Lecture 10: Developmental Genetics II

Question 1

What is the genetic maternal effect?

Answer 1

Genes transcribed into mRNAs in the ovary during egg formation and translated into proteins after fertilization. Applied to egg polarity genes.

Question 2

Which egg polarity genes establish the dorsal-ventral axis?

Answer 2

Dorsal, Cactus, Toll

Question 3

Which egg polarity genes establish the anterior-posterior axis?

Answer 3

Bicoid, Nanos, Hunchback

Question 4

What is a morphogen?

Answer 4

A protein that varies in concentration and causes different developmental responses as a result of the concentration differences.

Question 5

Which gene regulates expression of genes responsible for anterior structures and stimulates hunchback?

Answer 5

Bicoid

Question 6

Which gene regulates expression of genes responsible for posterior structures and inhibits hunchback?

Answer 6

Nanos

Question 7

What is the role of Hunchback in gene regulation?

Answer 7

Regulates transcription of genes responsible for anterior structures

Question 8

What regulates expression of segmentation genes?

Answer 8

Bicoid and Nanos protein gradients

Question 9

What are the three classes of segmentation genes?

Answer 9

Gap, Pair-rule, Segment-polarity genes

Question 10

What is the function of Gap genes?

Answer 10

Delete adjacent segments; define broad regions in the egg

Question 11

What is the function of Pair-rule genes?

Answer 11

Delete same part of pattern in every other segment; define 7 segments of egg

Question 12

What is the function of Segment-polarity genes?

Answer 12

Affect polarity of segment; defines 14 segments

Question 13

Antennapedia complex

Answer 13

Homeotic genes affecting development of head and thorax

Question 14

Bithorax genes

Answer 14

Homeotic genes affecting development of posterior thorax and abdominal segments