DNA FRAGMENTATION DURING THE PROGRAMMED CELL-DEATH IN THE CHICK LIMB BUDS

Programmed cell death plays a crucial role in limb morphogenesis of am niote. So far, there has been no biochemical evidence found to support the fact that embryonic cell death is apoptosis. In this report, we s how the oligo-nucleosomal ladder pattern of DNA obtained from interdig ital tissues of chick leg buds, indicating that programmed cell death has some features that are common to those involved in apoptosis. Furt hermore, cells exhibiting DNA fragmentation were detected by using a m ethod of in situ end labeling of DNA breaks. The distribution pattern of those cells corresponded well to those of programmed-dead cells sit uated within the interdigital mesenchyme of the leg bud. (C) 1994 Acad emic Press, Inc.