Mitochondrial gene in the nuclear genome induces reproductive barrier in rice.

Hybrid incompatibility in F(1) hybrids or later generations is often observed as sterility or inviability. This incompatibility acts as postzygotic reproductive isolation, which results in the irreversible divergence of species. Here, we show that the reciprocal loss of duplicated genes encoding mitochondrial ribosomal protein L27 causes hybrid pollen sterility in F(1) hybrids of the cultivated rice Oryza sativa and its wild relative O.