Most plant species are either polyploidy or have experience polyploidization during their evolution: this indicates a selective advantage of polyploidization in plants. Polyploidization is known to affect gene expression in several ways, including epigenetic mechanisms. The best described epigenetic mechanism is DNA hypermethylation, or the predominant marking of CpG, CpCpG, CpHpHp, and CpNpG motifs in DNA. The sole methyl donor for all eukaryotes, S-adenosylmethionine, provides the methyl group essential for such Arabidopsis thaliana enzymes as CHROMOMETHYLASE 3 (CMT3) and DOMAINS REARRANGED METYLASE 2 (DRM2) responsible for marking of CpNpG motifs, and METHYLTRANSFERASE 1 (MET1), the marker of CpG islands. This study is aimed at gathering new information on the general “methylation state” in Medicago sativa, an important autopolyploid forage species affected by chromosome doubling via sexual polyploidization. 2x and 4x progenies obtained by crossing 2x plants that produce both n and 2n eggs and pollen respectively, are used. The Medicago truncatula sequence database of CpG islands in MET, CMT, DRM and DEMET (DEMETHYLTRASFERASE) family was analyzed by two different bioinformatic approaches to assess the methylation status of virtually any group of CpG sites within CpG island; this is a step toward understanding the methylation-affected biological processes. Methylase and demethylase gene expression changes were investigated by RT-qPCR and the first results will be presented. These studies can be useful to understand the basis for the polyploidy advantage in agricultural crops.
METHYLATION STATE IN MEDICAGO SATIVA POLYPLOIDIZED PLANTS: AN EPIGENETIC STUDY
DE GIOVANNI, Claudio;
2012-01-01
Abstract
Most plant species are either polyploidy or have experience polyploidization during their evolution: this indicates a selective advantage of polyploidization in plants. Polyploidization is known to affect gene expression in several ways, including epigenetic mechanisms. The best described epigenetic mechanism is DNA hypermethylation, or the predominant marking of CpG, CpCpG, CpHpHp, and CpNpG motifs in DNA. The sole methyl donor for all eukaryotes, S-adenosylmethionine, provides the methyl group essential for such Arabidopsis thaliana enzymes as CHROMOMETHYLASE 3 (CMT3) and DOMAINS REARRANGED METYLASE 2 (DRM2) responsible for marking of CpNpG motifs, and METHYLTRANSFERASE 1 (MET1), the marker of CpG islands. This study is aimed at gathering new information on the general “methylation state” in Medicago sativa, an important autopolyploid forage species affected by chromosome doubling via sexual polyploidization. 2x and 4x progenies obtained by crossing 2x plants that produce both n and 2n eggs and pollen respectively, are used. The Medicago truncatula sequence database of CpG islands in MET, CMT, DRM and DEMET (DEMETHYLTRASFERASE) family was analyzed by two different bioinformatic approaches to assess the methylation status of virtually any group of CpG sites within CpG island; this is a step toward understanding the methylation-affected biological processes. Methylase and demethylase gene expression changes were investigated by RT-qPCR and the first results will be presented. These studies can be useful to understand the basis for the polyploidy advantage in agricultural crops.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
