10. Examine Figure 17.7. below. What would be the effect on transcription if a mutation
occurred in the gene that encodes GAL3, so that no functional GAL3 was produced? (note: this
question is more about understanding the relationship between regulatory components not
necessarily Gal3 specifically) GAL4 UAS GAL80 GAL3 Galactose GAL4 GAL80 GAL3 itth
Edition
Solution
In the absence of functional GAL3 gene, inhibition of GAL4 transcription by GAL80 will not be
relieved in the presence of galactose. The genes of galactose region will not be expressed and
galactose will not be metabolized as a consequence. (For it to be working, GAL4 need to be
expressed in order to bind to UAS.)
occurred in the gene that encodes GAL3, so that no functional GAL3 was produced? (note: this
question is more about understanding the relationship between regulatory components not
necessarily Gal3 specifically) GAL4 UAS GAL80 GAL3 Galactose GAL4 GAL80 GAL3 itth
Edition
Solution
In the absence of functional GAL3 gene, inhibition of GAL4 transcription by GAL80 will not be
relieved in the presence of galactose. The genes of galactose region will not be expressed and
galactose will not be metabolized as a consequence. (For it to be working, GAL4 need to be
expressed in order to bind to UAS.)
