Phenotypes associated with this allele

• Allele Symbol: Col1a1^em1Nju
• Allele Name: endonuclease-mediated mutation 1, Model Animal Research Center of Nanjing University
• Allele ID: MGI:7863770
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Col1a1^em1Nju/Col1a1^em1Nju	C57BL/6-Col1a1^em1Nju	MGI:7863804
ht2	Col1a1^em1Nju/Col1a1^+	C57BL/6-Col1a1^em1Nju	MGI:7863810

Genotype
MGI:7863804

hm1

• Allelic Composition: Col1a1^em1Nju/Col1a1^em1Nju
• Genetic Background: C57BL/6-Col1a1^em1Nju

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

mortality/aging

prenatal lethality, complete penetrance ( J:358220 )

• no homozygotes are obtained

Genotype
MGI:7863810

ht2

• Allelic Composition: Col1a1^em1Nju/Col1a1⁺
• Genetic Background: C57BL/6-Col1a1^em1Nju

growth/size/body

decreased body weight ( J:358220 )

• body weight is significantly reduced from around 5 weeks of age

slow postnatal weight gain ( J:358220 )

• mice exhibit reduced weight gain from around 5 weeks of age

skeleton

abnormal bone structure ( J:358220 )

• bone surface area/bone volume ratio in femurs is increased (nearly doubled) at 8 weeks but not 20 weeks of age

impaired osteoblast differentiation ( J:358220 )

• adipose-derived mesenchymal stem cells treated with osteogenic induction medium show reduced osteoblast differentiation

decreased bone mineral content ( J:358220 )

• bone mineral content is reduced at 8 and 20 weeks of age

decreased bone mineral density ( J:358220 )

• bone mineral density is reduced at 8 and 20 weeks of age, however mineralization does improve with aging

decreased trabecular bone volume ( J:358220 )

• trabecular bone volume/total volume ratio in femurs is reduced by about half at 8 and 20 weeks of age

• however, no differences in cortical bone values are seen

decreased bone trabecula number ( J:358220 )

• a small reduction in trabecular number in femurs at 20 weeks of age, but not at 8 weeks

increased bone trabecular spacing ( J:358220 )

• trabecular spacing of femurs is increased at 8 and 20 weeks of age

decreased trabecular bone thickness ( J:358220 )

• trabecular thickness of femurs is reduced at 8 weeks of age and to a lesser degree at 20 weeks of age

osteoporosis ( J:358220 )

decreased bone ossification ( J:358220 )

• lower serum PINP levels indicating reduction in bone osteogenesis

increased bone resorption ( J:358220 )

• lower serum PINP and higher CTX-I levels indicating weakened collagen secretion and unusually active degradation; PINP production reduces but CTX-I level remains stable with age, indicating a sustained bone absorption

• both the percentage and number of TRAP+ osteoclasts on the trabecular surface is increased indicating continuously active osteoclasts

decreased femur stiffness ( J:358220 )

• femurs exhibit decreased stiffness at 8 and 20 weeks of age

• while stiffness increases by 20 weeks of age, stiffness is still smaller than in wild-type at this age

decreased bone strength ( J:358220 )

• lower mechanical strength

decreased femur maximal load ( J:358220 )

• femurs bare a smaller maximum load

• while maximum load increases by 20 weeks of age, they are still smaller than in wild-type at this age

decreased energy dissipated prior to femur fracture ( J:358220 )

• femurs exhibit reduced post-yield displacement and plasticity

fragile skeleton ( J:358220 )

• femurs exhibit lower post-yield displacement, post-yield energy, and work-to-fracture indicating more brittle bones

• however, no spontaneous fractures are seen

cellular

impaired osteoblast differentiation ( J:358220 )

• adipose-derived mesenchymal stem cells treated with osteogenic induction medium show reduced osteoblast differentiation

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
osteogenesis imperfecta type 1		DOID:0110334	OMIM:166200	J:358220