Function of the DEMETER DNA glycosylase in the Arabidopsis thaliana male gametophyte
| Autor: | Vera K. Schoft, Yeonhee Choi, Magdalena Mosiolek, Guen Tae Park, Marcelina García-Aguilar, Michael J. Hannon, Hisashi Tamaru, Robert L. Fischer, Adriana Machlicova, Jin Sup Park, Lucyna Slusarz, Nina Chumak |
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| Rok vydání: | 2011 |
| Předmět: |
genetic structures
DNA Plant Arabidopsis Germination Biology Genes Plant Double fertilization Genomic Imprinting Gene Expression Regulation Plant Ovule N-Glycosyl Hydrolases Gene Genetics Gametophyte Multidisciplinary Base Sequence Arabidopsis Proteins food and beverages Embryo DNA Methylation Biological Sciences Sperm eye diseases Mutation Trans-Activators Pollen Pollen tube Genomic imprinting |
| Zdroj: | Proceedings of the National Academy of Sciences. 108:8042-8047 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.1105117108 |
| Popis: | In double fertilization, the vegetative cell of the male gametophyte (pollen) germinates and forms a pollen tube that brings to the female gametophyte two sperm cells that fertilize the egg and central cell to form the embryo and endosperm, respectively. The 5-methylcytosine DNA glycosylase DEMETER (DME), expressed in the central cell, is required for maternal allele demethylation and gene imprinting in the endosperm. By contrast, little is known about the function of DME in the male gametophyte. Here we show that reduced transmission of the paternal mutant dme allele in certain ecotypes reflects, at least in part, defective pollen germination. DME RNA is detected in pollen, but not in isolated sperm cells, suggesting that DME is expressed in the vegetative cell. Bisulfite sequencing experiments show that imprinted genes ( MEA and FWA ) and a repetitive element ( Mu1a ) are hypomethylated in the vegetative cell genome compared with the sperm genome, which is a process that requires DME. Moreover, we show that MEA and FWA RNA are detectable in pollen, but not in isolated sperm cells, suggesting that their expression occurs primarily in the vegetative cell. These results suggest that DME is active and demethylates similar genes and transposons in the genomes of the vegetative and central cells in the male and female gametophytes, respectively. Although the genome of the vegetative cell does not participate in double fertilization, its DME-mediated demethylation is important for male fertility and may contribute to the reconfiguration of the methylation landscape that occurs in the vegetative cell genome. |
| Databáze: | OpenAIRE |
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