Abstract

Evidence is accumulating that genetic mechanisms alone are unable explain how some traits are propagated from one generation to the next. Epigenetics is the study of heritable changes in phenotype caused by mechanisms other than changes in DNA sequence. Epigenetic modifications (for example DNA methylation and post-translational modifications of histone tails) are widely accepted as playing a critical role in the regulation of gene expression. In general, these modifications are cleared and re-established each generation. However, at some genomic loci this clearing is incomplete and the epigenetic state is transmitted to the progeny; a phenomenon that is referred to as transgenerational epigenetic inheritance. Experimental data is starting to emerge that the environment can stably influence the establishment of certain epigenetic modifications, suggesting an environmental event in one generation could affect the phenotype in subsequent generations. RNA silencing is a gene regulatory process that controls many stages during the life of a plant; for example small RNAs control numerous developmental transitions, resistance to viruses and immobilisation of transposable elements via repressive epigenetic modifications. This talk will describe experiments that have been set up to investigate the phenomenon of transgenerational epigenetic inheritance in Arabidopsis and whether or not small RNAs play a role.