Cell death in limb bud of a webbed foot

A light microscope image of the developing foot of a mouse embryo showing areas of dying cells between the digits. The limb starts off as a paddle shape, but areas of programmed cell death (apoptosis) appear between the regions where the digits will form. The dead cells are removed by scavenging cells called macrophages (stained green), resulting in the formation of toes. Biomedical Image Awards 1998.