Geneticists have compiled an atlas of long non-coding RNAs

Denis Strigun, Naked Science

Non-coding RNAs are molecules that, unlike, for example, matrix RNAs (mRNAs), do not participate in protein synthesis. It is assumed that these molecules may play a leading role in chromatin remodeling and DNA methylation, but their exact functions are not clear. One of the variants of non-coding RNAs is long non-coding RNAs (from 400 to tens of thousands of nucleotides), the number of which in the human genome is approximately estimated at 30 thousand molecules.

The study of long non-coding RNAs is hampered by their low expression and a wide range of possible biogenesis. At the same time, the locus of some long non-coding RNAs are not transcripts (molecules formed as a result of gene expression), but the transcription process itself. Therefore, the evaluation of long non–coding RNAs by selective restrictions and genetic variations seems most likely, and their description by the 5’ ends of transcripts.

Meanwhile, the sequencing method, which is usually used to study non-coding RNAs, often does not allow to determine the 5’ ends of their transcripts with high accuracy. In the new work, the participants of the FANTOM project, led by the Japanese Center for Natural Sciences and Technology RIKEN, used cap analysis of gene expression (CAGE) for this purpose. The authors constructed expression profiles based on 1829 samples of human cells and tissues and compared the results with known data.

As a result, scientists "mapped" 27919 long non-coding RNAs, and comparison with the available data allowed us to identify 19175 of those that probably perform a certain function. Thus, the number of functional long non-coding RNAs in the human genome can be comparable to or exceed the number of genes encoding proteins (about 20 thousand).

Drawing from the press release of RIKEN Improved gene expression atlas shows
that many human long non-coding RNAs may actually be functional

The conclusions of the work also cast doubt on the hypothesis that long non-coding RNAs are not independent molecules, but the "noise" of the transcription apparatus of eukaryotic cells, the authors believe.

Details of the study are published in the journal Nature (Hon et al., An atlas of human long non-coding RNAs with accurate 5' ends). You can get acquainted with the new atlas of long non-coding RNAs on the project's website.

Portal "Eternal youth" http://vechnayamolodost.ru  02.03.2017