Question 39

(Multiple Choice)

Expression of the Even-skipped (Eve) gene in early Drosophila embryos is under the control of several transcription regulators. In one example, one of the Eve stripes is positioned near the anterior region of the embryo, and its regulatory module contains binding sites for Bicoid and Hunchback (activators) as well as Giant and Krüppel (inhibitors) such that the gene is expressed only in the region where concentrations of the two activators are high and the concentrations of the two inhibitors are low. A reporter gene can be placed under the control of this module, and it can be shown to form a stripe in the same place in the embryo as the corresponding stripe of Eve. Answer the following question(s) based on these findings.
-What would you expect to happen to the pattern of reporter expression in flies that lack the gene encoding Giant?


A) It would be expressed in all seven stripes.
B) It would be expressed in stripe 5 only.
C) It would expand to cover a broad anterior region of the embryo.
D) It would fail to express efficiently in the stripe 2 region.
E) It would be expressed throughout the whole embryo.

Answer