Monthly Archives: July 2017

An alternative GAL4-based genetic sterile insect technique?

Here is a thought that came to me on a walk. Perhaps this could also be applied to mosquitoes to suppress wild populations.

GAL4, UAS, and GAL80 are genetic tools from yeast that are commonly used in Drosophila.

GAL4 is a protein that drives expression of genes with UAS (Upstream Activation Sequence) as a gene expression enhancer. GAL80 inhibits GAL4.

So, place the gene encoding the GAL4 protein under UAS expression. This could create a runaway positive feedback loop (GAL4 drives its own expression of more GAL4) and result in lethality.  However, set this up in Drosophila that also express GAL80 to inhibit the GAL4 from binding to UAS.

If GAL80 were expressed from a Y-chromosome only male offspring would survive to mate with the remaining females. Female-specific lethality is a powerful way to suppress a population.

This could be set up in a stable lab Drosophila stock using compound X chromosomes for X^X Y females and regular X Y males. All the Drosophila stocks, sequences, and insertion sites exist to quickly try this out.