Figure 5

Figure 5

Different grades of Chi/+ and Chi/+_LP compression fractures. Whole mount Alizarin red S stained vertebral bodies of WT (A) and mutants (B–D) visualised in bright field (left) and with fluorescence (right). Inter-individual variability and different severity levels of compression fractures are observed in three months old mutant zebrafish. Bone calli associated to fractures appear more dense than other bone elements when visualised with fluorescent light. (B) Example of a mutant Chi/+_LP showing a compression fracture affecting only one vertebral body, bone callus is visible (white arrow). (C)Chi/+_LP zebrafish displaying kyphosis associated with multiple compression fractures and evident bone calli (white arrowheads). (D) Mutant Chi/+ fish displaying severely distorted vertebrae (black arrowheads) and a collapsed vertebral body (white asterisk). The inserts in (C, D) demonstrate the identification of osteoid on whole mount-stained specimens. Black arrows indicate the presence (C) and absence (D) of osteoid in Chi/+_LP and Chi/+, respectively.