Epigenetic Repression of Male Gametophyte- Specific Genes in the Arabidopsis Sporophyte

作     者：Robert D. Hoffmann Michael G. Palmgren 

作者机构：Centre for Membrane Pumps in Cells and Disease--PUMPKIN Danish National Research Foundation Department of Plant and Environmental SciencesUniversity of Copenhagen Thorvaldsensvej 40 DK-1871 Frederiksberg Denmark 

出 版 物：《Molecular Plant》 (分子植物（英文版）)

年 卷 期：2013年第6卷第4期

页      面：1176-1186页

核心收录：

学科分类：0710[理学-生物学] 071001[理学-植物学] 07[理学] 0901[农学-作物学] 0902[农学-园艺学] 071003[理学-生理学] 

基　　金：the support of the Danish National Research Foundation through the PUMPkin Center of Excellence 

主　　题：male gametophyte epigenetics gene repression DNase I footprinting transcription factors bioinformatics. 

摘      要：Tissue formation, the identity of cells, and the functions they fulfill, are results of gene regulation. The male gametophyte of plants, pollen, is outstanding in this respect as several hundred genes expressed in pollen are not expressed in the sporophyte. How pollen-specific genes are down-regulated in the sporophyte has yet to be established. In this study, we have performed a bioinformatics analysis of publicly available genome-wide epigenetics data of sev- eral sporophytic tissues. By combining this analysis with DNase ! footprinting data, we assessed means by which the repression of pollen-specific genes in the Arabidopsis sporophyte is conferred. Our findings show that, in seedlings, the majority of pollen-specific genes are associated with histone-3 marked by mono- or trimethylation of Lys-27 （H3K27me1/ H3K27me3）, both of which are repressive markers for gene expression in the sporophyte. Analysis of DNase footprint profiles of pollen-specific genes in the sporophyte displayed closed chromatin proximal to the start codon. We describe a model of two-staged gene regulation in which a lack of nucleosome-free regions in promoters and histone modifications in open reading frames repress pollen-specific genes in the sporophyte.