Micro RNAs

Micro RNAs encode 21-25 nt RNAs, which are generated from a longer precursor. First discovered as the products of the C. elegans heterochronic genes lin-4 and let-7, micro RNAs have very recently been found to be widespread in biology, present in Drosophila, mammals, plants and other organisms. The C. elegans genome encodes more than 100 micro RNAs. Other than lin-4 and let-7, which act to control developmental timing by inhibiting the translation of the target mRNAs to which they bind, no micro RNA in any species has been assigned any biological function. To explore the functions of micro RNAs, we are collaborating with the laboratories of David Bartel (Whitehead Institute, MIT) and Victor Ambros (Dartmouth) to generate deletions in most and maybe all C. elegans micro RNA genes. In addition, we are examining micro RNAs from mammals, with a particular focus on those that function in the nervous system.