The Fruity fruit fly

Lecture by Prof. Mark Jobling @ University of Leicester, LE1 7RH on the 05/03/2010

The tra gene is the shortened name for the transformer gene which encodes a protein called transformer. Transformer is a key regulator for sex determination; it prevents male-specific genes being expressed (produced) in female flies and vice versa.
If the female specific genes are not inhibited by the transformer, as was the case here, the male turns into a female.

This slide just shows that every somatic cell (somatic means body cell) determine sex independently. So you can have a male cell next to a female cell. In this experiment the tra gene (sex determining gene) was mutated (changed) in the brain and the fly ‘thought’ like a female even though the rest of it was a male fly (neurons are altered which are involved in senses- smell).

Neurons are components of nerves; you have lots of neurons in a single nerve. Think of miniature versions of the spine, long and carry impulses (signals) to different parts of a tissue or along the length of the body. The smells would create an impulse like in reflexes (doctor taps knee and you kick – knee jerk reaction).

NOTE:
Olfactory means smells; I think he’s saying that the mutation in the tra gene indirectly brought about a change in a protein which is affected by the tra gene product (transformer protein). Most things in the body have a chain of events before you get a final product, so you produce one protein that affects another, which affects another until you get the final product. Here an olfactory protein that detects pheromones may have been affected by the tra mutation and the fly detects pheromones like a female fly...maybe.

30/3/10 - http://arstechnica.com/science/news/2010/03/doublesex-gene-that-puts-sex-on-the-brain-of-fruitflies.ars