The Application of Restriction Landmark Genome Scanning Method for Surveillance of Non-Mendelian Inheritance inF1Hybrids

We analyzed inheritance of DNA methylation in reciprocalF1hybrids (subsp.japonicacv. Nipponbare×subsp.indicacv. Kasalath) of rice (Oryza sativaL.) using restriction landmark genome scanning (RLGS), and detected differing RLGS spots between the parents and reciprocalF1hybrids.MspI/HpaII restriction sites in the DNA from these different spots were suspected to be heterozygously methylated in the Nipponbare parent. These spots segregated inF1plants, but did not segregate in selfed progeny of Nipponbare, showing non-Mendelian inheritance of the methylation status. As a result of RT-PCR and sequencing, a specific allele of the gene nearest to the methylated sites was expressed in reciprocalF1plants, showing evidence of biased allelic expression. These results show the applicability of RLGS for scanning of non-Mendelian inheritance of DNA methylation and biased allelic expression.