CAMBRIDGE, Mass., Jan. 15 (UPI) -- U.S. researchers say they have discovered a new class of ribonucleic acid, or RNA.
The team, led by Professor David Bartel of the Massachusetts Institute of Technology identified more than 5,000 of the new molecules, termed 21U-RNAs -- named after their distinctive features. Every molecule contains 21 nucleotides, each beginning with the chemical uridine, represented by the letter U -- the only RNA nucleotide not also found on DNA. In addition, each of the 21U-RNA molecules comes from one of two chromosomal regions.
"We can predict where additional 21U-RNA genes might reside," said Bartel, who is also a member of the Whitehead Institute for Biomedical Research and a Howard Hughes Medical Institute investigator. "Combining these predictions with the 5,000 (21U-RNAs) that we experimentally identified, we suspect there are more than 12,000 different 21U-RNA genes in the genome.
"There are so many 21U-RNA genes spread out over ... a wide swath of the genome, but they all share common requirements for expression and common structural features," added Bartel lab student J. Graham Ruby, lead author of the paper.
The findings are reported in the current issue of the journal Cell.
