Assessment of hypoxia-inducible factor-1α mRNA expression in mantis shrimp as a biomarker of environmental hypoxia exposure.
Efforts to assess the ecological impacts of the marked increase in coastal hypoxia worldwide have been hampered by a lack of biomarkers of hypoxia exposure in marine benthic organisms. Here, we show that hypoxia-inducible factor-1α (HIF-1α) transcript levels in the heart and cerebral ganglion of mantis shrimp (Oratosquilla oratoria) collected from hypoxic sites in Tokyo Bay are elevated several-fold over those in shrimp collected from normoxic sites. Upregulation of HIF-1α mRNA levels in the heart after exposure to sub-lethal hypoxia was confirmed in controlled laboratory experiments. HIF-1α transcript levels were increased at approximately threefold after 7 and 14 days of hypoxia exposure and declined to control levels within 24 h of restoration to normoxic conditions. The results provide the first evidence for upregulation of HIF-1α transcript levels in two hypoxia-sensitive organs, heart and cerebral ganglion, in a marine invertebrate exposed to environmental hypoxia. These results suggest that upregulation of HIF-1α transcript levels is an important component in adaptation of mantis shrimp to chronic hypoxia and is a potentially useful biomarker of environmental hypoxia exposure.
National Institute for Environmental Studies, Center for Environmental Risk Research, Tsukuba, Ibaraki, Japan. kodama.keita@04.alumni.u-tokyo.ac.jp
Keita
K
Kodama
Md Saydur
MS
Rahman
Toshihiro
T
Horiguchi
Peter
P
Thomas
D000595:Amino Acid Sequence; D000693:Anaerobiosis; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D003001:Cloning, Molecular; D003445:Crustacea / Q000235:genetics*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics* / Q000378:metabolism; D007564:Japan; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism; D010100:Oxygen / Q000032:analysis / Q000378:metabolism; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D013312:Stress, Physiological; D015854:Up-Regulation
D015415:Biomarkers; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D010100:Oxygen