title: Molecular cloning, mRNA expression and characterization of membrane-bound hemoglobin in oriental river prawn Macrobrachium nipponense.
abstract: Most hemoglobins are respiratory proteins and are ubiquitous in animals, bacteria, fungi, protists, and plants. In this study, we describe a membrane-bound hemoglobin in the oriental river prawn Macrobrachium nipponense (MnHb), which also expresses hemocyanin. MnHb cDNA was cloned using the rapid amplification of cDNA ends (RACE) approach, which afforded a 1201bp gene encoding a 193 amino acid polypeptide. Bioinformatic evaluation suggested MnHb is membrane anchored by N-myristoylation, and immunofluorescence confirmed its location in the membrane of chief cells in the gill. The effect of hypoxia on MnHb expression was investigated, and reverse transcription PCR (RT-PCR) and Western blotting showed that MnHb was expressed almost exclusively in the gill. Quantitative RT-PCR revealed a significant increase in expression after 6h of hypoxia, and levels peaked at 24h due to oxidative stress. Exposure of cultured prawns to the stress inducer H2O2significantly up-regulated the expression of MnHb in a dose-dependent manner. MnHb may have a role in protecting cell membrane lipids from damage by reactive oxygen species.
authors.affiliation: Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture, Freshwater Fisheries Research Centre, Chinese Academy of Fishery Sciences, Wuxi 214081, PR China.
authors.forename: Shengming
authors.initials: S
authors.lastname: Sun
authors.affiliation: Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Yancheng City, Jiangsu Province 224002, PR China.
authors.forename: Fujun
authors.initials: F
authors.lastname: Xuan
authors.affiliation: Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture, Freshwater Fisheries Research Centre, Chinese Academy of Fishery Sciences, Wuxi 214081, PR China. Electronic address: fuht@ffrc.cn.
authors.forename: Hongtuo
authors.initials: H
authors.lastname: Fu
authors.affiliation: Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture, Freshwater Fisheries Research Centre, Chinese Academy of Fishery Sciences, Wuxi 214081, PR China. Electronic address: zhuj@ffrc.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture, Freshwater Fisheries Research Centre, Chinese Academy of Fishery Sciences, Wuxi 214081, PR China.
authors.forename: Xianping
authors.initials: X
authors.lastname: Ge
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai 201306, PR China.
authors.forename: Xugan
authors.initials: X
authors.lastname: Wu
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005786:Gene Expression Regulation; D005880:Gills / Q000378:metabolism / Q000502:physiology; D006454:Hemoglobins / Q000235:genetics*; D000860:Hypoxia / Q000235:genetics; D008566:Membranes / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D033541:Palaemonidae / Q000235:genetics*; D010802:Phylogeny; D045483:Rivers
chemical_list: D018076:DNA, Complementary; D006454:Hemoglobins
keywords: Gill; Hypoxia; Macrobrachium nipponense; Membrane-bound hemoglobin; Oxidative stress