AN UPDATE ON THE MicroRNAs AND THEIR TARGETS IN UNICELLULAR RED ALGA PORPHYRIDIUM CRUENTUM

MicroRNAs (miRNAs) are small, non-coding and regulatory RNAs about approximate to 21 nucleotides in length. The miRNAs are reported in large number of higher eukaryotic plant species. But very little data of miRNAs in algae is available. Porphyridium cruentum is unicellular red alga famous as a source for polyunsaturated fatty acids, proteins and polysaccharide contents. The present study is aimed to update the microRNAs and their targets in this important algal species. A comparative genomics approach was applied to update the miRNAs in P. cruentum. This effort resulted in a total of 49 miRNAs belonging to 46 families in P. cruentum. Their precursor-miRNAs were observed with a range of 40 to 351 nucleotides (nt). The mature miRNA sequences showed a range of 17-24 nts. The minimum free energies by stem loop structures of these miRNAs are found with an average of -32 Kcalmol(-1). A total of 13 targets, including important proteins like; Ribulose-1,5-bisphosphate carboxylase oxygenase, Light-harvesting complex I, Oxygen-evolving enhancer protein, Phycobiliproteins, Granule-bound starch synthase and Carbonic anhydrase were also predicted for these miRNAs.