A3 small RNA library
1ug of RNA was incubated with 5 RNA  polyphosphatase (Epicentre) at a final concentration of 1U/l at 37C for 1h  in a total volume of 20ul, to convert 5PPP 22G-RNAs into clonable 5P  22G-RNAs. RNA was phenol-chloroform extracted and precipitated overnight with  1l glycogen, 1/10 volume 3M AcNA and 3 volumes 100% ethanol. Small RNA  libraries were generated using the Illumina TruSeq Small RNA library  preparation kit as per manufacturers instructions, and gel-purified to size  select 21-23nt inserts