Fig. 3

Five‐dpf‐old uppercut18 zebrafish have impaired bone development. (A) mRNA levels of sox9a, runx2a, col1a1a, and col1a1b are unaltered in uppercut18 zebrafish, but transcriptional levels of col2a1a, col2a1b, osx, and col10a1a are downregulated in uppercut18 zebrafish. Each data point represents the mean of 2 technical measurements from 5 biological replicates, with highlighted mean value (line). Two‐tailed unpaired t test; *p < 0.05, **p < 0.01, and ***p < 0.001. (B) Defective cartilage development with associated impaired chondrocyte stacking (asterisk) is noted in uppercut18 zebrafish when using Tg(col2a1:mCherry) reporters. (C, D) Developmental delay of uppercut18 zebrafish in osterix (Tg[osx:Kaede]) and osteocalcin (Tg[ocn:GFP]) reporters. (C) Osterix is less expressed at the level of the ceratobranchial 5 (cb), cleithrum (c), opercle (o), and parasphenoid (p) structures; signal at the branchiostegal ray 3 (br3), hyomandibular (hm), entopterygoid (en), maxilla (m), and dentary (d) cranial head bone structures is absent in uppercut18 zebrafish. Dotted white lines represent the location of the eyes. (D) Osteocalcin is only expressed on a small part of the parasphenoid (p), whereas signal at the ceratobranchial 5 (cb), cleithrum (c), opercle (o), branchiostegal ray 3 (br3), and dentary (d) cranial head bone structures is absent in uppercut18 zebrafish. For B–D, 20 5‐dpf scrambled and crispant zebrafish were analyzed and representative samples are shown.