Question

While studying the transcripts in vitro you observe that other than the longer transcripts there are some short stretches of RNA oligomer produced as well. You repeat the experiment several times but these oligomers seem to persist. What is the possible explanation?

(a) Procedural error

(b) They are the un-ligated oligomers of lagging strand

(c) Experimental artifact

(d) Normal occurrence

This question was addressed to me in class test.

Enquiry is from Transcription in Prokaryotes : Elongation topic in section Gene Expression : Transcription Prokaryotes of Cytogenetics

Answer 1

Correct answer is (c) Experimental artifact

To explain: These short oligomers are abortive transcripts produced by the RNA polymerase before it leaves the promoter. There is no lagging strand in RNA and since the experiment is repeated several times with caution the other justifications are rules out.