Small RNA Regulation of Gene Expression in Zebrafish
RNA Interference (RNAi) is an umbrella term that involves the use of small RNAs to mediate gene silencing. Silencing RNAs (siRNAs) and endogenous micro RNAs (miRNAs) use a common pathway to knockdown gene expression in a sequence-specific manner. I am studying two different mechanisms of gene silencing in zebrafish. The first is to elucidate the role that miRNAs play in regulating early development. Global analysis of miRNA expression patterns during early development showed dynamic changes in miRNA expression and my focus is to identify the mRNAs targets for specific miRNAs using gain-of-function and loss-of-function experiments. My second project is to develop a novel strategy allowing gene silencing in zebrafish in an RNAi-dependent manner. The use of siRNAs in zebrafish is controversial with numerous reports claiming nonspecific gene knockdown. I am testing a new silencing mechanism in which convergent mRNA transcripts produce nuclear double stranded RNAs that ultimately cause sequence-specific gene silencing via chromatin modification. I seek to determine whether specific histone modifications underlie gene silencing as a result of convergent transcription.