Phenotypes Associated with This Genotype

Genotype
MGI:3776560

• Allelic Composition: Col1a1^m1Btlr/Col1a1^m1Btlr
• Genetic Background: C57BL/6J-Col1a1^m1Btlr

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

growth/size/body

decreased body weight ( J:253622 )

♂ • body weight is reduced 8% throughout the rapid growth period between 6 and 12 weeks of age

skeleton

abnormal femur morphology ( J:253622 )

♂ • abnormally shaped and shorter

abnormal tibia morphology ( J:253622 )

♂ • abnormally shaped and shorter

decreased length of long bones ( J:253622 )

♂

abnormal bone collagen fibril morphology ( J:253622 )

♂ • bone matrix contains sparsely-distributed collagen fibrils compared to densely-deposited collagen fibrils in wild-type bone

♂ • the type 1 collagen alpha1/alpha2 chain ratio is elevated to 3.6 compared to 2.0 in wild-type mice, suggesting the formation of some type I collagen alpha1 homotrimers

♂ • mice exhibit predominately collagen Beta11 (homotrimers of collagen I alpha1) chains compared to predominately Beta12 (heterodimers of collagen I alpha1 and alpha2) chains in wild-type mice

decreased compact bone thickness ( J:253622 )

♂ • thinner cortical bone in femurs, with cortical thickness and cortical bone area fraction reduced 14% and 24%, respectively in femurs

abnormal trabecular bone morphology ( J:253622 )

♂ • tibiae metaphysis exhibit fine trabecular bone

♂ • decrease in trabecular bone mineral density

♂ • however, the trabecular number is not different from wild-type

decreased bone mass ( J:132554 )

• homozygous mutant mice have thin bones

fragile skeleton ( J:253622 )

♂ • spinal bone fracture in mice that show abnormal locomotion

♂ • bone sections exhibit artificial fissures indicative of bone fragility

homeostasis/metabolism

decreased hydroxyproline level ( J:253622 )

♂ • bones contain less hydroxyproline indicating reduced collagen content

cardiovascular system

hemorrhage ( J:132554 )

• homozygous mutant mice have fragile tissues, evidenced by their hemorrhaging visibly from simply being grasped and picked up by the scruff

spinal hemorrhage ( J:132554 )

• homozygous mutant mice that have hemorrhaged after being picked up by the scruff exhibit a temporary paralysis that causes them to "waddle like seals" for about 8 days afterward; most retain a slightly "seal-like" gait

• uninjured homozygous mutant mice exhibit normal locomotor activity

limbs/digits/tail

abnormal autopod morphology ( J:253622 )

♂ • about 50% of mice exhibit swollen heels and foot pads, occasionally with deformed feet due to pathologic fracture

abnormal femur morphology ( J:253622 )

♂ • abnormally shaped and shorter

abnormal tibia morphology ( J:253622 )

♂ • abnormally shaped and shorter

short limbs ( J:253622 )

♂

nervous system

spinal hemorrhage ( J:132554 )

• homozygous mutant mice that have hemorrhaged after being picked up by the scruff exhibit a temporary paralysis that causes them to "waddle like seals" for about 8 days afterward; most retain a slightly "seal-like" gait

• uninjured homozygous mutant mice exhibit normal locomotor activity

behavior/neurological

abnormal locomotor behavior ( J:253622 )

♂ • abnormal locomotion

abnormal gait ( J:132554 )

• homozygous mutant mice that have hemorrhaged after being picked up by the scruff exhibit a temporary paralysis that causes them to "waddle like seals" for about 8 days afterward; most retain a slightly "seal-like" gait

• uninjured homozygous mutant mice exhibit normal locomotor activity

hindlimb paralysis ( J:132554 , J:253622 )

• homozygous mutant mice that have hemorrhaged after being picked up by the scruff exhibit a temporary paralysis that causes them to "waddle like seals" for about 8 days afterward; most retain a slightly "seal-like" gait (J:132554)

• uninjured homozygous mutant mice exhibit normal locomotor activity (J:132554)

♂ • hindlimb paralysis most likely caused by spinal bone fracture (J:253622)

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
osteogenesis imperfecta		DOID:12347	OMIM:PS166200	J:253622