Background & current research
An understanding of the role of epigenetic processes such as DNA methylation, which can change gene expression without changing the underlying DNA sequence, is important to better understand the evolutionary trajectory of ecologically important traits. This is because of mounting evidence showing that epigenetic processes could potentially influence natural selection by changing heritable phenotypic variation (Figure 1).
Figure 1: Classic model of the influence of genetic variation on natural selection and the consequent feedback. In light of recent research, the current model propose that epigenetic variation is just as important as genetic variation on natural selection (Figure adapted from Bossdorf et al., 2007)
Figure 2: A roadside population of P. setaceum near Hopefield on the west coast of South Africa.
I have a background in genetics and completed an MSc thesis on gene silencing (an epigenetic phenomenon) in 2009. I am currently working towards my PhD degree by trying to disentangle genetic variation from epigenetic variation in natural populations of Pennisetum setaceum, a highly invasive grass previously shown to be monoclonal (Figure 2). With a known lack of genetic variation, any differences in fitness between populations within a common garden or reciprocally transplanted individuals can only be driven by epigenetic changes. I am characterizing DNA methylation, which is one of the best understood epigenetic mechanisms in plants, because it directly influences gene expression by acting as a genetic switch in promoter regions. My research aims to demonstrate whether DNA methylation changes that are artificially induced can be heritable over multiple generations. To our knowledge this is the first attempt to describe pure epigenetic population structure, i.e. in the absence of gene diversity, in natural plant populations.
Publications & conference contributions
- Du Preez, J., Stephan, D., Blignaut, M., Stander, C., Vivier, M. A., Gozszcynski, D., and Burger, J. T. (2008) The characterization of virus-based vectors for functional genomic studies in grapevine. Eighth international symposium on grapevine and biotechnology, Adelaide, Australia.
- Blignaut, M., Stephan, D., Du Preez, J., Mawasi, M. and Burger, J. T.(2009) Characterisation of ORF5 of three South African Grapevine virus A variants as pathogenicity determinant in Nicotiana benthamiana. 16th Meeting of the International Council for the Study of Virus and Virus-like Diseases of the Grapevine, Dijon, France.
- du Preez J, Stephan D, Blignaut M, Stander C, Vivier MA, Goszczynski DE, Mawassi M, Burger JT. (2010) The characterisation of virus-based vectors for functional genomic studies in grapevine. Australian Journal of Grape and Wine Research, 16, A68.
- Blignaut,M., Le Roux, J. J., Ellis, A., Esler, K. (2011) Comparative epi-genetic and genetic population structure of the highly invasive bunch grass, Pennisetum setaceum along an environmental gradient in South Africa. 11th International Conference on the Ecology and Management of Alien Plant Invasions, Szombathely, Hungary
- Blignaut, M., Stephan, D., Coetzee, B., du Preez, J., Goszczynski, D., Mawassi, M., Burger, J. T. (In preparation). Characterisation of ORF5 of three South African Grapevine virus A variants as pathogenicity determinant in Nicotiana benthamiana — Journal of General Virology or similar
- Blignaut, M., Slabbert, R., Ellis, A., Le Roux, J. J. (In preparation) Towards a universal plant AFLP protocol — Journal of Heredity or similar
