Describe what would happen to expression of the eve evenskip

Describe what would happen to expression of the eve (even-skipped) gene if it was mutated so that its control region could not bind to Krüppel. How would this affect the developing fruit fly?

Imagine you are cellular gene regulatory machinery, and you need to activate a gene that is currently condensed in heterochromatin. What would you have to do to turn the gene on? How would you do it?

Optimal activation of transcription of the GAL genes in yeast requires the function of two proteins: Gal4p and Gal11p. Elimination of either protein decreases activation of the GAL promoters. However, inactivation of Gal11p has the additional and dramatic effect of cell lethality. Why might elimination of Gal11p have a greater effect than elimination of Gal4p?

What is the phosphorylation state of the yeast protein Mig1 when: (a) glucose and galactose are absent; (b) galactose is present and glucose is absent; (c) glucose is present and galactose is absent; and (d) both glucose and galactose are present?

A scientist is studying the function of a type of nuclear steroid receptor protein in mouse cells. She introduces various mutations into the gene encoding the receptor protein and transfers the genes into mice. If mutations are introduced that (a) eliminate the nuclear import signal in the receptor protein or (b) alter the receptor protein surface so that the receptor can no longer interact with Hsp70 protein, how will the molecular pathway of hormone-receptor interaction be altered?

Solution

1) There are eight pair-rule genes which is responsible for forming segments in the Drosophila. And they are even-skipped, hairy, runt, fushi-tarazu, odd-skipped, paired, odd-paired, and sloppy-paired. Even-skipped, hairy, and run are primary pair-rule genes which control other secondary pair rule genes. Kruppel is a negative regulatory (repressor) of even-skipped gene. If even-skipped gene couldn\'t be repressed, its expression cannot be stopped and sub-sequent expression of other secondary pair-rule genes. It would be lethal for developing fruit fly.

2) Histone acetylation by Acetyl-transferase makes the positively charged lysine residues in histone to become neutral. This breaks the interaction between histone (lysine +) and DNA (-). And highly compact heterochromatin is converted to less compact euchromatin making the DNA accessible to transcription factors.