期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2018
卷号：115
期号：9
页码：E1955-E1962
DOI：10.1073/pnas.1711656115
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Understanding the genetic basis of reproductive barriers between species has been a central issue in evolutionary biology. The S 1 locus in rice causes hybrid sterility and is a major reproductive barrier between two rice species, Oryza sativa and Oryza glaberrima . The O. glaberrima -derived allele (denoted S1g) on the S 1 locus causes preferential abortion of gametes with its allelic alternative (denoted S1s) in S 1 g/ S 1 s heterozygotes. Here, we used mutagenesis and screening of fertile hybrid plants to isolate a mutant with an allele, S 1 mut, which does not confer sterility in the S 1 mut/ S 1 g and S 1 mut/ S 1 s hybrids. We found that the causal mutation of the S 1 mut allele was a deletion in the peptidase-coding gene (denoted “ SSP ”) in the S 1 locus of O. glaberrima . No orthologous genes of SSP were found in the O. sativa genome. Transformation experiments indicated that the introduction of SSP in carriers of the S 1 s allele did not induce sterility. In S 1 mut/ S 1 s heterozygotes, the insertion of SSP led to sterility, suggesting that SSP complemented the loss of the functional phenotype of the mutant and that multiple factors are involved in the phenomenon. The polymorphisms caused by the lineage-specific acquisition or loss of the SSP gene were implicated in the generation of hybrid sterility. Our results demonstrated that artificial disruption of a single gene for the reproductive barrier creates a “neutral” allele, which facilitates interspecific hybridization for breeding programs.
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