Phenotypes Associated with This Genotype

Genotype
MGI:7278768

• Allelic Composition: Sgca^tm2Kcam/Sgca^tm2Kcam
• Genetic Background: B6.129S6-Sgca^tm2Kcam/J

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

muscle

abnormal skeletal muscle morphology ( J:250485 )

• accumulation of fat infiltrates in the muscle; fat infiltrates are more abundant in gastrocnemius and diaphragm muscles than in quadriceps and tibialis anterior muscles and marker analysis suggests that fat droplets are mostly white adipose tissue

skeletal muscle fibrosis ( J:250485 )

• muscles contain extensive fibrotic infiltrates, with the diaphragm most affected

• females show a significant increase in quadriceps muscle fibrosis

dystrophic muscle ( J:250485 )

• muscles show a shift towards smaller muscle fibers, increased expression of regeneration markers, indicating regenerative fibers, an accumulation of fat infiltrates in the muscle, and impaired muscle function

abnormal muscle physiology ( J:250485 )

• muscle function is impaired and declines over time

• the tibialis anterior muscle generates a lower specific force over a wide range of stimulation intensities (10-180 Hz)

• muscles generate a higher specific force than muscles from Sgcd^tm1Mcn homozygotes

• tibialis anterior muscles repetitively stimulated at 120 Hz and stretched to 110% of their resting length show a 10-15% drop in isometric force compared to wild-type mice

behavior/neurological

decreased grip strength ( J:250485 )

• mice hang for a shorter time period than wild-type mice in the two and four limb hanging tests

• mice perform worse in the hanging tests than Sgcd^tm1Mcn homozygotes

• performance in the two limb hanging test and the four limb hanging test deteriorates over time

• however, no significant differences are seen in the rotarod test or balance beam test

homeostasis/metabolism

increased circulating creatine kinase level ( J:250485 )

respiratory system

decreased pulmonary respiratory rate ( J:250485 )

• mice show lower respiration rates at 15 and 34 weeks of age

• respiration rate is lower than in Sgcd^tm1Mcn homozygotes

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
autosomal recessive limb-girdle muscular dystrophy type 2D		DOID:0110278	OMIM:608099	J:250485