title: Epigenetic Regulation of the Sex Determination Gene MeGI in Polyploid Persimmon.
abstract: Epigenetic regulation can add a flexible layer to genetic variation, potentially enabling long-term but reversible cis-regulatory changes to an allele while maintaining its DNA sequence. Here, we present a case in which alternative epigenetic states lead to reversible sex determination in the hexaploid persimmon Diospyros kaki Previously, we elucidated the molecular mechanism of sex determination in diploid persimmon and demonstrated the action of a Y-encoded sex determinant pseudogene called OGI, which produces small RNAs targeting the autosomal gene MeGI, resulting in separate male and female individuals (dioecy). We contrast these findings with the discovery, in hexaploid persimmon, of an additional layer of regulation in the form of DNA methylation of the MeGI promoter associated with the production of both male and female flowers in genetically male trees. Consistent with this model, developing male buds exhibited higher methylation levels across the MeGI promoter than developing female flowers from either monoecious or female trees. Additionally, a DNA methylation inhibitor induced developing male buds to form feminized flowers. Concurrently, in Y-chromosome-carrying trees, the expression of OGI is silenced by the presence of a SINE (short interspersed nuclear element)-like insertion in the OGI promoter. Our findings provide an example of an adaptive scenario involving epigenetic plasticity.
authors.affiliation: Laboratory of Pomology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan takashia@kais.kyoto-u.ac.jp.|JST, PRESTO, Kawaguchi-shi, Saitama 332-0012, Japan.
authors.forename: Takashi
authors.identifier: 0000-0001-9993-8880
authors.initials: T
authors.lastname: Akagi
authors.affiliation: Department of Plant Biology and Genome Center, University of California, Davis, California 95616.
authors.forename: Isabelle M
authors.identifier: 0000-0002-6796-1119
authors.initials: IM
authors.lastname: Henry
authors.affiliation: Laboratory of Pomology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawai
authors.affiliation: Department of Plant Biology and Genome Center, University of California, Davis, California 95616.
authors.forename: Luca
authors.identifier: 0000-0003-2642-6619
authors.initials: L
authors.lastname: Comai
authors.affiliation: Laboratory of Pomology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Tao
mesh_terms: D032461:Chromosomes, Plant / Q000235:genetics; D019175:DNA Methylation / Q000235:genetics; D029788:Diospyros / Q000235:genetics*; D044127:Epigenesis, Genetic / Q000235:genetics*; D035264:Flowers / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D011123:Polyploidy; D011401:Promoter Regions, Genetic / Q000235:genetics