Two groups of researchers have unearthed a whole new class of small RNA molecules manufactured by the mammalian genome. They might have a role in the production of sperm, and expand the growing range of functions attributed to non-protein-coding RNA. The two linked papers are published online by Nature.
Researchers are already familiar with microRNAs, 21-23 nucleotide fragments that can silence genes and act by binding to a group of Argonaute proteins. It was also known that a subgroup of Argonaute proteins, known as the Piwi family, is important in the production of germ cells.
The two teams, led by Thomas Tuschl and Gregory Hannon, show that certain members of the Piwi family in mice actually bind to a previously unknown class of slightly longer RNAs, somewhere between 26?31 nucleotides in length and abundant in developing sperm. These Piwi-interacting RNAs (piRNAs) are common in the mouse genome and lie in clusters, suggesting that they are actually cut out of longer RNA transcripts. Similar piRNAs are generated from the human genome.
Thomas Tuschl (Howard Hughes Medical Instiute, The Rockefeller University, New York, NY, USA)
Gregory Hannon (Cold Spring Harbor Laboratory, NY, USA)
Abstracts available online:
(C) Nature press release.
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