Mouse Genome Informatics
involves: 129S1/Sv * C57BL/6J
phenotype observed in females
phenotype observed in males
N normal phenotype
• at 16 weeks of age, homozygotes exhibit a normal peak bone mass density and are not more susceptible to ovariectomy-induced osteoporosis than control mice, as determined by dual-emission X-ray absorptiometry scanning
• at 6 months of age, intervertebral disk material is asymmetrical in shape: expanded and loose in structure at the convex side and narrowed and compressed at the concave side
• an asymmetric development of the intervertebral disk is observed at 6 months
• starting at 3-6 months of age, homozygotes exhibit an abnormal anteroposterior curvature of the spine (kyphosis)
• at 6 months of age, homozygotes display a mean thoracic angle of 93 2 vs 73C 2 observed in heterozygotes
• at 6 and 12 months of age, spinal curvature is increased due to asymmetric development of the intervertebral disk and asymmetric activity of the growth plates
• however, no apparent muscle pathology is observed
• in addition to kyphosis, homozygotes display a cervical lordosis
• however, neither scoliosis nor signs of halisteresis or compression fractures are observed
• ~30% of homozygotes display three major pathological changes of the vertebrae, including:
• anterior wedging, i.e., reduction of the anterior height of the corpora due to angulation of the terminal plates, with occasional loss of definition or irregularity of the terminal plates
• rounding or a tip-like look of the vertebrae
• an overall shortening and/or broadening of the vertebrae
• however, no pathological changes of the long bones are observed by X-ray analysis
• at 6 months of age, increased thoracic curvature is associated with a thickening and broadening of the vertebral bodies
• an asymmetric activity of the growth plates is observed at 6 months of age
• at 12 months of age, mutant spines display various degrees of irregular growth plates associated with protrusions of vertebral disk material into the cavum subarachnoidale or into the vertebral bodies

Mouse Models of Human Disease
Scheuermann Disease 181440 J:72638