Phenotypes associated with this allele

• Allele Symbol: Col12a1^tm1Debi
• Allele Name: targeted mutation 1, David E Birk
• Allele ID: MGI:5141135
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Col12a1^tm1Debi/Col12a1^tm1Debi	involves: 129 * C57BL/6	MGI:5141226
hm2	Col12a1^tm1Debi/Col12a1^tm1Debi	Not Specified	MGI:5576977

Genotype
MGI:5141226

hm1

• Allelic Composition: Col12a1^tm1Debi/Col12a1^tm1Debi
• Genetic Background: involves: 129 * C57BL/6

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

Kyphosis in 5 month old Col12a1^tm1Debi/Col12a1^tm1Debi mice

mortality/aging

perinatal lethality, incomplete penetrance ( J:174217 )

• Background Sensitivity: increased perinatal lethality on a background heavily weighted to C57BL/6

• Background Sensitivity: further studies done in a genetic background heavily weighted to 129

growth/size/body

decreased body weight ( J:174217 )

• significantly reduced body weight at 30 days of age

skeleton

skeleton phenotype ( J:174217 )

N • osteoclast numbers are similar to controls

abnormal skeleton morphology ( J:174217 )

abnormal femur morphology ( J:174217 )

decreased diameter of femur ( J:174217 )

• smaller diameters

• reduced tissue area/bone length

short femur ( J:174217 )

abnormal vertebral column morphology ( J:174217 )

kyphosis ( J:174217 )

• abnormally curved spines

abnormal vertebral spinous process morphology ( J:174217 )

• double spinous processes

abnormal bone structure ( J:174217 )

abnormal compact bone morphology ( J:174217 )

• femur has proportionally less cortical bone mass than controls

• cortical thickness is reduced about 10%

abnormal osteoblast morphology ( J:174217 )

• osteoblasts are poorly aligned and disorganized relative to the cortical bone surface

• osteoblasts have poorly organized actin cytoskeletons

• fewer osteoblast/osteocyte processes

• large intracellular spaces

abnormal skeleton development ( J:174217 )

abnormal cartilage development ( J:174217 )

• birefringent collagen fibers are sparse and disorganized in the bone matrix

abnormal skeleton physiology ( J:174217 )

abnormal osteoblast physiology ( J:174217 )

• osteoblasts from 30 day old mice in culture form mineralized nodules more slowly and in lower numbers than controls

• difference is no longer significant after day 28 of culture

• gap junction-mediated intercellular communication is reduced

decreased bone mineralization ( J:174217 )

• lower mineral apposition rate and mineralized surface/total bone surface in 30 day old mice

decreased bone ossification ( J:174217 )

• lower bone formation rate in 30 day old mice

decreased bone strength ( J:174217 )

• maximum load to failure, bone robustness, stiffness are all reduced

limbs/digits/tail

abnormal femur morphology ( J:174217 )

decreased diameter of femur ( J:174217 )

• smaller diameters

• reduced tissue area/bone length

short femur ( J:174217 )

cellular

abnormal actin cytoskeleton morphology ( J:174217 )

• osteoblasts have poorly organized actin cytoskeletons

abnormal osteoblast physiology ( J:174217 )

• osteoblasts from 30 day old mice in culture form mineralized nodules more slowly and in lower numbers than controls

• difference is no longer significant after day 28 of culture

• gap junction-mediated intercellular communication is reduced

Genotype
MGI:5576977

hm2

• Allelic Composition: Col12a1^tm1Debi/Col12a1^tm1Debi
• Genetic Background: Not Specified

behavior/neurological

limb grasping ( J:209074 )

• decrease in hindlimb splaying when on tail suspension

decreased grip strength ( J:209074 )

muscle

abnormal sarcolemma morphology ( J:209074 )

• contour of the sarcolemma of individual muscle fibers has a more wavy appearance at P3 and P30

abnormal skeletal muscle morphology ( J:209074 )

• soleus shows an increase in fast fiber type IIa and a decrease in slow fiber type I

• tibialis anterior muscle shows an increase of fiber type IIb and decrease of fiber type IIx

• distribution of large collagen fibrils in the endomysium is different from wild-type, with fibrils more located in the middle of the endomysium instead of in close proximity to the basement membrane

abnormal quadriceps morphology ( J:209074 )

• mild increase in central nucleation in the quadriceps muscle, however no degeneration and regeneration are seen

decreased skeletal muscle weight ( J:209074 )

• absolute weights of tibialis anterior, gastrocnemius, quadriceps, and extensor digitorum longus muscles are lower

abnormal muscle physiology ( J:209074 )

• isometric tetanic force production is depressed by 18% in extensor digitorum longus (EDL) muscles, leading to a lower specific force

• EDL shows less force drop on the eccentric contraction paradigm in the muscle

• EDL shows a decrease in passive force generation, particularly at higher amplitudes of stretch

skeleton

kyphoscoliosis ( J:209074 )

abnormal vertebral spinous process morphology ( J:209074 )

• doubling of the spinous process

limbs/digits/tail

abnormal quadriceps morphology ( J:209074 )

• mild increase in central nucleation in the quadriceps muscle, however no degeneration and regeneration are seen