Question

You transfer the DAM gene to the telomere of yeast. What will be your expected result?

(a) Methylation at the A sites in specific sequence

(b) Methylation at the C sites in specific sequence

(c) No methylation at the A sites in specific sequence

(d) No methylation at the C sites in specific sequence

The question was asked at a job interview.

I want to ask this question from Transcription in Eukaryotes : Gene Silencing at Telomere topic in section Gene Expression : Transcription Prokaryotes of Cytogenetics

Answer 1

The correct answer is (c) No methylation at the A sites in specific sequence

The best explanation: DAM is a methylase that methylates the A of GATC sequence. When expressed in Yeast it methylated the yeast DNA, however, in telomere the expression is blocked by the telomere silencing effect. Thus, we don’t get methylated DNA.