Molecular cloning,characterization and expression analysis of mitochondrial manganese superoxide dismutase of an oriental river prawn,Macrobrachium nipponense

A mitochondrial manganese superoxide dismutase (mtmnsod) gene was cloned from the hepatopancreas of macrobrachium nipponense using the rapid amplification of cdna ends (race) method. the full-length cdna of mtmnsod was 1113 bp with a 654 bp of open reading frame encoding a 218 amino acid (aa) protein with a 21 aa signal peptide sequence in the n-terminus. the calculated molecular mass of the translated protein of mtmnsod was 31.33 kda with an estimated pi of 7.12. the deduced amino acid sequence of mtmnsod had similarity of 97%,88% and 86% to the mtmnsod of the macrobrachium rosenbergii,marsupenaeus japonicus and fenneropenaeus chinensis,respectively. the mmtmnsod contained a manganese superoxide dismutase domain (dvwehayy),four conserved amino acids responsible for binding manganese,and two n-glycosylation sites. real-time rt-pcr analysis showed that the mtmnsod mrna from m. nipponense was expressed in hepatopancreas,muscle,haemocytes,ovary,mandibular organ and gill,but relatively higher in the hepatopancreas. the highest levels of mtmnsod transcripts in hepatopancreas were in stage c among the molt cycle. injection of pathogenic bacteria aeromonas hydrophila resulted in the significant increase in mtmnsod expressions 3 h after treatment,indicating that mnsod may act as an important molecule involved in immune defense against a. hydrophila. copyright 2015 zoological society of pakistan.