In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 105, No. 32 ( 2008-08-12), p. 11436-11441
Abstract:
Hybrid sterility is a major form of postzygotic reproductive isolation. Although reproductive isolation has been a key issue in evolutionary biology for many decades in a wide range of organisms, only very recently a few genes for reproductive isolation were identified. The Asian cultivated rice ( Oryza sativa L.) is divided into two subspecies, indica and japonica . Hybrids between indica and japonica varieties are usually highly sterile. A special group of rice germplasm, referred to as wide-compatibility varieties, is able to produce highly fertile hybrids when crossed to both indica and japonica . In this study, we cloned S5 , a major locus for indica–japonica hybrid sterility and wide compatibility, using a map-based cloning approach. We show that S5 encodes an aspartic protease conditioning embryo-sac fertility. The indica ( S5 -i) and japonica ( S5 -j) alleles differ by two nucleotides. The wide compatibility gene ( S5 -n) has a large deletion in the N terminus of the predicted S5 protein, causing subcellular mislocalization of the protein, and thus is presumably nonfunctional. This triallelic system has a profound implication in the evolution and artificial breeding of cultivated rice. Genetic differentiation between indica and japonica would have been enforced because of the reproductive barrier caused by S5 -i and S5 -j, and species coherence would have been maintained by gene flow enabled by the wide compatibility gene.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.0804761105
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2008
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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