UC San Diego

MicroRNAs (miRNAs) are small (~22 nucleotides) non-coding RNAs that target and repress messenger RNAs through imperfect base-pairing. First discovered in the nematode Caenorhabditis Elegans (C. elegans) (Lee et al., 1993), the microRNA pathway is conserved in many species ranging from humans to plants and plays important roles regulating genes that are critical for proper development, stress responses, and aging. (Bartel, 2018). An essential component of the microRNA pathway is the Argonaute protein. In Caenorhabditis elegans (C. elegans), the microRNA pathway involves two major Argonautes: Argonaute-like Gene 1 (ALG-1) and ALG-2. By knocking down ALG-1 and ALG-2 at different timepoints, one could shut down the entire microRNA pathway to study its effects under different biological contexts. I created and verified C. elegans strains that can rapidly degrade ALG-1 and/or ALG-2 using the auxin inducible degron 2 (AID2) system, which is detailed in chapter 2. Additionally, I tested if alg-1 mRNA might be regulated by the microRNA pathway based on noncanonical microRNA binding sites located within its 5’UTR. I found that removal of the two let-7 binding sites identified in the alg-1 5’UTR does not result in altered expression of ALG-1, which is detailed in chapter 3.