• CACNG1 function as a regulatory gamma subunit of voltage-gated Ca2+ channels, which was important for calcium homeostasis in various tissues.
• The exons 1-4 of mouse Cacng1 gene that encode extracellular domain and transmembrane domain are replaced by human counterparts in B-hCACNG1 mice. The sequences in exon 1 and exon 4 encoding the remaining N-terminal and C-terminal cytoplasmic portion are retained. The promoter, 5’UTR and 3’UTR region of the mouse gene are retained. The human CACNG1 expression is driven by endogenous mouse Cacng1 promoter, while mouse Cacng1 gene transcription and translation will be disrupted.
• Mouse Cacng1 mRNA was only detectable in wild-type mice. Human CACNG1 mRNA was exclusively detectable in homozygous B-hCACNG1 mice but not in wild-type mice, and the sequences were confirmed via Sanger Sequencing.
• This mouse model is useful for investigating the efficacy of CACNG1-related drugs and can also serve as a tool mouse for muscle delivery.

Gene targeting strategy for B-hCACNG1 mice. The exons 1-4 of mouse Cacng1 gene that encode extracellular domain and transmembrane domain are replaced by human counterparts in B-hCACNG1 mice. The sequences in exon 1 and exon 4 encoding the remaining N-terminal and C-terminal cytoplasmic portion are retained. The promoter, 5’UTR and 3’UTR region of the mouse gene are retained. The human CACNG1 expression is driven by endogenous mouse Cacng1 promoter, while mouse Cacng1 gene transcription and translation will be disrupted.

Strain specific analysis of CACNG1 mRNA expression in wild-type C57BL/6JNifdc mice and B-hCACNG1 mice by RT-PCR. Skeletal muscle RNA were isolated from wild-type C57BL/6JNifdc mice (+/+) and homozygous B-hCACNG1 mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human CACNG1 primers. Mouse Cacng1 mRNA was only detectable in wild-type mice. Human CACNG1 mRNA was exclusively detectable in homozygous B-hCACNG1 mice but not in wild-type mice, and the sequences were confirmed via Sanger Sequencing.

Body weight of wild-type C57BL/6JNifdc and homozygous B-hCACNG1 mice. Body weights were recorded for 6-week-old wild-type C57BL/6JNifdc mice and homozygous B-hCACNG1 mice (n=10 per sex). Values are expressed as mean ± SEM.

Complete blood count (CBC) of B-hCACNG1 mice. Values are expressed as mean ± SD.

Biochemical test of B-hCACNG1 mice. Values are expressed as mean ± SD.

The organs of male B-hCACNG1 mice (6-week-old, n=10).

The organs of female B-hCACNG1 mice (6-week-old, n=10).

Average weight of the main organs of B-hCACNG1 mice. Values are expressed as mean ± SD.

% of body weight means the ratio of organ weight to body weight.

Histopathological analysis of organs in B-hCACNG1 mice. The main organs of B-hCACNG1 mice were isolated at 6 weeks of age and analyzed with H&E staining (male, n=10; female, n=10). Results showed that no obvious abnormalities were found in all of the organs (brain, heart, lung, liver, spleen, stomach, small intestine, large intestine, quadriceps femoris, gastrocnemius, kidney, ovary and testis). Scale bar: 50 μm.