Fig. 2.

A) Representative photograph of 4-month-old CARNS1^−/− and WT rats showing no apparent phenotypic difference between genotypes. B) Representative hematoxylin and eosin-stained histological slides of skeletal (m. soleus) and cardiac muscle depicting normal tissue morphology. C) Number of pups per mating couple during three generations, indicating that the absence of HCDs does not affect fertility. D) Body mass was similar between genotypes (WT: n = 28; CARNS1^−/−: n = 28). Mixed models: main effect of time: F(3, 50.4) = 1276.56, p < 0.0001; main effect of genotype: F(1, 55.1) = 2.57, p = 0.11; genotype*time interaction: F(3, 50.4) = 0.23, p = 0.88. *p < 0.05 vs. the previous time point (within-group effects). E-H) Physiological parameters (rectal temperature: WT n = 16, CARNS1^−/− n = 17; heart mass: WT n = 27, CARNS1^−/− n = 23; m. soleus mass: WT n = 27, CARNS1^−/− n = 23; occasional glycaemia: WT n = 16, CARNS1^−/− n = 17) were similar between genotypes. I) Distance covered in a progressive maximal running test (WT: n = 4, CARNS1^−/−: n = 6). J) The in vitro determined muscle buffering capacity (WT: n = 15, CARNS1^−/−: n = 15; ES: −0.04).