Publication Date:
2017-08-08
Description:
Reproductive barriers are commonly observed in both animals and plants, in which they maintain species integrity and contribute to speciation. This report shows that a combination of loss-of-function alleles at two duplicated loci, DUPLICATED GAMETOPHYTIC STERILITY 1 ( DGS1 ) on chromosome 4 and DGS2 on chromosome 7, causes pollen sterility in hybrid progeny derived from an interspecific cross between cultivated rice, Oryza sativa , and an Asian annual wild rice, O. nivara . Male gametes carrying the DGS1 allele from O. nivara ( DGS1-nivara s ) and the DGS2 allele from O. sativa ( DGS2-T65 s ) were sterile, but female gametes carrying the same genotype were fertile. We isolated the causal gene, which encodes a protein homologous to DNA-dependent RNA polymerase (RNAP) III subunit C4 (RPC4). RPC4 facilitates the transcription of 5S rRNAs and tRNAs. The loss-of-function alleles at DGS1-nivara s and DGS2-T65 s were caused by weak or nonexpression of RPC4 and an absence of RPC4 , respectively. Phylogenetic analysis demonstrated that gene duplication of RPC4 at DGS1 and DGS2 was a recent event that occurred after divergence of the ancestral population of Oryza from other Poaceae or during diversification of AA-genome species.
Electronic ISSN:
2160-1836
Topics:
Biology