More Cool Genetics

So a month or so ago a paramutation phenomenon involving non-mendelian inheritance was discovered in mice. Evidence in that paper suggested that genetic information was passed on through a germ cell pool of RNA in addition to DNA. Interestingly, another Nature paper now shows that the more well-known phenomenon of paramutation in Maize relies on an RNA-dependent RNA polymerase known to be involved in the production of siRNAs. The idea is that this enzyme makes RNA molecules that affect heritable chromatin states that in turn affect transcriptional activity.