A novel sRNA population of unknown biogenesis from an intergenic region. (A) Screenshot of the reads profile of the mature small RNA populations matching an intergenic region in the chromosome 2 (chr2: 29.039-29.123), with reads belonging to the five small RNA libraries. (B) Validation of the sRNAs expression by low molecular weight Northern blotting. Total RNA was extracted from cell cultures grown under different light conditions (High Light (HL), Normal Light (NL), Low Light (LL), Dark (D) and iron starvation (−Fe)) and Northern blots hybridized with radiolabeled probes recognizing the small 25 nt product and the U6 snRNA as reference loading control. M, microRNA Marker (New England Biolabs, USA).