Isolation and characterization of OsDMC1, the meiosis-specific recombinase gene from rice

Abstract

For the establishment of reproducible gene targeting (GT) system in higher plants, we have been studying on the functions of homologous recombination (HR)-related genes. Among them, Dmc1 is one of the key players in meiotic recombination. Two rice DMC1 homologues (OsDMC1A and OsDMC1B) were cloned and characterized. Transgenic rice plants carrying antisense OsDMC1A/B gene produced aberrant pollens with extremely low fertility, though they did not gave any obvious phenotypes in vegetative stage. These results revealed that the OsDMC1 genes are crucial in rice gametegenesis and functional homologues of DMC1 in rice. Rice dmc1A/B mutant lines caused by Tos17 transposon insertion showed no obvious phenotype including pollen fertility, indicating that Dmc1A and Dmc1B proteins are not only highly homologous, but also functionally redundant. OsDmc1::GFP chimeric protein localized clearly on somatic chromosomes in transgenic rice and Arabidopsis. Overexpression of the DMC1 gene in Arabidopsis, however, did not affect HR rate.