Research Group Leader
University of Cambridge
Cambridge CB2 1LR
Large proportions of eukaryotic genomes consist of transposable elements (TEs), predominantly retrotransposons. These are generally considered to be intra-chromosomal parasites. However, their periodical bursts of activity have influenced the organisation of host genomes and contributed to beneficial traits. Remarkably, a number of what turned out to be transposon-generated phenotypic innovations were selected by humans during plant domestication and breeding. Therefore, TEs can be considered as an attractive endogenous source of genetic variation. Unfortunately, there is at present no experimental/technological means to exploit this potential in a controlled fashion.
Our current research focuses on the epigenetic regulation of transcription and on molecular mechanisms contributing to formation of transgenerationally stable epigenetic sates (epialleles). This includes environmental and developmental inputs that have direct consequences for the heritable alteration transcriptional states and contribution of retrotransposons to the genome-wide landscape of epigenetic regulation.
Recently, we revealed surprisingly selective epigenetic, environmental and developmental mechanisms controlling retrotransposition in Arabidopsis. Now we build on this knowledge and plan to establish a well-controlled retrotransposition system in a crop plant and liberate the innate genetic diversity buried in silenced TEs.
Selected recent publications:
Ito H, Gaubert H, Bucher E, Mirouze M, Vaillant I, Paszkowski J. (2011) An siRNA pathway prevents transgenerational retrotransposition in plants subjected to stress. Nature 472(7341): 115-19.
Iwasaki M, Paszkowski J. (2014) Identification of genes preventing transgenerational transmission of stress-induced epigenetic states. Proc Natl Acad Sci U S A. 2014 Jun 10;111(23):8547-52. doi:10.1073/pnas.1402275111. Epub 2014 May 27.
Dapp M, Reinders J, Bédiée A, Balsera C, Bucher E, Gregory Theiler G, Granier C and Paszkowski J. (2015) Heterosis and inbreeding depression of epigenetic Arabidopsis hybrids. Nature Plants doi:10.1038/nplants.2015.92
Catoni M, Griffiths J, Becker C, Zabet NR, Bayon C, Dapp M, Lieberman-Lazarovich M, Weigel D, Paszkowski J. (2017) DNA sequence properties that predict susceptibility to epiallelic switching. EMBO Journal. pii: e201695602. doi: 10.15252/embj.201695602.
Zabet NR, Catoni M, Prischi F, Paszkowski J. (2017) Cytosine methylation at CpCpG sites triggers accumulation of non-CpG methylation in gene bodies. Nucleic Acids Res. 2017 Jan 3. pii: gkw1330. doi: 10.1093/nar/gkw1330
Selected recent reviews:
Paszkowski J. (2015) Controlled activation of retrotransposition for plant breeding. Curr Opin Biotechnol. 2015 Jan 20;32C:200-206. doi: 10.1016/j.copbio.2015.01.003. [Epub ahead of print]
Iwasaki M., Paszkowski J. (2014) Epigenetic memory in plants. EMBO J. 2014 Sep 17;33(18):1987-1998. Epub 2014 Aug 7.