Identification of Imprinted Genes Based on Homology: An Example of .

Genomic imprinting has drawn increasing attention in plant biology in recent years. At present, hundreds of imprinted genes have been identified in various plants, and some of them have been reported to be evolutionarily conserved in plant species. In this research, 17 candidate genes in were obtained based on the homologous imprinted genes in and other species. We further constructed reciprocal crosses of diploid strawberry () using the varieties 10-41 and 18-86 as the parents to investigate the conservation of these imprinted genes. Potentially informative single nucleotide polymorphisms (SNPs) were used as molecular markers of two parents obtained from candidate imprinted genes which have been cloned and sequenced. Meanwhile, we analyzed the SNP site variation ratios and parent-of-origin expression patterns of candidate imprinted genes at 10 days after pollination (DAP) endosperm and embryo for the hybrids of reciprocal cross, respectively. A total of five maternally expressed genes (MEGs), i.e., , -2, , , and , were identified in the endosperm, which did not show imprinting in the embryo. Finally, tissues expression analysis indicated that the five imprinted genes excluding mainly expressed in the endosperm. This is the first report on imprinted genes of , and we provide a simple and rapid method based on homologous conservation to screen imprinted genes. The present study will provide a basis for further study of function and mechanism of genomic imprinting in .