Question

Methylation of DNA by the production of 5-methyl cytosine leads to:

a. None of the above

b. Gene silencing

c. Gene activation

d. All of the above

Answer 1

Ans. The correct option is b). Gene silencing

Methylation of DNA is achieved by addition of methyl group to cytosine to form 5-methylcytosine by the enzyme DNA methyltransferases. Methylation of DNA result in gene silencing. Methylation prevents the association of transcription factors to DNA and recruits the protein involved in gene silencing.

All other options are incorrect:

a). None of the above is incorrect as option b). Gene silencing is correct.

c). Gene activation is incorrect as methylation of DNA result in gene silencing.

d). All of the above is incorrect as only option b). Gene silencing is correct.