Principal Investigator Harvey Lodish
MicroRNAs (miRNAs) are small endogenous ~22-nt non-coding RNAs that base pair to sites within target mRNAs, triggering either a block in translation or mRNA degradation or both. The expression of miRNAs is often tissue-specific or developmental-specific. As shown by the Bartel laboratory and others, humans have several hundred genes that encode miRNAs, an abundance corresponding to almost three percent of protein-coding genes; computational and experimental analyses suggest that miRNAs may regulate expression of ~30% of human and mouse genes. Based on the evolutionary conservation of many miRNAs among different animal lineages, it is reasonable to suspect that some mammalian miRNAs have important conserved functions in cellular development and function. Indeed, the post-transcriptional programs controlled by specific miRNAs affect diverse biological processes, including development, cell differentiation, apoptosis, immune responses, metabolism and many diseases including various cancers, cardiovascular disease, viral infection and neurodegenerative diseases. Long non-coding RNAs (lncRNAs), transcripts longer than 200nt, constitute a significant fraction of the mammalian transcriptome. While many lincRNAs are differentially expressed under both normal and pathological conditions, the biological functions of most of these transcripts still remain uncharacterized.