Total mRNA and primary human myoblasts’ in vitro cell cycle progression distinguishes between clones

Satellite cells are generally quiescent in vivo. Once activated, progression through the cell cycle begins. Immortalised myoblasts from a single cell line are fairly homogenous in culture, but primary human myoblasts (PHMs) demonstrate heterogeneity. This phenomenon is poorly understood however may impact on PHM expansion. This study aimed to evaluate cell cycle transition from growth to synthesis phases of the cell cycle (G1 to S phase) and total mRNA relevant to this transition in PHM clones derived from 2 donor biopsies. Proportions of cells transitioning from G1 to S phase were evaluated at 2-hourly intervals for 24 h (n = 3 for each) and total mRNA quantified. Both PHM clones revealed an exponential transition from G1 to S phase over time, with a significantly slower rate for PHMs from S9.1 compared to S6.3, which had a higher proportion of PHMs in S phase for most time-points (p