[
Nature,
2001]
The degredation of DNA is one of the hallmarks of programmed cell death (apoptosis). When forced to commit suicide, apoptotic cells - like good secret agents - grimly destroy their "instruction book," chewing up their genomic DNA into tiny morsels. Until now, only two DNA-destroying enzymes (nucleases) with a clear role in cell death were known, one in mammals and one in the nematode worm Caenorhabditis elegans. But, on pages 90-99 of this issue, Li and colleagues and Parrish and co-workers show that another nuclease, endonuclease G (endoG), also contributes to the carnage, and might even influence the likelihood that a cell will live or die.
[
Dev Cell,
2013]
Genomes are constantly challenged by invaders, so determining what belongs is crucial. Small RNAs silence alien DNA, but Conine etal. (2013), Seth etal. (2013), and Wedeles etal. (2013) now report in Cell and Developmental Cell that these tiny transcripts can also license trusted DNA for expression.