Standing guard: Perinuclear localization of an RNA-dependent RNA polymerase

摘要

Sexual reproduction has both potential benefits and potential hazards for the fitness of a genome. The genetic shuffling that accompanies meiosis is recognized as a way of testing genetic variation against environmental changes to select for evolutionary fitness. However, sexual reproduction can also assist the spread of infectious genetic parasites by intermingling two genomes. Meiosis-specific defense mechanisms have arisen to combat this hazard, and this type of defense is strikingly evident in the filamentous fungus Neurospora crassa. A recent study by Shiu et al. (1) in this issue of PNAS sheds new light on a meiotic process that targets transcripts from unpaired regions of chromosomes for destruction during meiosis.