the raw reads of microRNA in Alexandrium catenella
Approximately 1 ?g of total RNA was used to prepare small RNA library according to protocol of TruSeq TM Small RNA Sample Preparation Kit (Illumina). Basically, fragments of 15-40 nt sRNAs were separated by 15% denaturing polyacrylamide gels electrophoresis (PAGE) according to TrackItTM 10 bp DNA Ladder (Invitrogen). Then synthesis of cDNA using SuperScript?Reverse  Transcriptase  (Life Technologies) was done following ligating 3'and 5'RNA adapters with T4 RNA ligase. Subsequently, the sRNAs were subjected to PCR amplification and the final amplification products of approximate 147 bp were further purified by 6% PAGE. Finally, Illumina Hiseq 2000 was operated to sequence the constructed two libraries directly.