lin-4 and the NRDE pathway are required to activate a transgenic lin-4 reporter but not the endogenous lin-4 locus in C. elegans
Abstract
As the founding member of the microRNA (miRNA) gene family, insights into lin-4 regulation and function have laid a conceptual foundation for countless miRNA-related studies that followed. We previously showed that a transcriptional lin-4 reporter in C. elegans was positively regulated by a lin-4-complementary element (LCE), and by lin-4 itself. In this study, we sought to (1) identify additional factors required for lin-4 reporter expression, and (2) validate the endogenous relevance of a potential positive autoregulatory mechanism of lin-4 expression. We report that all four core nuclear RNAi factors (nrde-1, nrde-2, nrde-3 and nrde-4), positively regulate lin-4 reporter expression. In contrast, endogenous lin-4 levels were largely unaffected in nrde-2;nrde-3 mutants. Further, an endogenous LCE deletion generated by CRISPR-Cas9 revealed that the LCE was also not necessary for the activity of the endogenous lin-4 promoter. Finally, mutations in mature lin-4 did not reduce primary lin-4 transcript levels. Taken together, these data indicate that under growth conditions that reveal effects at the transgenic locus, a direct, positive autoregulatory mechanism of lin-4 expression does not occur in the context of the endogenous lin-4 locus- Journal Article
- Biology and life sciences
- Genetics
- Gene expression
- Gene regulation
- MicroRNAs
- Biochemistry
- Nucleic acids
- RNA
- Non-coding RNA
- Epigenetics
- RNA interference
- Genetic interference
- Biology and Life Sciences
- Computational Biology
- Genome Complexity
- Introns
- Genomics
- Experimental Organism Systems
- Model Organisms
- Caenorhabditis Elegans
- Animal Models
- Organisms
- Eukaryota
- Animals
- Invertebrates
- Nematoda
- Caenorhabditis
- Gene Expression
- Gene Regulation
- Cell Biology
- Cell Processes
- Cell Cycle and Cell Division
- Antisense RNA