In vitro experiments have contributed to numerous fields of knowledge, including fish skeletal muscle. Despite improved strategies, in vitro assays still show discrepancies with in vivo systems, especially for non-model organisms. In this sense, we characterized the transcriptional profile of pacu ( Piaractus mesopotamicus ) muscle cells in vitro and in vivo . Processes related to proliferation, glycolytic metabolism, and extracellular matrix were enriched in vitro , while energy production, muscle contraction, and amino acid processing were enriched in vivo . Through qPCR, the genes fn1a (fibronectin 1a) , hk1 (hexokinase 1), and ctnnb1 (catenin beta 1) , respectively related to extracellular matrix, glycolytic metabolism, and cell proliferation and differentiation, were highly expressed in vitro . The genes ckma (creatine kinase, muscle a) , acat1 (acetyl-CoA acetyltransferase 1) , mdh2 (malate dehydrogenase 2), and pkmb (pyruvate kinase M1/2b) , respectively associated with ATP production, fatty acid oxidation, oxidative and glycolytic metabolism, and the genes musk (muscle, skeletal, receptor tyrosine kinase) , chrna1 (cholinergic receptor, nicotinic, alpha 1) and clu (clusterin) , involved in cell signaling, were highly expressed in vivo . Overall, our results indicate that the main limitation of in vitro muscle cell model is the maintenance of an embryonic-like molecular state, whereas in vivo muscle displays a mature transcriptional profile, providing a molecular basis to guide future strategies for improving fish muscle cell culture systems and supporting advances in sustainable aquaculture and in vitro meat production. • Fish in vitro muscle cells limit energy generation pathways when isolated • Cell communication is a key point for fish in vitro muscle cell proliferation • Extracellular matrix is essential for the in vitro maintenance of fish muscle cells • Findings highlight the needs, limitations, and biology of fish muscle cell culture • Results can be applied in the future development of cultured fish meat.
Zanella et al. (Tue,) studied this question.