Heat shock genes and the heat shock response in zebrafish embryos.

Heat shock genes exhibit complex patterns of spatial and temporal regulation during embryonic development in a wide range of organisms. Our laboratory has initiated an analysis of heat shock protein gene expression in the zebrafish, a model system that is now utilized extensively for the examination of early embryonic development of vertebrates. We have cloned members of the zebrafish hsp47, hsp70, and hsp90 gene families and shown them to be closely related to their counterparts in higher vertebrates. Whole mount in situ hybridization and Northern blot analyses have revealed that these genes are regulated in distinct spatial, temporal, and stress-specific manners. Furthermore, the tissue-specific expression patterns of the hsp47 and hsp90 alpha genes correlate closely with the expression of genes encoding known chaperone targets of Hsp47 and Hsp90 in other systems. The data raise a number of interesting questions regarding the function and regulation of these heat shock genes in zebrafish embryos during normal development and following exposure to environmental stress.