Localized Gene Induction by Infrared-Mediated Heat Shock.

ABSTRACT

Genetic manipulations are a vital instrument for the study of embryonic development where to understand how genes work, it is necessary to provoke a loss or gain of function of a particular gene in a spatial and temporal manner. In the zebrafish embryo, the Hsp70 promoter is the most commonly used tool to induce a transient global gene expression of a desired gene, in a temporal manner. However, Hsp70-driven global gene induction presents caveats when studying gene function in a tissue of interest as gene induction in the whole embryo can lead to cell-autonomous and non-cell-autonomous phenotypes. In the current article, we describe an innovative and cost effective protocol to activate Hsp70-dependent expression in a small subset of cells in the zebrafish embryo, by utilizing a localized infrared (IR) laser. Our IR laser set up can be incorporated to any microscope platform without the requirement for expensive equipment. Furthermore, our protocol allows for controlled localized induction of specific proteins under the control of the hsp70 promoter in small subsets of cells. We use the migrating zebrafish sensory lateral line primordium as a model, because of its relative simplicity and experimental accessibility; however, this technique can be applied to any tissue in the zebrafish embryo.