According to the public databases, there are currently approximately 1,900 locations in the human genome that produce microRNAs (miRNAs), the small and powerful non-coding molecules that regulate numerous cellular processes by reducing the abundance of their targets. New research published in the Proceedings of the National Academy of Sciences (PNAS) this week adds another roughly 3,400 such locations to that list. Many of the miRNA molecules that are produced from these newly discovered locations are tissue-specific and also human-specific. The finding has big implications for research into how miRNAs drive disease.
In the early 1990s, an international effort was launched by the U.S. Department of Energy and the National Institutes of Health to sequence the human genome. The project took 13 years, involved many scientists in several countries, and cost $2.7 billion (in FY 1991) dollars.