Q8 - Developmental Genetics III

Question 1

What do the homeotic (HOX) genes do in Drosophila?

Answer 1

Specify anatomical features of each segment

Question 2

What are the complexes that the HOX genes are divided into? What do they do?

Answer 2

Antennapedia - specify segments of the head and upper thorax

Bithorax - specify segments of the lower thorax and abdomen

Question 3

What is the layout of the HOX genes?

Answer 3

All on one chromosome, in order from the most anterior segment to the most posterior

Question 4

What are the targets of the HOX genes? What do these do?

Answer 4

Realisator genes - form the specified tissue or organ determined by the HOX genes

Question 5

What can HOX gene mutations result in in Drosophila?

Answer 5

Mischaracterisation of segments

Question 6

Give an example of a HOX gene mutation seen in Drosophila?

Answer 6

Antennopedia gene expressed in the head - legs develop in the place of antennae

Question 7

Give an example of a HOX gene mutation seen across the animal kingdom

Answer 7

PAX gene mutations result in eye malformations with decreased size and eye sight

Question 8

Give an example of a HOX gene mutation seen in humans

Answer 8

Limb malformations