Given that maternal Bicoid activates the expression of hunchback ...

Question

Given that maternal Bicoid activates the expression of hunchback (see Figure 18.7), what would be the consequence of adding extra copies of the bicoid gene by transgenic means to a wild-type female with two copies, thus creating a female fly with three or four copies of the bicoid gene? How would hunchback expression be altered? What about the expression of other gap genes and pair-rule genes?

Accepted Answer

Hey, everyone. Let's take a look at this question together. How will the expression of hunchback protein be affected during embryonic development in female fruit flies with three or four copies of the bi coid gene. So we want to figure out if the hunchback expression would be completely suppressed, unchanged, expanded along the anterior posterior axis, or it would be reduced in the interior region but increased in the posterior region. Let's work this problem out together to try to figure out which of the following answer choices would be the most likely outcome if we have three or four copies of the bio gene. So we have this bio gene which we know that the function of this bio gene is that it regulates the expression of the punch back protein, which we note that the hunchback protein. So the punch back protein is involved in the formation of the interior posterior access during embryonic development. And so if we have three or four copies of the bio gene, which regulates the expression of the hunchback protein, which is involved in the formation of the anterior posterior axis during embryonic development, three or four copies would result an increased expression of the punch back protein. And so this increased expression of the hunchback protein in these female fruit flies would result in those higher levels of the protein in the interior region, expanding that interior domain. And so we can say that the hunchback expression would be expanded along the interior posterior axis. So answer choice C hunchback expression would be expanded along the interior posterior axis is the correct answer since that is the likely outcome if we have three or four copies of the bi coid gene, since the bitcode gene regulates the expression of the hunchback protein, which we know that the hunchback protein is involved in the formation of that anterior posterior axis during embryonic development. And three or four copies would mean that we have that increased expression of the protein resulting in the hunchback expression expanded along the anterior posterior axis, which is answer choice C I hope you found this video to be helpful. Thank you and goodbye.

Key Concepts

Bicoid Protein Function

Hunchback Gene Regulation

Gap Genes and Pair-Rule Genes Interaction

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