Table 2.

Long non-coding RNA characteristics

GENCODE established lncRNA characteristics [31]
lncRNAs are independent transcriptional units that lack protein-coding potential. They are not unrecognized extensions of neighboring protein-coding genes
lncRNA genes can have an unusual exonic structure, but their processing, splicing signals, exon/intron length, and poly-adenylation are similar to those of protein-coding genes
lncRNA genes, when expressed, have the typical histone modifications associated with active transcription but show more tissue-specific and generally lower expression than protein-coding genes
Human lncRNAs are under weaker selective constraints than protein-coding genes, and many are primate specific
Some human lncRNA genes belong to evolutionary conserved families that evolve faster than protein-coding genes. In this process, sequence similarity seems to be preserved mainly in regions involved in secondary structure formation

lncRNA long non-coding RNA