We are interested in understanding the cellular and genetic mechanisms of fate specification and patterning within the zebrafish neural crest. As our starting point we are analysing the extensive selection of zebrafish pigmentation mutants isolated in Tuebingen (Kelsh et al., 1996, Development 122, 369-389; Odenthal et al, 1996, Development 122, 391-398). We are testing hypotheses as to the process of pigment cell development from the neural crest that is affected in selected mutants. Further analysis is focussed on neural crest mutations that identify genes with key roles in pigment cell specification or patterning. We aim to characterise the pigment and other neural crest phenotypes in detail, and to test directly the role that the wild type gene has on crest development using molecular, cellular, and transplantation techniques. Recently we have become interested in the use of small molecules (chemical genetics) as a technique to further these studies.