Long non-coding RNA

(Long ncRNA, lncRNA) long non-coding RNA is a long non-protein-coding transcripts than 200 nucleotides. The arbitrary limit, micro RNA is (miRNA), short interfering RNA (the siRNA), PIWI interacting RNA (piRNA is), from this small regulatory RNA such as RNA) other short small nucleolar RNA and (snoRNAs) somewhat I will distinguish between the long ncRNA. In a recent study, indicating that long at least four times than not encoded encrypted RNA sequence, and is associated with a gene encoding the protein, but a fifth of the transfer in the human genome, the only found. However, it is (functional annotation of mammalian DNA) (DNA) sequencing project FANTOM major and complementary DNA to reveal the complexity of the transfer. 5 ‘cap, splicing, and FANTOM3 project will bear the signature of the mRNA of many, including the polyadenylation, and 35,000 non-coding transcription loci – different to 10,000 you have open reading frame (ORF) with little or no I identified the product. (Data of tiling array will be displayed more than 40% of the transcript is not polyadenylated), so has been omitted non-polyadenylated transcripts and transcripts of many false, it is expected rich of long ncRNA In spite of it was outside, however, this figure is a low estimate conservative. Be distinguished transcripts encoding proteins from non-coding transcripts but difficult and ncRNA a clear identification of the cDNA libraries in these, it is a challenge.

This landscape mammalian genome has been described as a “focal point” of multiple transcription that are separated by a long stretch of the intergenic region. As played in intergenic regions and antisense RNA long, it is transcribed as a network entangled composite antisense transcript sense and largely overlap, which comprises a gene encoding a protein often. Give rise to a complex hierarchical structure of overlapping isoforms often, lesions transcription in the genomic sequence of these are shared by the number of anti-sense direction and sense of non-code entry and different encoding. For example, were identified as non-coding variants true cDNA encoding a protein of cDNA described later by 3012 8961 annotated coding sequence described above was truncated at FANTOM2. In spite of the conservation and richness of these arrangements intertwined, they suggest that you have a block evaluated in the complex simple and biological significance of these stylish. Its genomic organization and human annotation lncRNA, benchmark consortium GENCODE a wide range of tissue expression profiles and cell site of change. Their analysis, it indicates that shows a bias human lncRNAs, the two exon transcript.

RNA many small, such as snoRNAs or micro RNA shows a strong conservation in different species. In contrast, strong conservation ncRNA lack of generally longer, cited as evidence of non-functionality often from this. However, many, suggesting that may be subject to selective pressure different, as long as XIST and air are not well conserved, ncRNA’s explained, well ncRNA of such. In contrast to the mRNA’s need to hold the codon usage, to prevent the frame mutations ORF one long, selected regions having a short long antisense RNA, which is limited by the sequence specific interaction or structure It can be maintained for. Therefore, the choice to confirm the action on the basis of a small area of ​​non-coding transcripts long only. However, despite the long antisense RNA low protection generally, antisense RNA very long it should be noted that it comprises a storage element still highly it. For example, 19 percent of the functions that are highly conserved can be seen in 32% and another phastCons intron known in the region without annotation. In addition, indicators of purification, replacement, small insertion / deletion rate, a representative set of non-coding RNA long human, pretty still choose to maintain the integrity of the transcription level of splicing sequence and promoter, I show a decrease.

The poor preservation of the ncRNA, recently, may be the result of rapid adaptive selection. For example, antisense RNA can be demonstrated by the presence of ncRNA strains of a very specific, such as air and XIST, the more flexible the pressure in the evolution of protein-coding gene. In fact, many of the human genome is the subject of evolutionary change in recent chimpanzee genomes, conserved region thereof is transferred, is primarily found in the non-coding region. This has made rapid evolutionary change in humans, in particular, non-coding, which is expressed in Cajal-Retzius cells in human cortex, including HAR1F. There is a limit to the plastic structure more features, may lead to an array of these, observed functional verification RNA that many developing quickly, can expect a lot of innovation evolution of such a sequence. This was confirmed by the presence of thousands sequence of the mammalian genome showing the poor preservation of the sequence level, there is evidence for the secondary structure of RNA saved.