miRNA expression in OSS cells. (A) OSS cells predominantly express a characteristic population of miRNAs (left) that overlaps only partially with the most abundant miRNAs annotated from across Drosophila development using 454 Life Sciences (Roche) sequencing (Ruby et al. 2007a). However, analysis of all reads indicates that the 454-annotated miRNAs and OSS miRNAs are very highly overlapping (right). Therefore, numerous ostensibly tissue-specific Drosophila miRNAs were captured at low levels in OSS cells by deep sequencing. (B) Five novel miRNA loci, expressed at a level of more than five reads/14 million library reads, were identified in OSS cells. Mature products were highlighted in green, and star strands in red; for some hairpins, the two small RNA products were cloned nearly equivalently.
