ABSTRACT
Mammalian cells of solid tissue origin generally require some degree of intercellular communication with neighboring cells to maintain their viability and proliferative capacity. This requirement presents itself as a density dependent promotion of growth at sparse densities. Cellular generation times exhibit a number of interesting features that have puzzled investigators for several decades. Cell behavior and function are governed by a complex hierarchy of cooperative interactions and intercellular communications. Despite random seeding, most mammalian cells quickly cluster into discrete colonies. This colonization increases the local population density of most cells to a value that is very much higher than the global average for the culture as a whole. This density dependent growth promotion generally reaches its maximum intensity at comparatively sparse densities that are often below the normal working range for routine cell culture. Scientist suggests, that the peculiarities of mammalian cell generation times are caused by differences between the microenvironments of individual cells.
