Can cell mortality determine division of labor in tissue organization?

Abstract

Tissue organization comes from the emergence of cell cooperation where cell homeostasis and function are per- formed as a trade-off of two excluding proliferative and differentiated cellular states. By introducing function in a population dynamics approach, I study the role of division of labor in tissue optimality when cell turn-over and limi- tation of space and resources are imposed as natural restrictions of a living tissue. The results indicate that although cell turn-over imposes a inevitable reduction in function abilities, the penalty is smaller when division of labor is at work, specially when a rapid cell-turnover and high cell density is a requirement for the tissue, as occurred in epithelia hierarchical tissues. Analytic results are in agreement with the experimental data available in literature. The study provides an explanation about why homogeneous tissues for which proliferative and functional tasks are performed by a same cell type are unlikely to be observed under high cell-renewal requirements.