Chemical genetics: adding to the developmental biology toolbox.

Recent advances in cell and molecular biology have generated important tools to probe developmental questions. In addition, new genetic model systems such as Danio rerio now make large-scale vertebrate early developmental mutant screens feasible. Nonetheless, some developmental questions remain difficult to study because of the need for finer temporal, spatial, or tuneable control of gene function within a developmental system. New uses for old teratogens as well as novel chemical modulators of development have begun to fill this void.