Fig. 2. Skeletal abnormalities in Tsg^-/- mice. (A) Comparison of 5-week-old wild-type and Tsg^-/- mice. The Tsg^-/- mouse is small and displays a short tail with multiple kinks. (B) X-ray of the caudal region of wild-type and Tsg^-/- adult mice. The tail vertebrae in the mutant are shorter (compare tail vertebra 7, TV7) and have less X-ray opacity (inset). (C-C') Alcian Blue preparations of E14.5 wild-type and Tsg^-/- embryos in lateral view. Note the defects in cervical and thoracic neural arch cartilages in Tsg^-/- embryos. (D-D') Alcian Blue/Alizarin Red preparations of cervical vertebrae of 2-week old wild-type and Tsg^-/- mice. The cervical neural arches are not fused dorsally in the mutant. (E-E') Alcian Blue/Alizarin Red preparations of the caudal regions of wild-type and Tsg^-/- newborn mice. Note the presence of two centers of ossification in the mutant rather than a single one in the wild-type. The seventh tail vertebra is indicated. (F,F',G,G') Skeletal elements of the tail of 2-week old wild-type and Tsg^-/- mice stained with Alcian Blue/Alizarin Red. (F') Abnormal vertebrae present a bow-tie shape and are shorter than the wild-type (compare TV7). (G') One ossification center has failed to form, producing hemi-vertebrae with misaligned articular surfaces, which cause the kinks. at, atlas; ax, axis; C3-7, cervical vertebrae 3-7; na, neural arch; T4, thoracic vertebra 4.