Owing to population growth and environmental pollution, freshwater aquaculture has been rapidly shrinking in recent years. Aquaculture in saline-alkaline waters is a crucial strategy to meet the increasing demand for aquatic products. The Chinese mitten crab is an important economic food in China, but the molecular mechanism by which it tolerates carbonate alkalinity (CA) in water remains unclear. Here, we found that enzyme activities of the tricarboxylic acid (TCA) cycle in the gills, such as citrate synthase, isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, and malate dehydrogenase, were markedly reduced under CA stress induced by 40 mM NaHCO3. Secondly, the TCA cycle in the gills is inhibited under acute CA stress, according to proteomic and metabolomic analyses. The expressions of six enzymes, namely aconitate hydratase, isocitrate dehydrogenase, 2-oxoglutarate dehydrogenase, dihydrolipoyl dehydrogenase, succinate-CoA ligase, and malate dehydrogenase, were downregulated, resulting in the accumulation of phosphoenolpyruvic acid, citric acid, cis-aconitate, and α-ketoglutaric acid. Finally, we testified that if the TCA cycle is disturbed by malonate, the survival rate increases in CA water. To our knowledge, this is the first study to show that the TCA cycle in the gills is inhibited under CA stress. Overall, the results provide new insights into the molecular mechanism of tolerance to saline-alkaline water in crabs, which helped us expand the area for freshwater aquaculture and comprehensively understand the physiological characteristics of crab migration.
Brachyura , Carbonates , Citric Acid Cycle , Gills , Stress, Physiological , Animals , Citric Acid Cycle/drug effects , Gills/metabolism , Gills/drug effects , Brachyura/metabolism , Brachyura/physiology , Brachyura/drug effects , Carbonates/pharmacology
To explore food composition of Chinese mitten crab (Eriocheir sinensis) in rice-crab integrated ecosystem in saline-alkali land of the Yellow River Delta, we analyzed carbon and nitrogen stable isotope ratios (δ13C and δ15N) in the crab and that in food sources, including plants (Elodea, Potamogeton crispus, Ceratophyllum demersum, Lemna minor, Oryza sativa stem and leaf, rice grain), animals (benthos, zooplankton), organic debris and artificial feed (compound feed, corn meal) in Kenli District, Dongying, Shandong Province in June to October of 2020. Substantial differences in δ13C and δ15N were found among food sources. The δ13C and δ15N values of different food sources were in a range of -30.09--11.24 and 0.03-12.78, respectively, while those of the crab muscle were in range of -24.61--20.08 and 4.74-9.21, respectively, indicating diverse food sources for the crab. During the experiment, the contribution rate of different food sources followed the order: plant (46.7%-57.1%)>animal (21.5%-24.5%)>artificial feed (10.9%-21.3%)>organic detritus (7.1%-7.9%). It suggested that the natural bait of the paddy field could meet the feeding needs of Chinese mitten crabs in saline-alkali land. Even the crabs were fed with non-animal artificial feed, the contribution rates of the main food sources were not altered.
Oryza , Rivers , Alkalies , Animals , Carbon Isotopes/analysis , Ecosystem , Nitrogen Isotopes/analysis
We sequenced and characterized the complete mitochondrial genome from normal colour (grey black) and mutant colour (orangey red) of Luciobarbus capito. Both mitogenomes contained the typical complement of 13 protein-coding genes, 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs), and a non-coding control region. They share the same gene arrangement pattern that was identical with most vertebrates. The entire mitochondrial DNA molecule of grey black L. capito was 16603-bp long, while the complete mtDNA molecule of orangey red L. capito was 16607-bp long.
We sequenced and characterized the complete mitochondrial genome of golden yellow snakehead fish, Channa argus. The mitogenomes contained the typical complement of 13 protein-coding genes, 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs), and a non-coding control region. They share the same gene arrangement pattern that was identical with most vertebrates. The entire mitochondrial DNA molecule of golden yellow snakehead fish was 16,558 bp long. All information reported in this article will be a useful source of sequence information for general molecular and evolutionary studies of the family Channidae.
OBJECTIVE: To study the changes of sleep architecture and blood oxygen saturation (SaO(2)) during sleep in men living at high altitude, and to investigate the effect of rhodiola and acetazolamide on these sleep indexes. METHODS: Twenty-four men aged 18 to 21 years who had stayed at high altitude (5 380 m above sea level) for 1 year were randomly divided into groups A (treated with oral rhodiola), B (treated with oral acetazolamide) and C (treated with rhodiola + acetazolamide). Their sleep architecture and SaO(2) were recorded for 24 days before and after taking the medicines. RESULTS: Compared with baseline, the waking SaO(2) (WSaO(2)), the lowest SaO(2) (LSaO(2)) and the mean SaO(2) (MSaO(2)) were increased significantly after treatment for 24 days (P < 0.01), and the times of oxygen desaturation >/= 4% per hour (DI4) and the percentage of time spent at SaO(2) below 80% (SIT(80)) were decreased significantly (P < 0.01). After treatment, the NREM I and II was shortened, and III + IV and REM sleep were prolonged (P < 0.01): the total waking time (TWT) was shortened, and the sleep efficiency index (SEI) was markedly increased (P < 0.01). Compared with group A's, groups B's and C's SIT(80) were increased (P < 0.05). CONCLUSION: Both rhodiola and acetazolamide were effective in modulating the sleep architecture and improving the sleep quality in young men living at high altitude, but there was no synergistic effect between rhodiola and acetazolamide.
Acetazolamide/pharmacology , Altitude , Oxygen/blood , Rhodiola , Sleep/drug effects , Adolescent , Adult , Humans , Male
