Genome-wide high-frequency non-Mendelian loss of heterozygosity in rice

Classic Mendelian genetics declares that hybrids inherit genomic information from both male and female parents, and that alleles should be heterozygous in F1 plants. A few exceptions to this principle have been reported, but most of them are restricted to either a limited set of specific genes or specific types of alleles. Here, we show that a rice triploid and diploid hybridization resulted in stable diploid progenies, both in genotypes and phenotypes, through gene homozygosity. Furthermore, their gene homozygosity can be inherited through 8 generations, and they can convert DNA sequences of other rice varieties into their own. Molecular-marker examination confirmed that this type of genome-wide gene conversion occurred at a very high frequency. Possible mechanisms, including RNA-templated repair of double-strand DNA, are discussed.