Fig. 7. Transformations in msd::LfngHA3 and Lfng^lacZ/lacZ mice. (A) Skeletal preparations of cervical vertebral columns and sterna of transgenic msd::LfngHA3 and mutant Lfng^lacZ/lacZ mice. Anterior tuberculi (asterisks) typical for C6 and the anterior-wards directed dorsal spine typical for T2 in the wild type (a) were present in msd::LfngHA3 (c,d) and Lfng^lacZ/lacZ (g,h) mice, but the number of cervical vertebrae was frequently reduced in msd::LfngHA3 and Lfng^lacZ/lacZ mice. In addition, the number of ribs attached to the sternum (seven in wild type, b) varied from six to eight in msd::LfngHA3 mice (e,f) and was often reduced to five or six in Lfng^lacz/lacZ mice (i,j). (B) Schematic overview of changes in numbers and identities of cervical vertebrae in msd::LfngHA and Lfng^lacZ/lacZ mice. Vertebrae carrying ventral processes (anterior tuberculi) and dorsal spines used as landmarks are indicated in black, the first rib-bearing vertebra is indicated in grey. In one case rudimentary ribs were found on the seventh cervical vertebra of a msd::LfngHA skeleton. (C) Summary of numbers of cervical vertebrae, ribs, and ribs attached to the sternum in msd::LfngHA3 transgenic and Lfng mutant animals. Normal numbers of skeletal elements in wild-type mice are highlighted.