• Background: The MSTN gene encodes a secreted ligand of the TGF-beta (transforming growth factor-beta) superfamily of proteins. Ligands of this family bind various TGF-beta receptors, leading to recruitment and activation of SMAD family transcription factors that regulate gene expression. The encoded preproprotein is proteolytically processed to generate each subunit of the disulfide-linked homodimer. This protein negatively regulates skeletal muscle cell proliferation and differentiation. Mutations in this gene are associated with increased skeletal muscle mass in humans and other mammals. (https://www.ncbi.nlm.nih.gov/gene/2660)
• Gene targeting strategy: The part of exon 1 to exon 3 of the mouse Gdf8 gene was knocked out in B-Gdf8 KO mice. As a result, the mouse GDF8 protein is not expressed anymore.
• Validation: Mouse GDF8 was only detectable in wild-type C57BL/6JNifdc mice but not in B-Gdf8 KO mice.

Gene targeting strategy: The part of exon 1 to exon 3 of the mouse Gdf8 gene was knocked out in B-Gdf8 KO mice. As a result, the mouse GDF8 protein is not expressed anymore.

Strain specific GDF8 expression analysis in wild-type C57BL/6JNifdc mice and B-Gdf8 KO mice by ELISA. Plasma was collected from wild-type C57BL/6JNifdc mice (+/+) and B-Gdf8 KO mice (-/-) (male, 8-week-old, n=3). Expression level of GDF8 were analyzed by ELISA (GDF-8/Myostatin Quantikine ELISA Kit: R&D, DGDF80). GDF8 was exclusively detectable in wild-type C57BL/6JNifdc mice but not in B-Gdf8 KO mice.