A technique enabling the controlled gene expression in targeted single cells of C-elegans

Usually, tissue specific promoters are used to examine the function of a gene of interest in vivo in transgenic fines of model organisms such as C. elegans and mice, complementing the genetic analysis with mosaic organisms. However, use of tissue specific promoters is limited by their inherent properties to drive gene expression in a restricted temporal-spatial expression pattern. It is desirable to develop techniques for regulating gene expression in a controllable way both temporally and spatially at single cell resolution. Once such techniques have been established in model organisms, they would serve as a basis for developing techniques to manipulate cellular behavior in other organisms including human. In this paper, we will first summarize previous attempts to drive gene expression at a desired time and space by using inducible promoters, in particular heat shock promoters. Then, we will examine problems encountered in the previous attempts, and report our new approach to circumvent them.