Drosophila - Owald

Question 1

Explain the concept of the binary expression system used to create drosophila mutants

Answer 1

Fly A expresses a transcription factor (from another organism) downstream of a promoter fragment. This fragment will lead to expression of the transcription factor in specific cells only. Fly B harbors a response element that the transcription factor will bind to. Downstream you can have any gene of interest. When crossing the two flies you will get animals expressing the gene of interest specifically in the cells you want to target.

Question 2

What is important when choosing a transcription factor in the binary expression system?

Answer 2

The critical trick is to use a transcription factor from another organism that lacks a cognate factor in flies. One needs to make sure the same transcription factor binding site is not used by a homologous or unrelated fly transcription factor.

Question 3

How can Shibire-ts1 be used to study neurotransmission?

Answer 3

Shibire alleles are a set of non-complementing temperature-sensitive. Mutant animals show impaired functioning at temperatures above 29°C. The UAS-Shits1 transgene allows one to misexpress Shits1 in neurons of choice and transiently block their neurotransmission by elevating the temperature of the flies above the restrictive 29°C.