Abundance of Long NcRNAs
A recent study found only one-fifth of transcription across the human genome is associated with protein-coding genes (Kapranov 2007), indicating at least four-times more long non-coding than coding RNA sequences. However, it is large-scale complementary DNA (cDNA) sequencing projects such as FANTOM (Functional Annotation of Mammalian cDNA) that reveal the complexity of this transcription (Carninci 2005). The FANTOM3 project identified ~35,000 non-coding transcripts from ~10,000 distinct loci that bear many signatures of mRNAs, including 5’capping, splicing, and poly-adenylation, but have little or no open reading frame (ORF) (Carninci 2005). While the abundance of long ncRNAs was unanticipated, this number, nevertheless, represents a conservative lower estimate, since it omitted many singleton transcripts and non-polyadenylated transcripts (tiling array data shows more than 40% of transcripts are non-polyadenylated) (Cheng 2005). However, unambiguously identifying ncRNAs within these cDNA libraries is challenging, since it can be difficult to distinguish protein-coding transcripts from non-coding transcripts.
Read more about this topic: Long Non-coding RNA
Famous quotes containing the words abundance of, abundance and/or long:
“Slavery is founded in the selfishness of man’s nature—opposition to it, is [in?] his love of justice.... Repeal the Missouri compromise—repeal all compromises—repeal the declaration of independence—repeal all past history, you still can not repeal human nature. It still will be the abundance of man’s heart, that slavery extension is wrong; and out of the abundance of his heart, his mouth will continue to speak.”
—Abraham Lincoln (1809–1865)
“What you desire when young, you have in abundance when old.”
—Johann Wolfgang Von Goethe (1749–1832)
“So long as a man rides his Hobby-Horse peaceably and quietly along the King’s highway, and neither compels you or me to get up behind him—pray, Sir, what have either you or I to do with it?”
—Laurence Sterne (1713–1768)