Analysis of early epidermal development in zebrafish.

The zebrafish (Danio rerio) is a member of the teleost (bony fish) lineage that diverged from the mammalian lineage 420 million years ago. Despite this ancient divergence, there are important similarities between the epidermis of fish and mammals. In addition, recent work suggests that the genes required for epidermal development in the zebrafish also are essential for this process in higher vertebrates, indicating that analysis of the zebrafish system will contribute to understanding mouse and human development. The zebrafish is a very useful genetic system, and many mutants with epidermal defects have been obtained in large-scale genetic screens. In addition, zebrafish embryos are transparent, develop externally, and can be collected in abundance. The aim of this chapter is to provide the researcher with basic protocols to examine gene expression, cell proliferation, and cell death in the developing zebrafish. Although only a few specific epidermal markers have been identified in the zebrafish thus far, we also provide a list of useful genes for epidermal analysis.