Abstract

RNA silencing is a term that describes the many mechanisms that organisms have evolved to regulate gene expression through the use of RNA species. Chlamydomonas reinhardtii is an attractive model for the study of RNA silencing as it potentially recapitulates the complexity of pathways found in higher plants but with experimental advantages stemming from its haploid genome, short regeneration time and the ability to synchronise the cell cycle. My research aims to investigate the diversification of RNA silencing pathways in C. reinhardtii with a particular focus on transcriptional silencing mechanisms. Initially I have been endeavouring to characterise Argonaute1, a member of a highly conserved family of RNA -binding proteins that has a central role in RNA silencing. Preliminary results suggest that Argonaute1 expression is localised in the nucleus, consistent with a role in transcriptional silencing. Future work will include analysis of small RNAs associated with Argonaute1, generation and analysis of an Argonaute1 mutant and reverse genetic approaches to directly consider the question of whether C. reinhardtii has RNA -directed transcriptional silencing mechanisms.