Addressing hurdles in cultured meat by exploring reduced myogenesis after bovine myoblast expansion

When considering non-genetically modified primary bovine cells for large-scale cultured meat production, one must account for their biological limitations, such as proliferation and differentiation capacity. This study tests these limitations in primary cells from fetal and adult bovine donors. Bovine myoblasts are expanded past 30 doublings and characterized for CD56 expression, senescence, and myogenic differentiation capacity. Contrary to the Hayflick limit, several cell lines from adult cows surpass 60 population doublings, all with normal karyotypes. One line maintains high CD56 expression for the first 25 doublings. However, differentiation capacity declines, with fetal-derived cells showing high fusion indexes early on, but minimal fusion in both adult- and fetal-derived cells past 25 doublings. Differential transcriptomic and proteomic analyses of adult myoblasts with higher versus lower fusion indices identify many significantly affected genes and pathways. Genes related to myogenesis, DNA repair, and calcium signaling, among others, are downregulated in low fusing cells. This research shows the potential to expand unmodified primary bovine myoblasts for industrial cultured meat production, but further research is needed to address the lack of differentiation in expanded cells to replicate the fibrous texture and protein composition of meat.