Fig. 3

Fig. 3 prp encodes the zebrafish col9α1. (A) Positional cloning of prp. Top, Chromosomal view of the location of prp. Areas are not drawn to scale. (B) col9α1 and (C) col22α1 were found to be expressed in 1-day post-fertilization (dpf) embryonic finfolds (arrows) by in situ hybridization. (D) col9α1 was also highly expressed in the finfold of a 2-dpf embryo and (E) the developing caudal fin of a 15-dpf larva. Anterior, left; dorsal top. (F) A T-to-A single nucleotide change was detected in the col9α1 gene of prp which created a restriction enzyme site for ApaLI (underlined) and caused a leucine (L) to change to histidine (H). (G) RT-PCR products covering the mutation site of prp were digested by ApaLI. M, DNA markers. (H) A cross-section of a regenerating fin showing that col9α1 was expressed in cells that sandwich the forming actinotrichia (arrows; further described in Fig. 5 and Fig. 6). (I) An intron–exon map showing that col9α1 is composed of at least 36 exons (red boxes) and untranslated regions (UTRs) (white boxes). Exon 5 encodes the thrombospondin domain, where the prp mutation is found, and is also what the morpholino was designed to delete. The exon with a question mark was not clearly resolved due to a lack of a genomic sequence in this region. (J) The protein structure of zebrafish COL9α1. The protein is 942-amino-acid long and contains a thrombospondin domain (blue) on the N terminus and a long stretch of glycine-X–Y repeats (green) separated by a small gap (light blue). The prp mutation resulted in an amino-acid change from leucine (176) to histidine in the thrombospondin domain of COL9α1.