CRISPR/Cas9‐mediated MSTN disruption accelerates the growth of Chinese Bama pigs

Abstract

CRISPR/Cas9-mediated genome editing technology is a simple and highly efficient and specific genome modification approach with wide applications in the animal industry. CRISPR/Cas9-mediated genome editing combined with somatic cell nuclear transfer rapidly constructs gene-edited somatic cell-cloned pigs for the genetic improvement of traits or simulation of human diseases. Chinese Bama pigs are an excellent indigenous minipig breed from Bama County of China. Research on genome editing of Chinese Bama pigs is of great significance in protecting its genetic resource, improving genetic traits and in creating disease models. This study aimed to address the disadvantages of slow growth and low percentage of lean meat in Chinese Bama pigs and to knock out the myostatin gene (MSTN) by genome editing to promote growth and increase lean meat production. We first used CRISPR/Cas9-mediated genome editing to conduct biallelic knockout of the MSTN, followed by somatic cell nuclear transfer to successfully generate MSTN biallelic knockout Chinese Bama pigs, which was confirmed to have significantly faster growth rate and showed myofibre hyperplasia when they reached sexual maturity. This study lays the foundation for the rapid improvement of production traits of Chinese Bama pigs and the generation of gene-edited disease models in this breed.

Application of the modified cytosine base-editing in the cultured cells of bama minipig

“…Subsequently, Rao et al used TALEN technology to successfully obtain MSTN gene-edited pigs and showed that the muscle bers of these pigs became thinner and more numerous, exhibiting the double-muscled phenotype in the hips (Rao et al, 2016). In 2020, Li et al and our group obtained MSTN-knockout miniature pigs and Bama minipigs, respectively (Li et al, 2020;Zhu et al, 2020b). Both breeds showed an increase in the number of muscle bers and a decrease in muscle ber size, indicating that the geneediting mediated MSTN-knockout signi cantly improved the meat production traits of pigs and increased their economic value.…”

“…Although the application effect of the modi ed CBE tool on pigs might not be very high, in the practice of single-base editing of porcine cells, different editing targets could be compared, and the targets with higher relative activity could be selected for application. For example, in this study the four candidate targets were analyzed and compared to select the most active target and more e ciently prepare CBE-mediated single-base editing cells of Bama minipigs, thereby laying the foundation for the next step of producing single-base edited pigs through somatic cell cloning.In previous studies, MSTN-knockout was mainly achieved by CRISPR/Cas9-mediated random base insertion/deletion mutations leading to frameshift mutations(Li et al, 2020;Zhu et al, 2020b). Because the mutations are random and unpredictable, and CRISPR/Cas9 is prone to cause a series of adverse genomic consequences, there are many concerns about biosafety.…”

Alterations of the Muscular Fatty Acid Composition and Serum Metabolome in Bama Xiang Mini-Pigs Exposed to Dietary Beta-Hydroxy Beta-Methyl Butyrate

“…Bama Xiang mini-pigs, an indigenous minipig breed from Bama Country of China, grow slowly and are lighter and fatter than the modern breeds such as Large White at slaughter, which makes them an ideal experimental animal model for biomedical research [ 22 , 23 ]. Notably, too-high fat content in skeletal muscle will greatly decrease the purchasing decisions of customers, thus decreasing the economic value of Bama Xiang mini-pigs [ 8 ].…”

Genes Related to Fat Metabolism in Pigs and Intramuscular Fat Content of Pork: A Focus on Nutrigenetics and Nutrigenomics

“…This gap necessitates further research to understand how it influences pork fat metabolism, IMF deposition and other meat quality traits. A study [ 101 ] shows that MSTN knockout using CRISPR/Cas9-mediated genome editing with subsequent somatic cell nuclear transfer offers a promising possibility for genetic improvement of economically important traits in pigs. Ren et al [ 79 ] demonstrated the active potential of MSTN in inhibiting the growth of muscles (double muscling) and acts via myogenic transcription factor 2C ( MEF2C ) which binds to the miR-222 promoter and suppress the translation of SCD5 to affect fat deposition [ 79 ].…”