Cell competition is a conserved phenomenon spanning from arthropods to humans. It involves the elimination of viable yet suboptimal "loser" cells when juxtaposed with their fitter "winner" counterparts. This process has received increased attention for its implications in cancer initiation and progression, neurodegeneration, and ageing.

This study investigates the presence of the loser fitness fingerprint Flower LoseB (Fwe LB) and the fitness checkpoint Azot in the optic lobes over a period of 28 days. Notably, the absence of Azot is conventionally linked to the accumulation of loser cells over time. However, our investigation reveals that this accumulation is not perpetual and, intriguingly, Azot is not required for loser cell elimination in this context because loser cells are still eliminated by apoptosis in its absence. Furthermore, we wanted to clarify the percentage of loser cells that are eliminated, and the percentage of dying cells identified as loser during cell competition. We estimate that fewer than 50% of Fwe LB-expressing cells also express Azot and undergo apoptosis. Remarkably, our calculations also demonstrate that over 50% of cells undergoing apoptosis at any given time point are positive for the loser markers Fwe LB and Azot, stressing the relevant role of cell competition in promoting the elimination of suboptimal cells.

This comprehensive analysis of fitness marker dynamics over a 28-day timeframe sheds new light on the intricate mechanisms governing Flower-dependent cell competition.    

Cell Competition, Flower LoseB, Azot, Apoptosis