PSX-A-13 - Late-Breaking: Establishing an in vitro model for studies of myogenesis in broiler chicks

The objective of this work was to establish protocols for isolating, maintaining, and differentiating SCs from broiler embryos and young chicks so that this model can be used to identify factors that affect myogenic development. Efficient production of lean and healthy muscle is the ultimate goal of the livestock industry. Skeletal muscle develops from a population of multipotent stem cells, also known as satellite cells (SCs), that have the potential to differentiate into both muscle cells and adipocytes. During embryonic and early postnatal development, nutritional and hormonal cues interact to influence the cell fate of this cell population, which ultimately affects body composition and muscle quality. In broilers, the factors that influence the early development of SCs are particularly important due to the high incidence of breast muscle myopathies in commercial flocks. Methods to isolate SCs from multiple species, including chicken, have been described in the literature. However, SCs in very young animals have different growth and differentiation properties, and the fiber properties of the muscle, which influence the digestion strategy, differ from those of mature birds. Protocols were developed using p. major muscle of 7 day-old-broiler chicks. Satellite cells were isolated from intact muscle by two-step enzymatic digestion and purified from other cell types based on differential adherence to tissue culture plastic. Enrichment for SCs in each procedure was evaluated based on the ability to undergo myogenic differentiation and form myotubes in vitro. Immunofluorescent staining for Pax7, a marker of SCs, and flow cytometry for CD56, a surface marker for SCs, were used to confirm a high purity population of SCs. In conclusion, we have established a model that will be valuable for assessing the impact of nutrients, metabolites, and other physiological cues on early life muscle growth and development in broilers.