The Application of Restriction Landmark Genome Scanning Method for Surveillance of Non-Mendelian Inheritance in F1 Hybrids

We analyzed inheritance of DNA methylation in reciprocal F(1) hybrids (subsp. japonica cv. Nipponbare x subsp. indica cv. Kasalath) of rice (Oryza sativa L.) using restriction landmark genome scanning (RLGS), and detected differing RLGS spots between the parents and reciprocal F(1) hybrids. MspI/HpaII restriction sites in the DNA from these different spots were suspected to be heterozygously methylated in the Nipponbare parent. These spots segregated in F(1) plants, 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 reciprocal F(1) plants, 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.