Differential Effects of Low- and High-Dose Gamma Irradiation on Hanwoo Muscle-Derived Satellite Cell Morphology and Gene Expression

Gamma irradiation is extensively employed for sterilization purposes in both the medical and food sectors. Recently, its use in cultured meat technology has emerged as an area of interest. Despite this, the specific impacts of gamma radiation on muscle stem cells that are crucial for cultured meat biomanufacture have not been well delineated, especially in livestock like Hanwoo. This study investigated the dose-dependent influence of targeted gamma irradiation on the morphology, viability, and gene expression profile of Hanwoo muscle-derived satellite cells utilizing a clinically certified Gamma Knife platform. Satellite cells were isolated from Hanwoo skeletal muscle by fluorescence-activated cell sorting (FACS) and exposed to gamma irradiation at Con(0), 2, 10, and 20 Gy. Following irradiation, cells were maintained under conditions promoting proliferation or differentiation. We evaluated cellular viability, morphological characteristics, and transcriptional levels of myogenic (<italic>MYF5</italic>, <italic>MYOD1</italic>, <italic>MYOG</italic>, <italic>MYH2</italic>) and cell cycle regulatory (<italic>TP21</italic>, <italic>TP53</italic>) genes. Exposure to high-dose gamma radiation (10 and 20 Gy) markedly reduced satellite cell proliferation, viability, and substrate attachment, also resulting in increased cell size and elevated expression of senescence-related markers <italic>TP21</italic> and <italic>TP53 </italic>(<italic>p</italic> < 0.05). A dose-dependent downregulation of myogenic gene expression was recorded, notably for <italic>MYF5</italic>, <italic>MYOD1,</italic> and <italic>MYOG</italic>. Importantly, low-dose irradiation (2 Gy) led to a transient elevation in <italic>MYH2</italic> expression while preserving cell viability and structural integrity, indicating possible hormetic responses (<italic>p</italic> < 0.05). Overall, gamma irradiation affects Hanwoo satellite cells in a dose-dependent manner, with higher doses promoting cellular aging and loss of myogenic potential, while lower doses may stimulate defense or differentiation-associated mechanisms. These results highlight the critical need for careful dose optimization when utilizing irradiation in cultured meat processes. Additional research is needed to delineate non-lethal radiation limits and confirm observations <italic>in vivo</italic>.