Production traits and fertility of reciprocal hybrids between Argopecten irradians irradians and A.i.concentricus

The two bay scallop subspecies,Argopecten irradians irradians(NN)and A.i.concentricus(SS),are fast growing and major cultured bivalves in China.However,their relatively small sizes and decreasing production traits caused by long-term inbreeding have been major concerns to the industry in the last two decades.Hybridization between the two bay scallop subspecies may provide a new approach to breed a new variety with superior production traits for the industry.For this end,in this study,we hybridized the two bay scallop subspecies in order to obtain a new strain that incorporates the genes of both subspecies.No significant difference was found in fertilization rate,hatching rate and metamorphosis rate between the purebred and crossbred cohorts(NN♀×SS♂,denoted as NS;SS♀×NN♂,denoted as SN).Both mating strategy(intra-vs.inter-population crosses)and egg origin had significant effects on growth and survival at the larval stage.Heterosis was observed in the crossbred and was more pronounced in older stages.Genetic diversity of the reciprocal hybrids,especially that of SN,was increased compared with the purebred cohorts.Almost all hybrids were completely fertile and able to reproduce by selffertilization or by backcrossing with either parent.Apparently,male sterile individuals whose gonads were fully occupied by the ovary part at mature stage were found in the hybrids for the first time.The hybrids,especially SN,may provide precious germplasm resources for the production of ternary hybrids with the Peruvian scallop,A.purpuratus.

LncRNA pol-lnc78 as a ceRNA regulates antibacterial responses via suppression of pol-miR-n199-3p-mediated SARM down-regulation in Paralichthys olivaceus

Long non-coding RNAs(lncRNAs)function as key modulators in mammalian immunity,particularly due to their involvement in lncRNA-mediated competitive endogenous RNA(ceRNA)crosstalk.Despite their recognized significance in mammals,research on lncRNAs in lower vertebrates remains limited.In the present study,we characterized the first immune-related lncRNA(pol-lnc78)in the teleost Japanese flounder(Paralichthys olivaceus).Results indicated that pol-lnc78 acted as a ceRNA for pol-miR-n199-3p to target the sterile alpha and armadillo motif-containing protein(SARM),the fifth discovered member of the Toll/interleukin 1(IL-1)receptor(TIR)adaptor family.This ceRNA network regulated the antibacterial responses of flounder via the Toll-like receptor(TLR)signaling pathway.Specifically,SARM acted as a negative regulator and exacerbated bacterial infection by inhibiting the expression of inflammatory cytokines IL-1βand tumor necrosis factor-α(TNF-α).Pol-miR-n199-3p reduced SARM expression by specifically interacting with the 3’untranslated region(UTR),thereby promoting SARM-dependent inflammatory cytokine expression and protecting the host against bacterial dissemination.Furthermore,pol-lnc78 sponged pol-miR-n199-3p to ameliorate the inhibition of SARM expression.During infection,the negative regulators pol-lnc78 and SARM were significantly down-regulated,while pol-miR-n199-3p was significantly up-regulated,thus favoring host antibacterial defense.These findings provide novel insights into the mechanisms underlying fish immunity and open new horizons to better understand ceRNA crosstalk in lower vertebrates.

Optimization of conditions for tetraspore release and assessment of photosynthetic activities for different generation branches of Gracilaria lemaneiformis Bory

Gracilaria lemaneiformis Bory is an economically important alga that is primarily used for agar production.Although tetraspores are ideal seeds for the cultivation of G.lemaneiformis,the most popular culture method is currently based on vegetative fragments,which is labor-intensive and time-consuming.In this study,we optimized the conditions for tetraspore release and evaluated the photosynthetic activities of different colonies formed from the branches of G.lemaneiformis using a PAM(pulse-amplitude-modulated) measuring system.The results showed that variations in temperature and salinityhad significant effects on tetraspore yield.However,variations in the photon flux density(from 15 μmol m-2 s-1 to 480 μmol m-2 s-1) had no apparent effect on tetraspore yield.Moreover,the PAM-parameters Y(I),Y(Ⅱ),ETR(I),ETR(Ⅱ) and Fv/Fm of colonies formed from different branches showed the same trend:parameter values of first generation branches>second generation branches>third generation branches.These results suggest that the photosynthetic activities of different colonies of branches changed with the same trend.Furthermore,photosynthesis in G.lemaneiformis was found to be involved in vegetative reproduction and tetraspore formation.Finally,the first generation branches grew slowly,but accumulated organic compounds to form large numbers of tetraspores.Taken together,these results showed that the first generation branches are ideal materials for the release of tetraspores.

The satellite reversion of dissolved organic carbon (DOC) based on the analysis of the mixing behavior of DOC and colored dissolved organic matter: the East China Sea as an example

The retrieval of dissolved organic carbon （DOC） distribution by remote sensing is mainly based on the em- pirical relationship of DOC concentration and colored dissolved organic matter （CDOM） concentration in many literatures. To investigate the nature of this relationship, the distributions and mixing behaviors of DOC and CDOM are reviewed in the world＇s major estuaries and bays. It is found that, generally, the C- DOM concentration is well correlated with the salinity in most estuaries, while DOC usually shows a non- conservative behavior which leads to a weak correlation between the DOC concentration and the CDOM concentration. To establish a good satellite reversion of the DOC concentration, the East China Sea（ECS） was taken as an example, and the mixing behavior of DOC and CDOM as well as the influence of biogeo- chemical processes were analyzed except for the physical mixing process with the data from late autumn （November, 2010） and winter （December, 2009） cruises. In the two ECS cruises, the CDOM concentration was found to be tightly correlated with the salinity, influenced little by the photochemical or biological pro- cesses. The data from the winter cruise show that DOC followed a conservative mixing along the salinity gradient, while in the late autumn cruise it was significantly affected by the biological activities, resulting in a poor correlation between the DOC and the CDOM. Accordingly, an improved DOC algorithm （CSDM） was proposed： when the biological influence was significant （Chl a greater than 0.8 μg/dm3）, DOC was retrieved by the conservative and biological model, and if the conservative mixing was dominant （Chl a less than 0.8 μg/dm3）, the direct DOC concentration and CDOM concentration relationship was used. Based on the pro- posed algorithm, a reasonable DOC distribution for the ECS from satellite was obtained in this study, and the proposed method can be applied to the other large river-dominant marginal sea.

Phase Equilibrium and Phase Diagram of the Ternary System（MgCl2 + MgB2O4 + H2O） at 288 and 298 K

1 Introduction The brines with high concentrations of magnesium and boron resources are widely distributed in the Qaidam Basin of the Qinghai-Tibet plateau,China(Zheng&Tang,1988).Although some works on the ternary system

Production of polyhydroxybutyrate by the marine photosynthetic bacterium Rhodovulum sulfidophilum P5

The effects of different NaCl concentrations, nitrogen sources, carbon sources, and carbon to nitrogen molar ratios on biomass accumulation and polyhydroxybutyrate （PHB） production were studied in batch cultures of the marine photosynthetic bacterium Rhodovulum sulfidophilum P5 under aerobic-dark conditions. The results show that the accumulation of PHB in strain P5 is a growth-associated process. Strain P5 had maximum biomass and PHB accumulation at 2%-3% NaCl, suggesting that the bacterium can maintain growth and potentially produce PHB at natural seawater salinity. In the nitrogen source test, the maximum biomass accumulation （8.10±0.09 g/L） and PHB production （1.11±0.13 g/L and 14.62%±2.25% of the cell dry weight） were observed when peptone and ammonium chloride were used as the sole nitrogen source. NH^-N was better for PHB production than other nitrogen sources. In the carbon source test, the maximum biomass concentration （7.65±0.05 g/L） was obtained with malic acid as the sole carbon source, whereas the maximum yield of PHB （5.03±0.18 g/L and 66.93%± 1.69% of the cell dry weight） was obtained with sodium pyruvate as the sole carbon source. In the carbon to nitrogen ratios test, sodium pyruvate and ammonium chloride were selected as the carbon and nitrogen sources, respectively. The best carbon to nitrogen molar ratio for biomass accumulation （8.77±0.58 g/L） and PHB production （6.07±0.25 g/L and 69.25%±2.05% of the cell dry weight） was 25. The results provide valuable data on the production of PHB by R. sulfidophilum P5 and further studies are on-going for best cell growth and PHB yield.

Integrated transcriptome and physiology analysis of Microcystis aeruginosa after exposure to copper sulfate

Copper sulfate(CuSO4)is widely used in controlling the Microcystis aeruginosa blooms.Many studies reported the toxicity mechanisms of Cu^2+to M.aeruginosa at the physiological level,but little is known about a transcriptomic basis of these mechanisms.In the present study,M.aeruginosa was treated by 0.5 mg/L Cu^2+(half of the 96-h EC50)for 72 h.The results show that CH2+content in M.aeruginosa increased after 72 h Cu^2+exposure,whereas the Fv/Fm chlorophyll fluorescence value and chlorophyll a content in M.aeruginosa sharply decreased.Reactive oxygen species concentration and activity of antioxidant enzymes(superoxide dismutase,catalase and peroxidase)were all increased.These physiological data confirmed toxicity of Cu^2+to m.aeruginosa.The RNA-seq analysis showed that 6646725 and 7880291 clean reads were obtained for the Cu-treated and control libraries,respectively.The 595 genes(252 downward trend and 343 upward trend)with the Gene Ontology(GO)annotations were divided into three main functional categories:cellular component,molecular function,and biological process.In the Cluster of Orthologous Groups(COG)annotation,418 differentially expressed genes with 25 functional definitions were obtained.Among them,‘replication,recombination and repair’,‘energy production and conversion’,and‘general function prediction only’were the largest three groups of transcripts.In the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis,genes involved in photosynthesis and oxidative phosphorylation were present at the highest percentages.In addition,the genes involved in photosynthesis and oxidative phosphorylation were identified,and then confirmed using real-time PCR.This study reported the first transcriptome of M.aeruginosa.Photosynthesis and oxidative phosphorylation were severely affected by Cu^2+toxicity,which may have contributed to cell death.These data provide the potential mechanism to explain the CuSO4 effect on the harmful M.aeruginosa.

Coupling of an Individual-Based Model of Anchovy with Lower Trophic Level and Hydrodynamic Models

Anchovy （Engraulis aponicus）, a small pelagic fish and food of other economic fishes, is a key species in the Yellow Sea ecosystem. Understanding the mechanisms of its recruitment and biomass variation is important for the prediction and management of fishery resources. Coupled with a hydrodynamic model （POM） and a lower trophic level ecosystem model （NEMURO）, an individual-based model of anchovy is developed to study the influence of physical environment on anchovy＇s biomass variation, Seasonal variations of circulation, water temperature and mix-layer depth from POM are used as external forcing for NEMURO and the anchovy model. Biomasses of large zooplankton and predatory zooplankton which anchovy feeds on are output from NEMURO and are controlled by the consumption of anchovy on them. Survival fitness theory related to temperature and food is used to determine the swimming action of anchovy in the model. The simulation results agree well with observations and elucidate the influence of temperature in over-wintering migration and food in feeding migration.

Photosynthetic responses of thalli and isolated protoplasts of Bryopsis hypnoides(Bryopsidales,Chlorophyta)during dehydration

Bryopsis kypnoides Lamouroux is a unique intertidal siphonous green alga whose extruded protoplasm can aggregate spontaneously in seawater to form numerous new cells that can develop into mature algal thalli. In this study, the photosynthetic responses during dehydration of both the thalli and protoplasts isolated from B. kypnoides were measured using a Dual-PAM （pulse amplitude modulation）-100 fluorometer. The results show that the photosynthetic rates of B. kypnoides thalli were maintained for an initial period, beyond which continued desiccation resulted in reduced rates of PSI and PSII. However, the photosynthetic performances of the isolated protoplasts dehydrated in air （CO2 concentration 600-700 mg/L） showed a slight increase of Y（II） at 20% water loss, but the rates decreased thereafter with declining water content. When protoplasts were dehydrated in CO2 deficient conditions （CO2 concentration 40-80 mg/L）, the values of Y（II） declined steadily with increased dehydration without an initial rise. These results indicated that the thalli and isolated protoplasts of this alga can utilize CO2 in ambient air effectively, and the photosynthetic performances of the isolated protoplasts were significantly different from that of the thalli during dehydration. Thus the protoplasts may be an excellent system for the study of stress tolerance.

Involvement of cyclic electron flow in irradiance stress responding and its potential regulation of the mechanisms in Pyropia yezoensis

Pyropia yezoensis, belongs to the genus of P orphyra before 2011, inhabit on intertidal zone rocks where irradiation changes dramatically, implying that the seaweed has gained certain mechanisms to survive a harsh environment. Based on the photosynthetic parameters with or without the inhibitors determined by a Dual-PAM-100 apparatus, we investigated the photosynthetic performance and the changes in electron fl ow that occurred during the algae were stressed with dif ferent light intensities previously. When the irradiation saturation was approaching, the CEF around PS I became crucial since the addition of inhibitors usually led to an increase in non-photochemical quenching. The inhibitor experiments showed that there were at least three dif ferent CEF pathways in Py. yezoensis and these pathways compensated each other. In addition to maintaining a proper ratio of ATP/NAD(P)H to support effi cient photosynthesis, the potential roles of CEF might also include the regulation of dif ferent photoprotective mechanisms in Py. yezoensis. Under the regulation of CEF, chlororespiration is thought to transport electrons from the reduced plastoquinone(PQ) pool to oxygen in order to mitigate the reduction in the electron transfer chain. When irradiation was up to the high-grade stress conditions, the relative value of CEF began to decrease, which implied that the NADP+ pool or PQ + pool was very small and that the electrons were transferred from reduced PS I to oxygen. The scavenging enzymes might be activated and the water-water cycle probably became an ef fective means of removing the active oxygen produced by the irradiation stressed Py. yezoensis. We believe that the dif ferent mechanisms could make up the photoprotective network to allow Py. yezoensis for survival in a highly variable light stress habitat, which may enlighten scientists in future studies on irradiance stress in other algae species.

Vertical and horizontal displacements of a reservoir slope due to slope aging effect,rainfall,and reservoir water

Landslides are common hazards in reservoir areas and significantly affect dam operation and human lives.For the prevention and management of landslides,accurate assessment of the factors influencing their generation is essential.This study evaluated the key external factors influencing horizontal and vertical displacements of Luobogang Reservoir Slope in Hanyuan County,China.Displacements had been monitored by a surface-displacement-monitoring system consisting of 118 GPS stations during 2012-2015.To identify the external driving factors,their influence zones,and slope responses,we analyzed 32 months of displacement measurements and other multi-source datasets using the empirical orthogonal function.Overall,the results show that slope aging effect,rainfall,and reservoir water levels are three main driving factors.For horizontal displacement,aging effect is the most critical factor and predominantly affects the edges of landslides,the gob cave,and the public building zones.The secondary factor is the reservoir water level,which mainly acts on the boundary between the slope and reservoir water surface.The closer the slope zone is to the reservoir water,the more significant the impact is.Regarding vertical displacement,the most important factor is rainfall.The vertical displacement caused by rainfall accounts for 56.76% of the total vertical displacements.However,rainfall induces elastic displacements that generally cause less damage to the slope.The secondary factor is aging effect,and the vertical displacement caused by aging effect accounts for 9.42%.However,seven individual zones are highly affected by slope aging effect,which is consistent with the distribution of public buildings.

Phase Equilibria of the Aqueous Systems Containing Lithium and Carbonate Ions

1 Introduction Alkaline lakes are widely distributed in the area of the Qinghai-Tibet Plateau.Most of the salt lakes are famous for their high concentration of lithium,potassium,magnesium,boron(Ma,2000).In recent years,as a new energy material,lithium and its compounds are widely used in the new area,such as aerospace industry,nuclear

Analysis of DNA methylation in different tissues of Fenneropenaeus chinensis from the wild population and Huanghai No. 1

DNA methylation plays an important role in the regulation of gene expression during biological development and tissue differentiation in eukaryotes. A methylation sensitive amplification polymorphism（MSAP） including digestion, pre-selective amplification and selective amplification was optimized to compare the levels of DNA cytosine methylation at CCGG sites in muscle, gill and hemocyte from the wild populations and the selective breeding of Huanghai No. 1 of Fenneropenaeus chinensis, respectively. Significant differences in cytosine methylation levels among three tissues in two populations were detected. The average DNA methylation ratios in muscle, gill and hemocyte of the wild population were 23.1%, 22.3% and 19.7%, while those were 21.4%, 19.6%,and 18.9% in Huanghai No. 1, respectively. The DNA methylation levels of gill from the two populations were highly significant（P〈0.01）, the difference of muscle was significant（P〈0.05）, while in hemocyte, there were no significant differences（P〉0.05）. DNA polymorphic methylation of gill and hemocyte between the wild population and Huanghai No. 1 varies to some extent, while those of muscle kept in a balanced degree. Furthermore,polymorphic methylation was associated with demethylation and methylation of CCGG loci.

Precipitation scale effect of the TRMM satellite in Tianshan,China

High-resolution precipitation data is conducive to objectively describe the spatial-temporal variability of regional precipitation,and the study of downscaling techniques and spatial scale effects can provide technical and theoretical support to improve the spatial resolution and accuracy of satellite precipitation data.In this study,we used a machine learning algorithm combined with a regression algorithm RF-PLS(Random Forest-Partial Least Squares)to construct a downscaling model to obtain three types of high-resolution TRMM(Tropical Rainfall Measuring Mission)downscaled precipitation data for the years 2000-2017 at 250 m,500 m,and 1km.The scale effects with topographic and geomorphological features in the study area were analysed.Finally,we described the spatial and temporal variation of precipitation based on the optimal TRMM downscaled precipitation data.The results showed that:1)The linear relationships between the TRMM downscaled precipitation data obtained by each of the three downscaled models(PLS,RF,and RF-PLS)and the precipitation at the observation stations were improved compared to the linear relationships between the original TRMM data and the precipitation at the observation stations.The accuracy of the RF-PLS model was better than the other two models.2)Based on the RF-PLS model,the resolution of the TRMM data was increased to three different scales(250 m,500 m,and 1 km),considering the scale effects with topographic and geomorphological features.The precipitation simulation effect with a spatial resolution of 500 m was better than the other two scales.3)The annual precipitation was the highest in the areas with extremely high mountains,followed by the mediumhigh mountain,high mountain,medium mountain,medium-low mountain,plain,low mountain,and basin.

Effects of Bioflocs on Artemia Growth and Water Quality

1 Introduction Bioflocs is a heterogeneous mixture of the microorganisms,particles,organic polymers and dead cells,etc.(Hargreaves,2006).Among which,heterotrophic bacteria convert efficiently the ammonia nitrogen into the bacterial protein,which provides the supplementary feed for culture animals and reduces the nitrogen level in the culture system(De Schryver et al,2008).In the closed aquaculture system,the growth of

Regime shifts of hydrometeorological factors in the Jiaozhou Bay and their potential ecological impacts

The wavelet transform was applied to studying the regime shifts of hydrometeorological factors(i.e.,precipitation,air temperature,sea surface temperature and sea surface salinity)during the period of 1961–2000 in the Jiaozhou Bay(JZB).The results indicated clearly that these factors show variability of multiple timescales,with interannual and decadal periods.The local abrupt changes such as the 1978–1979 and 1988–1989 shifts feature the physical environment variation,which is consistent with the Southern Oscillation and Arctic Oscillation in the northern hemisphere.In regard to the JZB ecosystem,the benthic diatom cell abundance(BEN)showed a decrease shift in1978–1979,which is closely related to the precipitation abrupt decrease,while the shellfish mortality disaster in the JZB greatly released the predating pressure of diatom growth,possibly resulting in BEN increase shift in 1995.

Effects of Salinity and Temperature on Bacterial Biodiversity in Hangu Solar Saltworks,China

1 Introduction The multi-pond solar saltworks inhabit diverse microbial groups in which a gradient of salinities range from seawater to Na Cl precipitation.Along the salinity gradient,the majority of microbial community changes

Research of Recycled Salt and Glauber' Salt Precipitation Rules of Yabulai Salt Lake Brine

1 Introduction The main production of Yabulai salt lake was original salt and recycled salt many years ago.After decade’s production,the sale lake resource is more and more deficient.Glauber’s salt and magnesium salt are concentrated in brine now.It could affect the quality of the salt.In recent years,research had done much work to

Synthesis and Characterization of an Extractant [Bmim]PF_6 for Lithium Ion

With the rapid increasing demand of metal lithium and its compounds in science and technology,studies on lithium recovery though lithium ion extraction from salt lake brines are blooming bacause more than 60 percent of

Phase Equilibria of Salt-water Systems Containing Magnesium and Borate Ions

1 Introduction A salt lake is a naturally occurring complex body of water and salt interaction.More than 700 salt lakes are widely distributed in the area of the Qinghai-Tibet Plateau.Most of the salt lakes are famous for their abundance of lithium,potassium,magnesium,and boron resources.It is