Project description:ULT1 and CLF function antagonistically as epigenetic regulators of gene expression in Arabidopsis. We sought to identity their global downstream target genes at two stages of plant development and determine their common targets. We used microarrays to determine the global gene expression programs regulated by ULT1 and FLC during vegetative and reproductive development and compared the overlap among target genes between the two proteins.
Project description:Transcriptional profiling of 16-day-old seedlings of Arabidopsis wild type control and mutants is performed using AligentM-bM-^@M-^Ys Whole Arabidopsis Gene Expression Microarray (4x44K). Two-condition experiment, seedlings of wild type control vs. Mutant sdg25, sdg26, sdg25 sdg26, atx1, sdg26 atx1, clf, sdg26 clf, ldl1 ldl2, sdg25 ldl1 ldl2 or sdg26 ldl1 ldl2. Three biological replicates: 3 control, 3 each of the ten mutants, independently grown under 12h light/ 12h dark photoperiods and harvested.
Project description:The Polycomb Group (PcG) proteins form two protein complexes, PcG Repressive Complex 1 (PRC1) and PRC2, which are key epigenetic regulators in eukaryotes. PRC2 represses gene expression by catalyzing the trimethylation of histone H3 lysine 27 (H3K27me3). In Arabidopsis (Arabidopsis thaliana), CURLY LEAF (CLF) and SWINGER (SWN) are two major H3K27 methyltransferases and core components of PRC2, playing essential roles in plant growth and development. Despite their importance, genome-wide binding profiles of CLF and SWN have not been determined and compared yet. In this study, we generated transgenic lines expressing GFP-tagged CLF/SWN under their respective native promoters and used them for ChIP-seq analyses to profile the genome-wide distributions of CLF and SWN in Arabidopsis seedlings. We also profiled and compared the global H3K27me3 levels in wild-type (WT) and PcG mutants (clf, swn, and clf swn). Our data show that CLF and SWN bind to almost the same set of genes, except that SWN has a few hundred more targets. Two short DNA sequences, the GAGA-like and Telo-box-like motifs, were found enriched in the CLF and SWN binding regions. The H3K27me3 levels in clf, but not in swn, were markedly reduced compared with WT; and the mark was undetectable in the clf swn double mutant. Further, we profiled the transcriptomes in clf, swn, and clf swn, and compared with that in WT. Thus this work provides a useful resource for the plant epigenetics community for dissecting the functions of PRC2 in plant growth and development.
Project description:Transcriptional gene silencing (TGS) in Arabidopsis is regulated by two distinct pathways, DNA methylation-dependent and –independent. ddm1 and mom1 mutants are defective in the DNA-dependent and –independent pathway, respectively. We used microarrays to detail the global changes in gene expression in the TGS mutants Keywords: TGS mutants
Project description:Chromatin remodeling factors of the Imitation Switch (ISWI) family play important roles in epigenetic regulations of gene expression in yeast and animals, whereas their function in plants remains elusive. Here we report characterization of the Arabidopsis ISWI genes CHR11 and CHR17. Double mutant chr11 chr17 displayed a dramatically reduced plant size with early flowering. In addition, epidermis of the double mutant leaves showed cell characteristics seen only in floral organs. These phenotypes resemble, at least partially, those of the Polycomb mutants curly leaf (clf) and like heterochromatin protein1 (lhp1). Microarray analysis revealed that a number of targets of the Polycomb pathway were derepressed in chr11 chr17 leaves. Furthermore, triple mutants combining chr11 chr17 with clf-29 or lhp1-6 both greatly enhanced clf-29 and lhp1-6 phenotypes, respectively. All these results strongly suggest that the ISWI family genes in Arabidopsis may function in gene silencing via the Polycomb pathway
Project description:The root epidermis of Arabidopsis provides a simple and experimentally useful model for studying the molecular basis of cell fate and differentiation. The goal of this study was to define the transcript changes in the root epidermis of mutants associated with root epidermis cell specification, including mutants that lack a visible phenotypic alteration (try, egl3, myb23, and ttg2). Transcript levels were assessed by purifying populations of root epidermal cells using fluorescence-based cell-sorting with the WER::GFP transgene. These microarray results were used to compare the effects of single and double mutants on the gene regulatory network that controls root epidermal cell fate and differentiation in Arabidopsis.
Project description:We applied the tiling arrays to study the Arabidopsis whole-genome transcriptome in Arabidopsis upf1-1 and upf3-1 mutants. Keywords: untreated condition
Project description:Arabidopsis ppi2 plants have a T-DNA insertion in atToc159 and thus display a severe defect in protein import into chloroplasts. These mutants have an albino phenotype and also are seedling lethal. We used microarrays to detail the induced genes in ppi2 plants compard to wild type plants.