摘要
In 1993 when Ambros and co-workers [1] discovered that a mysterious Caenorhabditis elegans gene, lin-4, does not encode a protein, but acts in the form of a small RNA and represses the expression of its target gene, lin-14, through base-pairing with its 3＇ untranslated region （3tUTR）, nobody would imagine that 20 years later, this category of small RNAs - now widely known as microR- NAs （or miRNAs）, has ～2000 known members in the human genome （and counting）, and that miRNA-mediated gene regulation is deeply involved in virtually all important biological processes in animals and plants.
In 1993 when Ambros and co-workers [1] discovered that a mysterious Caenorhabditis elegans gene, lin-4, does not encode a protein, but acts in the form of a small RNA and represses the expression of its target gene, lin-14, through base-pairing with its 3＇ untranslated region （3tUTR）, nobody would imagine that 20 years later, this category of small RNAs - now widely known as microR- NAs （or miRNAs）, has ～2000 known members in the human genome （and counting）, and that miRNA-mediated gene regulation is deeply involved in virtually all important biological processes in animals and plants.
