Loss of Msmo1 and Lss activity is associated with abnormal endochondral bone formation. (A-T) The hyomandibular (A,E,I,M,Q), ceratohyal (B,F,J,N,R) and hypural complex (C,D,G,H,K,L,O,P,S,T) were compared between wild type (A-D), kolnu7 (E-H), kolnu7/+:msmolnu81/+ (I-L), Tg(fabp10a:msmo1:pA)nu100;msmo1nu81 (M-P) and Tg(fabp10:lss:pA)nu101;lssnu60 (Q-T). (E-T) The endochondral bones of the mutants are compressed and irregularly shaped with ectopic ossification and fusions throughout the growth plates, marked with arrows. Images represent disarticulated whole-mount adult skeletal preparations at ∼4 months of age. Scale bars: 100μm. Tg*, Tg(fabp10:msmo1:pA)nu100; Tg**, Tg(fabp10:lss:pA)nu101. wt n=4, kolnu7 n=4, kolnu7/+:msmolnu81/+ n=4, Tg(fabp10a:msmo1:pA)nu100;msmo1nu81 n=4, Tg(fabp10:lss:pA)nu101;lssnu60 n=4.