Development of snRNA reporter genes to investigate the role of PHAX in snRNP biogenesis (2015)

Undergraduate: Rita Meganck

Faculty Advisor: Gregory Matera
Department: Biology

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Sm-class small nuclear RNAs (snRNAs) are major components of the spliceosomal complex, which is required for the splicing of introns in eukaryotic pre-mRNAs. In order to assemble into biologically active small nuclear ribonucleoprotein (snRNP) complexes, the snRNAs must exit the nucleus, which requires the snRNA export adaptor, PHAX. Mutations in this gene would be expected to be lethal, as snRNPs cannot properly assemble. However, about one quarter of flies with a homozygous null mutation in PHAX survive to adulthood. To investigate this effect, we created reporter genes of the snRNAs U1, U2, U4, U6, and LU by replacing the coding region of each gene with the fluorescent RNA aptamers Broccoli and Mango. Transgenic flies will be created that contain the reporter gene and will be crossed to PHAX mutants. These will be imaged to determine if snRNAs are able to leave the nucleus in the absence of PHAX. As most eukaryotic species export their snRNAs into the cytoplasm prior to snRNP assembly, the results found here should provide insight into the mechanisms of snRNA transport.