Imagine that you are studying the control of β-globin gene expression in immature red blood cells. (Mature red blood cells contain β-globin protein but lack a nucleus and, therefore, the β-globin gene.) If you deleted a sequence of DNA outside the protein-coding region of the β-globin gene and found that this increased the rate of transcription, the deleted sequence likely functions as ________.
A) a promoter
B) a promoter-proximal element
C) an enhancer
D) a silencer
E) any of the listed functions

Question

Quizplus · Accepted Answer

The deleted sequence likely functions as a silencer because its removal resulted in increased transcription of the β-globin gene. Silencers are regulatory DNA sequences that, when bound by certain proteins, can repress the transcription of genes. Removing a silencer would relieve this repression, leading to an increase in transcription.

Imagine That You Are Studying the Control of β-Globin Gene