Defense Responses to Short-term Hypoxia and Seawater Acidification in the Thick Shell MusselMytilus coruscus.
The rising anthropogenic atmospheric CO2results in the reduction of seawater pH, namely ocean acidification (OA). In East China Sea, the largest coastal hypoxic zone was observed in the world. This region is also strongly impacted by ocean acidification as receiving much nutrient from Changjiang and Qiantangjiang, and organisms can experience great short-term natural variability of DO and pH in this area. In order to evaluate the defense responses of marine mussels under this scenario, the thick shell musselMytilus coruscuswere exposed to three pH/pCO2levels (7.3/2800 μatm, 7.7/1020 μatm, 8.1/376 μatm) at two dissolved oxygen concentrations (DO, 2.0, 6.0 mg L-1) for 72 h. Results showed that byssus thread parameters, such as the number, diameter, attachment strength and plaque area were reduced by low DO, and shell-closing strength was significantly weaker under both hypoxia and low pH conditions. Expression patterns of genes related to mussel byssus protein (MBP) were affected by hypoxia. Generally, hypoxia reduced MBP1 and MBP7 expressions, but increased MBP13 expression. In conclusion, both hypoxia and low pH induced negative effects on mussel defense responses, with hypoxia being the main driver of change. In addition, significant interactive effects between pH and DO were observed on shell-closing strength. Therefore, the adverse effects induced by hypoxia on the defense of mussels may be aggravated by low pH in the natural environments.
Department of Biology, College of Fisheries and Life Science, Shanghai Ocean UniversityShanghai, China; Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation, Ministry of Agriculture of China, East China Sea Fisheries Research Institute, Chinese Academy of Fisheries SciencesShanghai, China.
Yanming
Y
Sui
Department of Biology, College of Fisheries and Life Science, Shanghai Ocean UniversityShanghai, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of EducationShanghai, China.
Yimeng
Y
Liu
Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation, Ministry of Agriculture of China, East China Sea Fisheries Research Institute, Chinese Academy of Fisheries Sciences Shanghai, China.
Xin
X
Zhao
Department of Biological and Environmental Sciences, Sven Lovén Centre for Marine Sciences, University of Gothenburg Fiskebäckskil, Sweden.
Sam
S
Dupont
Department of Biology, College of Fisheries and Life Science, Shanghai Ocean UniversityShanghai, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of EducationShanghai, China.
Menghong
M
Hu
Department of Biology, College of Fisheries and Life Science, Shanghai Ocean University Shanghai, China.
Fangli
F
Wu
Department of Biology, College of Fisheries and Life Science, Shanghai Ocean University Shanghai, China.
Xizhi
X
Huang
Department of Biology, College of Fisheries and Life Science, Shanghai Ocean UniversityShanghai, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of EducationShanghai, China.
Jiale
J
Li
Department of Biology, College of Fisheries and Life Science, Shanghai Ocean UniversityShanghai, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of EducationShanghai, China.
Weiqun
W
Lu
Department of Biology, College of Fisheries and Life Science, Shanghai Ocean UniversityShanghai, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of EducationShanghai, China.
Youji
Y
Wang
byssus; defense response; hypoxia; mussel; pH