Characterization of a ribosomal protein L15 cDNA from Chironomus riparius (Diptera; Chironomidae): Transcriptional regulation by cadmium and silver nanoparticles

A full-length ribosomal protein L15 cDNA from Chironomus riparius (CrRPL15) was identified from the Expressed Sequence Tag (EST) database developed vt 454 pyrosequencing, and expression of the corresponding mRNA was analyzed during different developmental stages and following exposure to Cadmium chloride (Cd) and Silver nanoparticles (AgNPs). The CrRPL15 cDNA contains an open reading frame (ORF) of 615 base pairs (bp) encoding a putative protein of 204 amino acids, with a high level of sequence similarity to RPL15 proteins from other species. The consensus sequence, GXXXXGKS, which is present in other RPL15 proteins, was also present in the putative CrRPL15 protein. The CrRPL15 transcript was present at all life stages, but was most abundant in the eggs. Expression of the CrRPL15 gene was significantly down-regulated in response to exposure to both Cd and AgNPs. In contrast, expression of the heat shock protein 70 (HSP70) gene, a general stress indicator, was significantly up-regulated.