Genomic organization and mRNA expression of manganese superoxide dismutase (Mn-SOD) from Hemibarbus mylodon (Teleostei, Cypriniformes).
The genomic structure of manganese superoxide dismutase (Mn-SOD) was characterized in Hemibarbus mylodon (Teleostei, Cypriniformes), an endangered freshwater fish species, and changes in Mn-SOD mRNA expression in response to various stimuli, such as challenge with lipopolysaccharide (LPS), bacteria, or heavy metals, were examined. H. mylodon Mn-SOD possesses well-conserved features of vertebrate Mn-SODs, including its homologous quinquepartite gene structure (five exons interrupted by four introns) and high sequence identity with vertebrate orthologs in coding regions, including a typical eukaryotic Mn-SOD signature. The 5'-regulatory upstream region of the H. mylodon Mn-SOD gene lacked a canonical TATA sequence; however, it displayed various transcription factor binding elements that may be involved in immune and stress responses, as well as the modulation of enzymes that mediate the metabolism of metals and other xenobiotics. Bioinformatic analysis of Mn-SOD genes from fish and mammalian genome databases revealed chromosomal synteny of the Mn-SOD locus in the vertebrate lineage. Mn-SOD transcripts were ubiquitously detected in diverse tissues with variable levels of basal expression using an RT-PCR assay. Mn-SOD expression in the liver and kidney were significantly modulated by injection of LPS (1, 5, or 10 microg g(-1) body weight), Edwardsiella tarda challenge (5 x 10(3) or 5 x 10(5) cells/fish), and heavy metal exposure (Cd, Cu, or Zn at 5 microM). Results from this study suggest that Mn-SOD plays an important role in the host defence against oxidative damage caused by infection-mediated inflammation and/or toxicant related stress in this species.
Cho
Young Sun
YS
Department of Aquaculture, Pukyong National University, Busan 608-737, South Korea.
Lee
Sang Yoon
SY
Bang
In Chul
IC
Kim
Dong Soo
DS
Nam
Yoon Kwon
YK
D000595:Amino Acid Sequence; D000818:Animals; D003531:Cypriniformes / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D023281:Genomics; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D013482:Superoxide Dismutase