Chapter 52.2, Problem 3R

Summary Introduction

To review:

The evolutionary reason for gene expression cascade, which controls species-specific mating behavior.

Introduction:

Male courtship behavior in Drosophila is an example of fixed action pattern, which does not change and it is species-specific. A single gene called double sex (dsx) controls the gene expression cascades involved in developing male and female anatomy. A different splicing of messenger ribonucleic acid (mRNA) results in different dsx products in males and females. Another single gene called fruitless (fru) controls the male courtship behavior where a female does not respond to male courtship behaviors of other species.