Solexa sequencing of small RNAs in Chinese Amphioxus

We applied Solexa sequencing technology to identify Amphioxus microRNA genes. We identified 113 amphioxus microRNA genes, 55 were conserved across species and coded for 45 nonredundant mature miRNAs, whereas 58 were amphioxus-specific and accounted for 53 mature miRNAs. Analyzing the evolutionary history of amphioxus miRNAs, we found amphioxus possessed many miRNAs that are also found in chordates and vertebrates, suggesting these miRNAs may represent cephalochordate lineage innovation. By detailed comparison of the miRNA phylogenetic histories, we further found that amphioxus is more vertebrate-like than tunicates. Keywords: Small RNA Overall design: 18-30 nt small RNAs from 12 adult Chinese Amphioxus were sequenced in one Solexa lane.