SAP30 gene editing in muscle cells. CRISPR/CAS9 INDUCED MUTATIONS IN THE SAP30 GENE CAUSE MUSCLE CELL HYPERTROPHY

Muscle attributes as growth rate and size are important because it impacts economically traits in animal production. Muscle development is also important from a basic science perspective to understand the underlying biology of cell determination and differentiation. Moreover, understanding the genetic machinery involved in muscle development should allow advances in animal breeding programs. Master regulatory genes such as myogenic factors have been identified and characterized, but genome-wide association studies indicate that many other candidate genes could be modulating muscle development. In a previous QTL study in chickens, we identified SAP30 as a probable candidate for muscle development in a Brazilian broiler line. Here, we used CRISPR/Cas9 to edit SAP30 and investigate the effect of the gene mutations in C2C12 cell line. Morphometric analysis from three different clones revealed the SAP30 involvement in muscle hypertrophy, but the biological processes remained unknown. RNA sequencing analysis was used to identify genes and pathways linking SAP30 with muscle hypertrophy. Functional enrichment analyses indicate that SAP30 regulates the expression of additional genes involved in muscle development. In addition, genes that participate in muscle growth and regeneration pathways, such as NOTCH and WNT, had their expression modulated by mutations in the SAP30 gene. These results indicate new details about the SAP30 participation in muscle development.