2017/04/26

‘Junk DNA’ no more? Most long non-coding RNA likely functional, study finds

The number of functional long non-coding RNAs exceeds the number of protein coding genes present in human cells

https://epigeneticsliteracyproject.org/junk-dna-no-long-non-coding-rna-functional-study-finds/

Excerpt: "Researchers have now catalogued nearly 28,000 long noncoding RNAs (lncRNAs) present in human cells, and found that roughly 20,000 are likely functional. The study, published yesterday (March 1, 2017) in Nature, also suggests that about 2,000 lncRNAs are associated with diseases."

http://fantom.gsc.riken.jp/cat/?cultureKey=&q=cat


Excerpt: "Long non-coding RNAs (lncRNAs) are largely heterogeneous and functionally uncharacterized. Here, using FANTOM5 cap analysis of gene expression (CAGE) data, we integrate multiple transcript collections to generate a comprehensive atlas of 27,919 human lncRNA genes with high-confidence 5′ ends and expression profiles across 1,829 samples from the major human primary cell types and tissues. Genomic and epigenomic classifications of these lncRNAs reveals that most intergenic lncRNAs originate from enhancers rather than from promoters."

http://www.whatisepigenetics.com/non-coding-rna/

Excerpt: "Many lncRNAs can complex with chromatin-modifying proteins and recruit their catalytic activity to specific sites in the genome, thereby modifying chromatin states and influencing gene expression. The majority of non-coding RNA transcripts belong to the group lncRNAs. Long ncRNAs function in chromatin remodeling, transcriptional regulation, post-transcriptional regulation, and as precursors for siRNAs."

My comment: Long non-coding RNA molecules have several epigenetic jobs in regulating gene expression, chromatin structure and cellular identity. Most lncRNAs originate from enhancers, that are typically methylated regions of certain genes. Both long and small ncRNAs can also impact on epigenetic programs. Epigenetic patterns can be transmitted from one cell to the daughter cell, but, importantly, also through generations.

Long non-coding RNAs don't support the theory of evolution. For example, only 880 lncRNAs were similar between a mouse and a human cell. And a comparison of a human-chimp lncRNAs doesn't give any better results. This is again bad news for proponents of the 
theory of evolution.

https://genomebiology.biomedcentral.com/articles/10.1186/s13059-016-0880-9

Sshh, Darwin didn't know about this.