Red blood cells have a killer touch

Red blood cells need their space, suggest results from Merav Socolovsky (University of Massachusetts Medical School), Andre Levchenko (Johns Hopkins University), and colleagues. Fetal developing red blood cells, they show, might just kill some of the brethren they are close enough to touch.

During early embryogenesis, red blood cells need to be produced at a high rate to keep the embryo well oxygenated. Their precursors therefore start out growing ten times faster than the fetus as a whole. This fecundity must be shut down at the right time to prevent overgrowth. To determine how growth is limited, the group measured cell numbers at each stage of RBC development and constructed a mathematical model to fit the numerical data. The model predicted the existence of negative autoregulation as a...