Fig. 4. The expression patterns of clones identified by the functional screen, examined by whole mount in situ hybridization using X. tropicalis embryos. Twenty-nine out of the 31 positive clones identified in the screen displayed identifiable in situ patterns of expression. The clones were divided into each of seven functional groups on the basis of their predicted/established function (A, transcription; B, cell signaling; C, post-transcription/translation; D, cell-cycle/apoptosis; E, metabolism; F, other functions; G, functionally unknown). The images are ordered by gene names (black). The main expression domains of each clone at all stages analyzed are indicated in red, although not all of these domains are represented in the photographs presented (cc, ciliated cells; cns, central nervous system; dt, distal tubules; e, eye; it, intermediate tubules; ms, migrating somite; n, primary neuron; ns, nephrostomes; op, olfactory pit; ov, otic vesicle; pa, pharyngeal arches; pcv, posterior cardinal veins; pn, pronephros; s, somite; vbi, ventral blood island). The numbers in each photograph indicate the developmental stage of embryos shown. Other abbreviations are: A, anterior view (dorsal is up); D, dorsal view (anterior is left); L, lateral view (anterior is left, dorsal is up).