Question

Which type of RNA interference (RNAi) does not use Drosha and DGCR8, but instead uses the SPLICEOSOME to slice hairpin structures, resulting in pre-miRNA without extraneous sequences?

a) siRNA
b) shRNA
c) pri-miRNA
d) tRNA

Answer 1

shRNA is the type of RNA interference that uses the spliceosome instead of Drosha and DGCR8 to process hairpin structures into pre-miRNA.

Step-by-step explanation:

Among the types of RNA interference (RNAi) mechanisms, shRNA (short hairpin RNA) is the one that does not utilize Drosha and DGCR8 for its processing. Instead, shRNA goes through the splicing machinery, which makes use of the spliceosome to cleave the hairpin structures. This eventually leads to the generation of pre-miRNA molecules that are free of extraneous sequences. Unlike shRNA, siRNA is processed from long double-stranded RNA molecules without hairpin structures and is directly diced by Dicer. Pri-miRNA transcripts are initially processed by Drosha and DGCR8 to produce pre-miRNA, whereas tRNAs are involved in translation and are not part of the RNAi pathway.