Neurogenetic disseciton of memory Precise spatiotemporal regulation of genes is essential for development and homeostasis of plants and animals. Probing the function of a gene in the context of multicellular systems thus calls for an ability to manipulate gene activity in a spatially and temporally restricted way. The past three decades have seen invention of various genetic tools for precise gene manipulation, many of which were initiated in Drosophila and spread to other organisms. Arguably the most important of these was the bipartite GAL4/UAS system, which allows inducible tissue-specific expression of any given gene of interest. For instance, the concept of the "master control gene" was demonstrated using the GAL4/UAS system, whereby forced expression of the transcription factor PAX6 was found to induce formation of ectopic eyes (1). The GAL4/UAS system, however, still has limitations; although it provids certain spatial regulation, it does not offer temporal control of gene expression. In the article we are going to read this week, authors come up with a clever solution to switch on and off the activity of GAL4 at any given time. They go on to use the new method to identify a certain neuronal class in the brain that is required for memory formation. We will discuss what types of experiments would be possible with this method, and what could be the next technological breakthroughs awaiting to be made. 1. Halder G, Callaerts P, Gehring WJ
(1995). Induction of ectopic eyes by targeted expression of the eyeless gene
in Drosophila.
Science 267:1788-92. |