A researcher introduced many copies of a double-stranded RNA into a culture of mammalian cells and used a fluorescent probe to follow it. Later she finds that the introduced strands separate into single-stranded RNAs and she hypothesizes that the molecules is acting as an miRNA. Which of the following pieces of evidence would support her claim?
A) The degradation rate of the single strand is slower than that of other cellular mRNA's.
B) The rate of accumulation of the polypeptide encoded by the target mRNA is reduced.
C) The amount of the RNA she introduced increases due to transcription.
D) After separating the strands she introduced shut down all translation.

Question

Quizplus · Accepted Answer

The function of miRNA (microRNA) involves binding to target mRNA molecules, leading to the repression of their translation or degradation. Therefore, if the rate of accumulation of the polypeptide encoded by the target mRNA is reduced, it supports the hypothesis that the introduced RNA is acting as an miRNA, as it suggests the miRNA is effectively reducing the expression of its target gene.

A Researcher Introduced Many Copies of a Double-Stranded RNA into a Culture