Science Daily — Tiny molecules called microRNAs, only 19 to 21 nucleotides in length, are able to effectively silence sometimes large sets of genes. They do this by specifically binding to and neutralizing another form of RNA called messenger RNA, responsible for conveying the information from genes to the cellular machinery that uses that information to create proteins, the building blocks of the body. Several hundred species of microRNAs have been identified to date, and increasingly they are being seen as vitally important players in regulating the genome.
