The role of small RNAs in regulating gene expression

Small noncoding RNAs are increasingly recognised as important regulators of gene expression and genome integrity across all kingdoms of life. This is particularly true in germ cells, where a diverse array of small RNAs are both genomically encoded and endogenously (endo-siRNAs) generated. Together, these small RNAs provide an important layer of complexity in gene regulation and genome organisation pathways in most metazoan species. Transgenerational inheritance of small RNAs in ciliates, plants and worms that induce specific chromatin changes have been reported and suggest that small RNAs may be important agents for stress-adaptation. While several factors have been identified in the generation of endo-siRNA in worms, flies, plants and mammalian species, there are still major gaps in understanding their biogenesis and function. Understanding the functional diversity of small RNAs, including how they establish epigenetic memory, is a fundamentally important question. C. elegans is at the forefront of understanding small RNA biology and has been the platform upon which many paradigm-shifting concepts have emerged. Using this system, we are investigating proteins that are required for normal functions of specific small RNA pathways. Our studies will help to define the molecular mechanisms that control these critical pathways.