Fig. 7

Expression of the genes neighboring the hoxa and hoxd clusters during zebrafish pectoral fin development. (A) Expression of the genes near the 5′ end of the hoxaa cluster. For evx1 and hibadh-a, strong expression is clearly seen within the distal region of the fin bud in a pattern similar to hoxa13a. For tax1bp1-a, little expression is seen except for a small subset of specimens (about 5%; not shown), which show an elevated level of expression in the distal region of the fin in a pattern similar to hoxa13a. (B) Expression of the genes near the 5′ end of the hoxab cluster. Similar to hoxa13b, both hibadh-b and tax1bp1-b are expressed in both proximal and distal regions of the fin bud. (C) Expression of the genes near the 5′ end of the hoxda cluster. For evx2, expression in distal regions is confined to the posterior, which is similar to its 3′ neighbor, hoxd13a. For lnp-a, low level expression is seen throughout the fin bud mesenchyme. Lateral views of left pectoral fin buds with anterior to the left in all panels. All embryos are at 48 hpf. Strong proximal staining of hibadh-a (A) and hibadh-b (B) within the fin bud represents expression within the myogenic cells. The diagram below each set of photographs represents arrangement of genes on the zebrafish genome and the direction of transcription for each gene. Distances between genes are not drawn in scale. For all genes except lnp-a, linkages and precise syntenic relationships are independently confirmed by examining large genomic clones covering the corresponding region. For lnp-a, synteny is presumed based upon its map position in radiation hybrid panels (ZFIN database) and the relative direction of transcription is tentative. chr: chromosome.