Chemical Approaches for Structure and Function of RNA in Postgenomic Era

Table 4

Paradoxical characteristics of ncRNAs in humans and mice [50, 51]. The excessive number of transcripts than anticipated for 25,000 genes indicates that the ncRNAs which were not detected due to scarce abundance have been detected by more sensitive methods. Some of these characteristics are summarized.

	Human	Mouse
Gene Number	75,000, 84,000 or 140,000 (cDNA identified)
Transcripts		181,000
Population	50% Poly-A RNAs (of 16% genome)	50% transcripts (of 62% genome); (35% from antisense strand)
Intron	30% genome
Processing	Polyadenylation, 5′ cap, splicing, nucleotide modification
Transcripts from	Intergenic, Intronic regions and antisense strand
Short ncRNAs	miRNA, siRNA (tasiRNA, natsiRNA), piRNA, rasiRNA (pitRNA), PARs (PROMTs, PASRs, TSSa-RNAs, tiRNAs), MSY-RNA, snoRNA, sdRNA, moRNA, tel-sRNA, crasiRNA, hsRNA, scaRNAs, AluRNA, YRNA, tRNA-derived RNAs
Long ncRNA (lncRNA) (0.5–100 kb)	Cancers, disorders in skin, heart, brain, cerebellum, and so forth. TR/TERC, NEAT RNA (NEAT1v-1, NEAT1v-2, NEAT2/MALAT1), PINC RNA, DD3/PCA3, PCGEM1, SPRY4-1T1, xiRNAs (Xist RNA, Tsix RNA, RepA RNA), AIR, H19, KCNQ1ot1, HOTAIR, BORG, CTN RNA, ANRIL RNA, LINE, CSR RNA, satellite DNA transcripts and so forth
Function	Regulatory function in all aspects of metabolism [52]