu, 514-8507, Japan. kakeda@bio.mie-u.ac.jp
Ibuki
Toshiro
T
Suzuki
Junko
J
Tadano
Hidetaka
H
Kurita
Yuko
Y
Hanai
Yosuke
Y
Kowyama
Yasuo
Y
D000383:Agriculture; D054458:Amplified Fragment Length Polymorphism Analysis; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008040:Genetic Linkage; D005819:Genetic Markers; D006239:Haplotypes; D001467:Hordeum / Q000235:genetics*; D008969:Molecular Sequence Data; D020161:Physical Chromosome Mapping; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic / Q000235:genetics
D005819:Genetic Markers; D010940:Plant Proteins; D012333:RNA, Messenger