Fig. 2. Expression of bcox in zebrafish wild-type and mob^m819 embryos and larvae. (A,B,F,H,J-M,O) Lateral views, anterior towards the left; (I) dorsal view, anterior towards the left; (C) optical section of a whole-mount embryo; (G,N) sagittal and (D,E,P,Q) transverse sections. At segmentation stages, bcox is expressed along the AP axis close to the yolk boundary (A, compare with B); representative 14-somite embryos are shown. (C) A view anterior to the trunk at the level of the anterior somites and (D,E) cross-sections show expression in the vegetalmost cell layers adjacent to the yolk, corresponding to mesendoderm and mesoderm. (F) bcox expression in the head mesendoderm and in the ventral part of the optic primordia (see arrow) in a 18-somite embryo. (G) Cross-section through the optic primordium of a 21-somite embryo. (H,I) At 1 dpf, expression is found in the pharyngeal region, in individual cells around the eye, in subcutaneous cells of the head and trunk, as well as in the pectoral fin buds. (J,J') In the zebrafish mutant mob^m819 (J') bcox expression is absent in the trunk (compare with J), and (K') highly reduced in the head (compare with K), reflecting the impairments in neural crest development of this mutant (Barrallo et al., 2003). (L-N) At 2 dpf, bcox expression is found in the pharyngeal region (N), in the fin buds (L) and in single cells around the eyes (M). (O-Q) In larvae (O), bcox expression is found in the liver (P) and the gut (Q). (R) Western blot analysis of Bcox protein levels in protein extracts of zebrafish embryos. A single band with a molecular mass of 59 kDa was detected. As a control, recombinant murine Bcox (64 kDa) was used. ep, eye primordium; g, gut; hb, hindbrain; li, liver; nc, notochord; ov, otic vesicle; pe, pigment epithelium; pec, pectoral fin bud; ph, pharynx; sc, subcutaneous cells.