RESUMEN
A birth-death model was developed for the proliferation of mast cells. According to the model, each secondary mast cell colony starts with one proliferative cell. At each generation each cell chooses among three possibilities: 1) division into two proliferative cells; 2) division into two non-proliferative cells; or 3) disappearance. At each step, a non-proliferative cell either does nothing or disappears. A computer simulation of this model could be fitted reasonably well to our data for the size distributions of secondary mast cell colonies recorded after different culture periods. Our model predicts that proliferative cells comprise a larger fraction of the colony in large secondary colonies than in small ones. This prediction was successfully tested by examination of tertiary colony formation. This is a general model for cell proliferation that may be applicable to other types of cells.