Ovalbumin, the major protein of egg white, is secreted by cells that line the oviduct as the bird egg moves down the oviduct. Imagine you're repeating the classic Weintraub- Groudine experiment, but with a twist: You're assaying the DNase sensitivity of the promoter regions of the fi- globin and ovalbumin genes in oviduct cells of laying hens. In this case you expect to find that
A) the fi- globin and ovalbumin promoters are equally resistant to DNase treatment.
B) the ovalbumin promoter is much more sensitive to DNase treatment.
C) the fi- globin promoter is much more sensitive to DNase treatment.
D) the fi- globin and ovalbumin promoters are equally sensitive to DNase treatment.

Question

Quizplus · Accepted Answer

Ovalbumin is specifically produced by cells lining the oviduct, whereas fi-globin is a component of hemoglobin produced in the red blood cells. Since we are assaying the DNase sensitivity of the promoter regions of these genes in oviduct cells, it is reasonable to assume that the ovalbumin promoter region would be more sensitive to DNase treatment than the fi-globin promoter region. This is because the Ovalbumin gene is actively expressed in these cells, and thus its promoter region would be more accessible (less condensed) and prone to DNase cleavage than the fi-globin promoter region.

Ovalbumin, the Major Protein of Egg White, Is Secreted by Cells