About 10 billion of our cells die on a normal day just to counter the numbers of new cells that arise. This programmed cell death, or apoptosis, is one of the hottest areas of modern biology. Apoptosis is an essential part of life for any multicellular organism and is conserved from worm to mammal. During development, apoptosis helps to sculpture the body, shape the organs, and carve out fingers and toes. Both the nervous system and the immune system arise through overproduction of cells followed by the death of those that fail to develop the necessary functions.
Apoptosis purges the body of pathogen-invaded cells, but also eliminates unwanted immune cells.
Such massacre has to be tightly regulated as too little or too much cell death may lead to, amongst other things, developmental defects, autoimmune diseases, neurodegeneration or cancer. Not surprisingly, then, the hunt is on to understand which cells die when, why and how precisely, and to find drugs that interfere with specific steps along the pathway. A new method of preparing 'SNP' maps to guide researchers through variations in the human genome is reported, alongside one such chart for human chromosome 22. In a second paper, scientists describe a new technique used to generate SNP maps. These are the first publications on progress by the SNP Consortium - an international collaboration aiming to discover and release 300,000 human SNPs.