Using Gene Expression Comparisons to Reveal the Role of Transcription Factors in the Development and Evolution of a Fruit Fly Trait

The characteristics of animals develop by the use (expression) of hundreds or more genes. Each gene\u27s expression is reliant on its activation or repression at specific developmental stages and in particular cell types. For traits differing between males and females (dimorphic), some genes exhibit sex-specific expression. Proteins called transcription factors are responsible for patterned expression, as they can bind to specific DNA sequences nearby genes and from which activate or repress expression. My research studied male-specific pigmentation that evolved independently among fruit fly species from the Drosophila (D.) genus. The male-specific pigmentation of D. melanogaster is regulated by the female-specific expression of the Bab1 transcription factor. My research showed that Bab1 is expressed similarly in males and females from species that evolved dimorphic pigmentation independently from D. melanogaster. Hence, this similar dimorphic trait evolved regulation by unique transcription factors, showing how gene expression and trait evolution can have unique origins