Zebrafish HSC70 promoter is a novel cold-inducible promoter from vertebrate organism

This study reports the in vivo expression research of hsc70 gene in zebrafish and the cloning of zebrafish hsc70 promoter for temperature induction study, trying to establish a cold-inducible gene expression system to replace the constitutive CMV promoter system, which we used before in our cold tolerance project.
Heat shock proteins (Hsps) are well-known stress-inducible chaperons. It had been reported can be induced by cold shock in many species from plant to vertebrate. To understand the regulation of cold-inducible gene expression, we identified the expression of zebrafish hsc70 by semi-quantitative real time-PCR, isolated the 5’-flanking sequence of zebrafish hsc70 gene and used a green fluorescent protein (GFP) for in vivo assay the promoter activity. In basal expression pattern assay, cold shock treatment resulted in a 10 folds enhanced induction of zebrafish hsc70 gene. In in vivo promoter assay, transient zebrafish showed an 2-3 folds enhanced induction. It’s clearly that we’ve identified a novel cold-inducible promoter in vertebrate.
In order to further finding out the promoter function, a series deletion of the promoter region had been preformed. After in vivo expression assay we’ve found that the shortest promoter still keeps the cold-inducibility.