Fig. 2. Muscle wasting, kyphosis and enhanced lethality in mice lacking both integrin 7 and -sarcoglycan (gxi). (A) Littermate wild-type (WT) and gxi mice at 3 weeks of age. WT mice are twice the size of gxi mice by 21 days. gxi mice display reduced movement and a hopping gait with limb stiffness. (B) Radiographic images of wild-type and gxi mice showing kyphosis affecting the cervicothoracic spine in the double mutant (arrows). (C) Survival curve showing relative life span of wild-type, gsg^–/– and gxi mice. gxi mice have markedly reduced survival rates (n=10 for gsg^–/– and gxi mice, n=3 for control and Itg7^–/– mice). Integrin 7 mutants do not have reduced lethality less than 6 months of age (Mayer et al., 1997).