For decades, scientists have neglected RNA molecules, assuming that they were little more than messengers carrying genetic instructions from DNA to manufacture the proteins that rule our lives.
Now, thanks to a spate of discoveries in recent years, it appears that humble RNA assumes a surprising variety of other forms that do much more than deliver messages. Snippets of RNA actually become enforcers in the cell, interfering with the instructions from certain genes or shutting them down altogether.
The discoveries have electrified biologists, shaking up long-held theories of genetics. Science magazine declared the rapidly expanding understanding of what are called "small RNAs" the research breakthrough of last year.
Much remains to be understood about how small RNAs work, but research suggests that they play a role in the development of plants and animals, as well as in fending off illnesses. Several biotechnology companies have begun to work on translating the findings into new medicines.
As their names suggest, RNA and DNA are related molecules, strings of chemical building blocks called nucleotides that make up the genetic code. The instructions for making proteins which "build" and maintain everything from our muscles to the hemoglobin in our blood are copied from genes in the double-stranded DNA onto a single-stranded RNA, which then conveys the blueprint to the cell's protein-making factories.
The excitement is focusing on short stretches of RNA just 21 to 28 base pairs in length, which had been largely overlooked by researchers.
In 1998, Andrew Z. Fire of the Carnegie Institution of Washington, a private nonprofit lab in Baltimore, and others injected worms with "double-stranded" RNA, so named because the single-stranded molecule bends back on itself. They saw that the new molecules silenced the genes responsible for producing that RNA.
Researchers have since probed deeper into RNA interference, identifying a "dicer" enzyme that chops the double-stranded RNA into bits, which then silence genes by latching onto messenger RNA.
Studying yeast and a microbe found in freshwater lakes and streams, researchers found last year that small RNAs can permanently shut down or delete whole sections of DNA. The observations suggest that small RNAs play a previously unrecognized role in regulating cell division.
Now, thanks to a spate of discoveries in recent years, it appears that humble RNA assumes a surprising variety of other forms that do much more than deliver messages. Snippets of RNA actually become enforcers in the cell, interfering with the instructions from certain genes or shutting them down altogether.
The discoveries have electrified biologists, shaking up long-held theories of genetics. Science magazine declared the rapidly expanding understanding of what are called "small RNAs" the research breakthrough of last year.
Much remains to be understood about how small RNAs work, but research suggests that they play a role in the development of plants and animals, as well as in fending off illnesses. Several biotechnology companies have begun to work on translating the findings into new medicines.
As their names suggest, RNA and DNA are related molecules, strings of chemical building blocks called nucleotides that make up the genetic code. The instructions for making proteins which "build" and maintain everything from our muscles to the hemoglobin in our blood are copied from genes in the double-stranded DNA onto a single-stranded RNA, which then conveys the blueprint to the cell's protein-making factories.
The excitement is focusing on short stretches of RNA just 21 to 28 base pairs in length, which had been largely overlooked by researchers.
In 1998, Andrew Z. Fire of the Carnegie Institution of Washington, a private nonprofit lab in Baltimore, and others injected worms with "double-stranded" RNA, so named because the single-stranded molecule bends back on itself. They saw that the new molecules silenced the genes responsible for producing that RNA.
Researchers have since probed deeper into RNA interference, identifying a "dicer" enzyme that chops the double-stranded RNA into bits, which then silence genes by latching onto messenger RNA.
Studying yeast and a microbe found in freshwater lakes and streams, researchers found last year that small RNAs can permanently shut down or delete whole sections of DNA. The observations suggest that small RNAs play a previously unrecognized role in regulating cell division.