RRC ID 11423
Author Kubo T, Yamagata Y, Eguchi M, Yoshimura A.
Title A novel epistatic interaction at two loci causing hybrid male sterility in an inter-subspecific cross of rice (Oryza sativa L.).
Journal Genes Genet. Syst.
Abstract Postzygotic reproductive isolation (RI) often arises in inter-subspecific crosses as well as inter-specific crosses of rice (Oryza sativa L.). To further understand the genetic architecture of the postzygotic RI, we analyzed genes causing hybrid sterility and hybrid breakdown in a rice inter-subspecific cross. Here we report hybrid male sterility caused by epistatic interaction between two novel genes, S24 and S35, which were identified on rice chromosomes 5 and 1, respectively. Genetic analysis using near-isogenic lines (NILs) carrying IR24 (ssp. indica) segments with Asominori (ssp. japonica) genetic background revealed a complicated aspect of the epistasis. Allelic interaction at the S24 locus in the heterozygous plants caused abortion of male gametes carrying the Asominori allele (S24-as) independent of the S35 genotype. On the other hand, male gametes carrying the Asominori allele at the S35 locus (S35-as) showed abortion only when the IR24 allele at the S24 locus (S24-ir) was concurrently introgressed into the S35 heterozygous plants, indicating that the sterility phenotype due to S35 was dependent on the S24 genotype through negative epistasis between S24-ir and S35-as alleles. Due to the interaction between S24 and S35, self-pollination of the double heterozygous plants produced pollen-sterile progeny carrying the S24-ir/S24-ir S35-as/S35-ir genotype in addition to the S24 heterozygous plants. This result suggests that the S35 gene might function as a modifier of S24. This study presents strong evidence for the importance of epistatic interaction as a part of the genetic architecture of hybrid sterility in rice. In addition, it suggests that diverse systems have been developed as postzygotic RI mechanisms within the rice.
Volume 83(6)
Pages 443-53
Published 2008-12
PII JST.JSTAGE/ggs/83.443
PMID 19282622
MeSH Chromosome Mapping Crosses, Genetic Epistasis, Genetic* Genes, Plant / genetics* Hybridization, Genetic* Infertility / genetics* Oryza / genetics* Phenotype Polymorphism, Restriction Fragment Length Reproduction / genetics Species Specificity
IF 0.913
Times Cited 23