Tnni3k influences cardiomyocyte S-phase activity and proliferation

Cardiomyocyte proliferation is a difficult phenomenon to capture and prove. Here we employ a retrospective analysis of single cell ventricular suspensions to definitively identify cardiomyocytes that have completed cell division. Through this analysis we determined that the capacity of cardiomyocytes to re-enter the cell cycle and complete cell division after injury are separate and variable traits. Further, we provide evidence that Tnni3k definitively influences both early and final stages of the cell cycle. [Display omitted] •CM ploidy in the naïve adult myocardium and cell cycle activity in response to injury are highly variable traits.•Some of the genetic drivers that regulate CM ploidy also in turn influence cell cycle activation and completion after injury.•Tnni3k influences both S-phase activity and completion of the cell cycle.