Small RNA Expression Profiling by High-Throughput Sequencing: Implications of Enzymatic Manipulation

Table 1

Classes of small RNAs and their 5′- and 3′-end modifications.

Class	Organism	5′-end modification	3′-end modification
miRNA	Mammals	Monophosphate	2′OH
	Nematodes	Monophosphate	2′OH
	Insects	Monophosphate	2′OH
	Plants	Monophosphate	2′-O-methyl
siRNA	Mammals	Monophosphate	2′OH
	Nematodes	Monophosphate	2′OH
	Insects	Monophosphate	2′-O-methyl
	Plants	Monophosphate	2′-O-methyl
Secondary siRNA	Nematodes	Polyphosphate	2′OH
	Plants	Monophosphate	2′-O-methyl
piRNA	Mammals	Monophosphate	2′-O-methyl
	Nematodes	Monophosphate	2′-O-methyl
	Insects	Monophosphate	2′-O-methyl

For references, see text and [4].