1. A MSTN Del73C mutation with FGF5 knockout sheep by CRISPR/Cas9 promotes skeletal muscle myofiber hyperplasia.
- Author
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Chen MM, Zhao Y, Yu K, Xu XL, Zhang XS, Zhang JL, Wu SJ, Liu ZM, Yuan YM, Guo XF, Qi SY, Yi G, Wang SQ, Li HX, Wu AW, Liu GS, Deng SL, Han HB, Lv FH, Lian D, and Lian ZX
- Subjects
- Animals, Sheep, Muscle Fibers, Skeletal metabolism, Muscle Fibers, Skeletal pathology, Mutation, Gene Knockout Techniques, Hyperplasia genetics, Muscle, Skeletal metabolism, Muscle, Skeletal pathology, Myostatin genetics, Myostatin metabolism, CRISPR-Cas Systems, Fibroblast Growth Factor 5 genetics, Fibroblast Growth Factor 5 metabolism
- Abstract
Mutations in the well-known Myostatin ( MSTN ) produce a 'double-muscle' phenotype, which makes it commercially invaluable for improving livestock meat production and providing high-quality protein for humans. However, mutations at different loci of the MSTN often produce a variety of different phenotypes. In the current study, we increased the delivery ratio of Cas9 mRNA to sgRNA from the traditional 1:2 to 1:10, which improves the efficiency of the homozygous mutation of biallelic gene. Here, a MSTN
Del73C mutation with FGF5 knockout sheep, in which the MSTN and FGF5 dual-gene biallelic homozygous mutations were produced via the deletion of 3-base pairs of AGC in the third exon of MSTN , resulting in cysteine-depleted at amino acid position 73, and the FGF5 double allele mutation led to inactivation of FGF5 gene. The MSTNDel73C mutation with FGF5 knockout sheep highlights a dominant 'double-muscle' phenotype, which can be stably inherited. Both F0 and F1 generation mutants highlight the excellent trait of high-yield meat with a smaller cross-sectional area and higher number of muscle fibers per unit area. Mechanistically, the MSTNDel73C mutation with FGF5 knockout mediated the activation of FOSL1 via the MEK-ERK-FOSL1 axis. The activated FOSL1 promotes skeletal muscle satellite cell proliferation and inhibits myogenic differentiation by inhibiting the expression of MyoD1, and resulting in smaller myotubes. In addition, activated ERK1/2 may inhibit the secondary fusion of myotubes by Ca2+ -dependent CaMKII activation pathway, leading to myoblasts fusion to form smaller myotubes., Competing Interests: MC, YZ, KY, XX, XZ, JZ, SW, ZL, YY, XG, SQ, GY, SW, HL, AW, GL, SD, HH, FL, DL, ZL No competing interests declared, (© 2023, Chen, Zhao, Yu et al.)- Published
- 2024
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