Abstract
We have analysed the distribution of epigenetic marks for histone modifications at lysine residues H3 and H4, and DNA methylation, in the nuclei of mature pollen cells of the Angiosperm tree Quercus suber; a monoecious wind pollinated species with a protandrous system, and a long post-pollination period. The ultrasonic treatment developed for the isolation of pollen nuclei proved to be a fast and reliable method, preventing the interference of cell wall autofluorescence in the in situ immunolabelling assays. In contrast with previous studies on herbaceous species with short progamic phases, our results are consistent with a high level of silent (5-mC and H3K9me2) epigenetic marks on chromatin of the generative nucleus, and the prevalence of active marks (H3K9me3 and H4Kac) in the vegetative nucleus. The findings are discussed in terms of the pollination/fertilization timing strategy adopted by this plant species.
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Acknowledgments
We thank Dr. Andreas Houben (Leibniz Institute of Plant Genetics and Crop Plant Research) for kindly providing antibody against H3K9Ac. We are grateful to Augusta Barão for excellent technical assistance and Xana Castilho for her involvement with the manuscript. We also wish to thank Prof Neil Jones for his critical revision of the manuscript and editing of English. TR was supported by Fundação para a Ciência e Tecnologia with grant SFRH/BD/13319/2003.
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Communicated by Thomas Dresselhaus.
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Ribeiro, T., Viegas, W. & Morais-Cecílio, L. Epigenetic marks in the mature pollen of Quercus suber L. (Fagaceae). Sex Plant Reprod 22, 1–7 (2009). https://doi.org/10.1007/s00497-008-0083-y
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DOI: https://doi.org/10.1007/s00497-008-0083-y