Project description:We report a distinctive gene-targeted RNA-directed DNA methylation (RdDM) activity in the Arabidopsis thaliana male sexual lineage that regulates gene expression in meiocytes. Loss of sexual-lineage-specific RdDM causes mis-splicing of the MPS1 gene (also known as PRD2), thereby disrupting meiosis. Our results establish a regulatory paradigm in which de novo methylation creates a cell-lineage-specific epigenetic signature that controls gene expression and contributes to cellular function in flowering plants.
Project description:Purified meiocytes from Col, Bur and taf4b Arabidopsis thaliana plants were extracted as previously described (Walker at al, 2018 Nat. Genet.), and cDNA used to produce libraries.
Project description:What are the gene expressed during meiosis pathway in Arabidopsis thalina. Comparison of total RNAs from isolated meiocytes with those isolated from root tips, and those from leaves. Comparison of transcriptomes of normal stamen (ecotype columbia) with root tips and leaves. And, comparison of transcriptomes of normal stamens (ecotype L. erecta) with stamens from sporocyteless mutant (L. erecta). Keywords: organ comparison
Project description:ra05-04_meiocytes - meiocytes - What are the gene expressed during meiosis pathway in Arabidopsis thalina. - Comparison of meiocyte transcriptome versus leaf transcriptome. Keywords: total transcriptome knowledge
Project description:What are the gene expressed during meiosis pathway in Arabidopsis thalina. Comparison of total RNAs from isolated meiocytes with those isolated from root tips, and those from leaves. Comparison of transcriptomes of normal stamen (ecotype columbia) with root tips and leaves. And, comparison of transcriptomes of normal stamens (ecotype L. erecta) with stamens from sporocyteless mutant (L. erecta). Keywords: organ comparison 11 dye-swap - CATMA arrays
Project description:ra05-04_meiocytes - meiocytes - What are the gene expressed during meiosis pathway in Arabidopsis thalina. - Comparison of meiocyte transcriptome versus leaf transcriptome. Keywords: total transcriptome knowledge 1 dye-swap - CATMA arrays
Project description:Plants do not specify their germline until late in their life cycle. Hence, the plant germline is normally specified from terminally differentiated somatic cells, though the precise mechanism(s) are unknown. We have found that male gametogenesis in maize is associated with the accumulation of distinct 21-nt phased small-interfering RNAs (phasiRNAs) generated by meiosis-associated argonaute (MAGO) proteins. MAGO1 accumulates in the epidermis of pre-meiotic anthers while MAGO2 is found in developing meiocytes. We have found that MAGO proteins are required for meiocyte development as mutants display chromosomal defects and male infertility. Furthermore, we detect the heat stress-induced activation of a distinct class of Long terminal repeat retrotransposons in the male germline of MAGO mutants. Our data suggests that MAGO proteins and the reproductive phasiRNAs play important roles protecting the germline from transposable elements during environmental stress conditions.
Project description:Meiosis is a highly complex process that underpins recombination in sexually reproducing organisms. Recent genomics studies suggest that up to several thousand genes/proteins contribute to the meiotic pathway, yet relatively few have been functionally characterised. Our understanding of the physical interactions between meiotic proteins and how the meiotic machinery interacts with other components of the cell is also limited. In this study, we used affinity proteomics targeting the meiotic chromosome axis protein, ASY1, to enrich for axis-associated proteins in Brassica oleracea anthers or meiocytes in prophase I of meiosis. LC-MS/MS analysis identified 540 proteins which co-immunoprecipitated with ASY1 in a sample-specific manner. These correspond to 485 Arabidopsis orthologues, 90% of which form a coherent predicted protein-protein interaction network which includes known and novel meiotic proteins, based on mutant analysis, but also proteins more usually associated with other cellular processes including replication and proteolysis. Our data provided new insights into the role of the chromosome axis in plant meiosis. We identified a novel axis-associated protein and showed that during prophase I, ASY1 and its interacting partner, ASY3, are extensively phosphorylated. Further studies targeting other meiotic proteins may ultimately enable the construction of a comprehensive meiosis protein-protein interaction network for higher plants.
Project description:In grasses, phased small interfering RNAs (phasiRNAs), 21- or 24-nucleotide (nt) in length, are predominantly expressed in anthers and regulate male fertility. However, their targets and mode of action on the targets remain unknown. Here we profile phasiRNA expression in premeiotic and meiotic spikelets as well as in purified male meiocytes at early prophase I, tetrads and microspores in rice. We show that 21-nt phasiRNAs are most abundant in meiocytes at early prophase I while 24-nt phasiRNAs are more abundant in tetrads and microspores. By performing highly sensitive degradome sequencing, we find that 21-nt phasiRNAs direct target mRNA cleavage in male germ cells, especially in meiocytes at early prophase I. The target genes in early prophase I meiocytes show an enrichment for carbohydrate biosynthetic and metabolic pathways. Our study provides strong evidence that 21-nt phasiRNAs act in a target-cleavage mode and may facilitate the progression of meiosis by fine-tuning carbohydrate biosynthesis and metabolism in male germ cells.