Chromosome-level genome assembly and annotation of the cold-water species Ophiura sarsii.

The cold-water species Ophiura sarsii, a brittle star, is a key echinoderm in the Arctic continental shelf region, highly sensitive to climate change. However, the absence of a high-quality genome has hindered a thorough understanding of its adaptive evolution. In this study, we reported the first chromosome-level genome assembly of O. sarsii. The genome assembly totalled 1.57 Gb, encompassing 19 chromosomes with a GC content of 37.11% and a scaffold N50 length of 78.03 Mb. The Benchmarking Universal Single-Copy Orthologs (BUSCO) assessment yielded a completeness estimate of 93.5% for this assembly. We predicted a total of 27,099 protein-coding genes, with 25,079 functionally annotated. The genome was comprised of 58.09% transposable elements. This chromosome-level genome of O. sarsii contributes to our understanding of the origin and evolution of marine organisms.

Dynamics of green macroalgal micro-propagules and the influencing factors in the southern Yellow Sea, China.

Micro-propagules (banks of microscopic forms) play important roles in the expansion of green tides, which are spreading on eutrophic coasts worldwide. In particular, large-scale green tides (Yellow Sea Green Tide, YSGTs) have persisted in the Yellow Sea for over 15 years, but the dynamics and functions of micro-propagules in their development remain unclear. In the present study, year-round field surveys were conducted to identify the reservoirs and investigate the persistence mechanisms and associated biotic and abiotic factors driving the temporal and spatial variations of micro-propagules. Micro-propagules in the southern Yellow Sea (SYS) showed evident spatial heterogeneity in terms of seasonal patterns and major influencing factors. Offshore of the SYS, the micro-propagule population underwent ephemeral expansion along with a large-scale bloom of floating Ulva algae in late spring and early summer. The Subei Shoal, particularly the sediments in the central raft region, had the highest micro-propagule abundance (MA) and was a major reservoir. The pronounced seasonal variation of MA in the Subei Shoal was primarily associated with the attached Ulva algae on Neopyropia aquaculture rafts. Vast aquaculture rafts provided essential substrates for micro-propagules to complete their life cycle and replenish the seed bank, thereby sustaining persistent YSGTs. It implied that habitat modification has pronounced ecological impacts on this intertidal muddy flat. The unique environmental conditions (enriched nutrients, esp. nitrate, favourable seawater temperatures in spring, and strong tidal mixing) facilitated the abundance, seasonal variation and recruitment of micro-propagules in the Subei Shoal. Given the current mitigation measures implemented in the raft region, further research is required to monitor and investigate the physiological and ecological responses of micro-propagule populations to the complex hydrobiological, geochemical, and physical matrices.

Lipid-lowering, antihypertensive, and antithrombotic effects of nattokinase combined with red yeast rice in patients with stable coronary artery disease: a randomized, double-blinded, placebo-controlled trial.

Nattokinase (NK) and red yeast rice (RYR) are both indicated for their potential in cardiovascular disease prevention and management, but their combined effects especially in coronary artery disease (CAD) are scarcely examined. This 90-day randomized, double-blind trial aims to investigate the effect of NK and RYR supplementations on cardiometabolic parameters in patients with stable CAD. 178 CAD patients were randomized to four groups: NK + RYR, NK, RYR, and placebo. No adverse effects due to the interventions were reported. In comparisons across groups, NK + RYR showed the maximum effect in reducing triglyceride (-0.39 mmol), total cholesterol (-0.66 mmol/L), diastolic blood pressure (-7.39 mmHg), and increase in high-density lipoprotein cholesterol (0.195 mmol/L) than other groups (all p for multiple groups comparison<0.01). Both NK + RYR and NK groups had significantly better-improved lactate dehydrogenase than the others (-29.1 U/L and - 26.4 U/L). NK + RYR group also showed more potent reductions in thromboxane B2 and increases in antithrombin III compared to placebo (both p < 0.01). These improved markers suggest that combined NK and RYR may preferably alter antithrombin and COX-1 pathways, potentially reducing thrombosis risks in CAD patients. Overall, the combined NK and RYR supplementation is safe and more effective than separately in improving cardiometabolic markers among CAD patients with multiple heart medications use.

Biomineralization in a cold environment: Insights from shield compositions and transcriptomics of polar sternaspids (Sternaspidae, Polychaeta).

The survival and physiological functions of polar marine organisms are impacted by global climate changes. Investigation of the adaptation mechanisms underlying biomineralization in polar organisms at low temperatures is important for understanding mineralized organismal sensitivity to climate change. Here, we performed electron probe analysis on the shields of Antarctic polychaete Sternaspis sendalli and Arctic polychaete Sternaspis buzhinskajae (Sternaspidae), and sequenced the transcriptomes of the tissues surrounding shields to examine biomineral characteristics and adaptive mechanisms in persistently cold environments. Compared to the temperate relative species, the relative abundance of iron, phosphorus, calcium, magnesium, nitrogen, sulfur and silicon in two polar sternaspid shields was similar to Sternaspis chinensis. However, the diversity and expression levels of biomineralization-related shell matrix proteins differed between the polar and temperate species, suggesting distinct molecular mechanisms underlying shield formation in cold environments. Tubulin and cyclophilin were upregulated compared to the temperate species. Furthermore, 42 positively selected genes were identified in Antarctic S. sendalli, with functions in cytoskeletal structure, DNA repair, immunity, transcription, translation, protein synthesis, and lipid metabolism. Highly expressed genes in both polar species were associated with cytoskeleton, macromolecular complexes and cellular component biosynthesis. Overall, this study reveals conserved elemental composition yet distinct biomineralization processes in the shields of polar sternaspids. The unique expression of biomineralization related genes and other cold-adaptation related genes provide molecular insights into biomineralization in cold marine environments.

Spatial-temporal shifting patterns and in situ conservation of spotted seal (Phoca largha) populations in the Yellow Sea ecoregion.

Understanding the habitat shifting pattern is a prerequisite for implementing in situ conservation of migratory species. Spotted seals (Phoca largha) inhabiting the Yellow Sea ecoregion (YSE) comprise a small population with independent genes and represent a charismatic flagship species in this region. However, this population has declined by 80% since the 1940s, and increased support from the countries around the YSE is urgently needed to address the potential local extinction risk. A time-series niche model and life-history weighted systematic conservation planning were designed on the basis of a satellite beacon tracking survey (2010-2020) of the YSE population. The results showed clustering and spreading shifting patterns during the breeding and migratory seasons, respectively. The closed-loop migration route formed in the YSE indicated that this population might be geographically isolated from populations in other breeding areas around the world. The conservation priority area (CPA), with an area of 19 632 km2 (3.58% of the total YSE area), was the most effective response to the potential in situ risk. However, nearly 80% of the CPA was exposed outside the existing marine protected areas (MPAs). Future establishment of MPAs in China should strategically consider the conservation gap identified herein, and it is recommended for Korea's closed fishing season to be spatially set in the western Korean Peninsula from May to August. This study also exemplified that the lack of temporal information would lead to the dislocation of niche modeling for migratory species represented by spotted seals. Attention should be paid to protecting small and migratory populations in marine biodiversity conservation planning.

Symbiotic relationship of Comaster schlegelii (Crinoidea: Comatulidae) And Gymnolophus obscura (Ophiuroidea: Ophiotrichidae) derived from stable isotope and fatty acid analyses.

Coral reef community exhibit high species diversity and a broad range of biological relationships including widespread symbiosis and complex food utilization patterns. In our study, we investigated the symbiotic relationship between the commonly crinoid host Comaster schlegelii and its ophiuroid obligatory symbiont Gymnolophus obscura. Using a combination of fatty acid biomarkers and stable isotopic compositions, we explored differences in their organic matter utilization strategies and nutritional relationships. The result of stable isotopes revealed that G. obscura had higher δ15N values than its crinoid host. Particulate organic matter and phytoplankton were identified as the primary food sources for both species, however C. schlegelii showed a higher proportional contribution from benthic microalgae. Fatty acid markers showed that C. schlegelii was more dependent on benthic microalgae such as diatoms, and less on debritic organic matter and bacteria than G. obscura. Elevated δ15N values of G. obscura and similar food source contribution rates between the host and symbiont suggest that ophiuroid feeds on materials filtered by crinoids and have similar diet to the host. Our results provide insights into the symbiotic patterns of crinoids and ophiuroids, while also supplying foundational data on how symbiotic reef species select organic matter utilization strategies to adapt to their environment.

Distinct gut microbial communities and functional predictions in divergent ophiuroid species: host differentiation, ecological niches, and adaptation to cold-water habitats.

IMPORTANCE: Gastrointestinal microorganisms are critical to the survival and adaptation of hosts, and there are few studies on the differences and functions of gastrointestinal microbes in widely distributed species. This study investigated the gut microbes of two ophiuroid species (Ophiura sarsii and its subspecies O. sarsii vadicola) in cold-water habitats of the Northern Pacific Ocean. The results showed that a combination of host and environmental factors shapes the intestinal microbiota of ophiuroids. There was a high similarity in microbial communities between the two groups living in different regions, which may be related to their similar ecological niches. These microorganisms played a vital role in the ecological success of ophiuroids as the foundation for their adaptation to cold-water environments. This study revealed the complex relationship between hosts and their gut microbes, providing insights into the role they play in the adaptation and survival of marine species.

Interannual variations of Sargassum blooms in the Yellow Sea and East China Sea during 2017-2021.

Golden tide, caused by Sargassum horneri, is becoming another periodic and trans-regional harmful macroalgal bloom in the Yellow Sea (YS) and East China Sea (ECS) other than the green tide. In this study, we employed high-resolution remote sensing, field validations, and population genetics to investigate the spatiotemporal development pattern of Sargassum blooms during the years 2017 to 2021 and explore the potential environmental factors that influence them. Sporadic floating Sargassum rafts could be detected in the middle or northern YS during autumn and the distribution area then occurred sequentially along the Chinese and/or western Korean coastlines. The floating biomass amplified significantly in early spring, reached its maximum in two to three months with an evident northward expansion, and then declined rapidly in May or June. The scale of the spring bloom was much larger than the winter one in terms of coverage, suggesting an additional local source in ECS. The blooms were mostly confined to waters with a sea surface temperature range of 10-16℃, while the drifting pathways were consistent with the prevailing wind trajectory and surface currents. The floating S. horneri populations exhibited a homogenous and conservative genetic structure among years. Our findings underscore the year-round cycle of golden tides, the impact of physical hydrological environments on the drifting and blooming of pelagic S. horneri, and provide insights for monitoring and forecasting this emerging marine ecological disaster.

Microstructure and Mechanical Properties of TA2/Q235 Laser Weld Joint with Copper Interlayer.

For the dissimilar metal welding needs of TA2 titanium and Q235 steel, preliminary trials were conducted using laser welding methods, and the results showed that the addition of a copper interlayer and the bias of the laser beam toward the Q235 side allowed for an effective connection. The welding temperature field was simulated using the finite element method, and the optimum offset distance of 0.3 mm was obtained. Under the optimized parameters, the joint had good metallurgical bonding. Further SEM analysis showed that the microstructure of the bonding area between the weld bead and Q235 was a typical fusion weld pattern, while that of the bonding area between the weld bead and TA2 was in brazing mode. The microhardness of the cross-section showed complex fluctuations; the microhardness of the weld bead center was higher than that of the base metal due to the formation of a mixture microstructure of copper and dendritic Fe phases. The copper layer not involved in the weld pool mixing had almost the lowest microhardness. The highest microhardness was found at the bonding site of TA2 and the weld bead, mainly due to the formation of an intermetallic layer with a thickness of about 100 µm. Further detailed analysis revealed that the compounds included Ti2Cu, TiCu and TiCu2, showing a typical peritectic morphology. The tensile strength of the joint was approximately 317.6 MPa, reaching 82.71% of that of the Q235 and 75.44% of the TA2 base metal, respectively. The fracture occurred in the unmixed copper layer.

Blidingia sp. extracts improve intestinal health and reduce diarrhoea in weanling piglets.

Blidingia sp. is a prominent fouling green macroalga and we previously found that extracts from Blidingia sp. alleviated intestinal inflammation in mice challenged with lipopolysaccharides. However, whether these extracts are effective in weanling piglets remains unknown. In the present study, Blidingia sp. extracts were supplemented in the diet and their effects on growth performance, incidence of diarrhoea and intestinal function in weanling piglets were explored. The results showed that diets supplemented with 0.1% or 0.5% Blidingia sp. extract significantly increased average daily body weight gain and feed intake in weanling piglets. Meanwhile, piglets supplemented with 0.5% Blidingia sp. extract showed decreased incidence of diarrhoea as well as reduced fecal water and Na+ content. Furthermore, the diet supplemented with 0.5% Blidingia sp. extracts improved intestinal morphology, as indicated by the results of hematoxylin and eosin staining. Diet supplemented with 0.5% Blidingia sp. extracts also improved tight junction function, as indicated by increased expression of Occludin, Claudin-1 and Zonula occludens-1, and alleviated the inflammatory response, as indicated by decreased tumor necrosis factor-α and interleukin-6 (IL6) contents and increased IL10 levels. Taken together, our results showed that Blidingia sp. extracts had beneficial effects in weanling piglets and we suggest that Blidingia sp. extracts could be potentially used as an additive for piglets.

The drifting and spreading mechanism of floating Ulva mass in the waterways of Subei shoal, the Yellow Sea of China - Application for abating the world's largest green tides.

The large-scale green tides have been prevailing in the Yellow Sea over a decade. Prevention and control techniques in the source region (Subei Shoal) are urgently needed to minimize its adverse ecological and social impacts. Drifting and spreading mechanism of Ulva mass was investigated in the Subei Shoal in order to develop the early containment measures. The multidisciplinary surveys suggested twelve major waterways transporting the initial Ulva mass which was closely related to the basin topology and water circulation in the shoal. The epiphytic algal mass from the northern and eastern raft regions contributed 82.7 % of the initial floating biomass, and moved out in 4-6 days with an average drifting velocity of 0.28 m s-1. Accordingly, two series of algae-blocking lines were proposed to remove floating mass from the shoal. And the primary field trial in 2018 confirmed the feasibility of this strategy to abate the green tides.

Spatiotemporal Dynamics of Coastal Viral Community Structure and Potential Biogeochemical Roles Affected by an Ulva prolifera Green Tide.

The world's largest macroalgal green tide, caused by Ulva prolifera, has resulted in serious consequences for coastal waters of the Yellow Sea, China. Although viruses are considered to be one of the key factors in controlling microalgal bloom demise, understanding of the relationship between viral communities and the macroalgal green tide is still poor. Here, a Qingdao coastal virome (QDCV) time-series data set was constructed based on the metagenomic analysis of 17 DNA viromes along three coastal stations of the Yellow Sea, covering different stages of the green tide from Julian days 165 to 271. A total of 40,076 viral contigs were detected and clustered into 28,058 viral operational taxonomic units (vOTUs). About 84% of the vOTUs could not be classified, and 62% separated from vOTUs in other ecosystems. Green tides significantly influenced the spatiotemporal dynamics of the viral community structure, diversity, and potential functions. For the classified vOTUs, the relative abundance of Pelagibacter phages declined with the arrival of the bloom and rebounded after the bloom, while Synechococcus and Roseobacter phages increased, although with a time lag from the peak of their hosts. More than 80% of the vOTUs reached peaks in abundance at different specific stages, and the viral peaks were correlated with specific hosts at different stages of the green tide. Most of the viral auxiliary metabolic genes (AMGs) were associated with carbon and sulfur metabolism and showed spatiotemporal dynamics relating to the degradation of the large amount of organic matter released by the green tide. IMPORTANCE To the best of our knowledge, this study is the first to investigate the responses of viruses to the world's largest macroalgal green tide. It revealed the spatiotemporal dynamics of the unique viral assemblages and auxiliary metabolic genes (AMGs) following the variation and degradation of Ulva prolifera. These findings demonstrate a tight coupling between viral assemblages, and prokaryotic and eukaryotic abundances were influenced by the green tide.

Identification of Potential Differentially-Methylated/Expressed Genes in Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease that causes obstructed airflow from the lungs. DNA methylation can regulate gene expression. Understanding the potential molecular mechanism of COPD is of great importance. The aim of this study was to find differentially methylated/expressed genes in COPD. DNA methylation and gene expression profiles in COPD were downloaded from the dataset, followed by functional analysis of differentially-methylated/expressed genes. The potential diagnostic value of these differentially-methylated/expressed genes was determined by receiver operating characteristic (ROC) analysis. Expression validation of differentially-methylated/expressed genes was performed by in vitro experiment and extra online datasets. Totally, 81 hypermethylated-low expression genes and 121 hypomethylated-high expression genes were found in COPD. Among which, 9 core hypermethylated-low expression genes (CD247, CCR7, CD5, IKZF1, SLAMF1, IL2RB, CD3E, CD7 and IL7R) and 8 core hypomethylated-high expression genes (TREM1, AQP9, CD300LF, CLEC12A, NOD2, IRAK3, NLRP3 and LYZ) were identified in the protein-protein interaction (PPI) network. Moreover, these genes had a potential diagnostic utility for COPD. Some signaling pathways were identified in COPD, including T cell receptor signaling pathway, cytokine-cytokine receptor interaction, hematopoietic cell lineage, HTLV-I infection, endocytosis and Jak-STAT signaling pathway. In conclusion, differentially-methylated/expressed genes and involved signaling pathways are likely to be associated with the process of COPD.

Identification of candidate aberrant differentially methylated/expressed genes in asthma.

BACKGROUND: Asthma is an important non-communicable disease worldwide. DNA methylation is associated with the occurrence and development of asthma. We are aimed at assuring differential expressed genes (DEGs) modified by aberrantly methylated genes (DMGs) and pathways related to asthma by integrating bioinformatics analysis. METHODS: One mRNA dataset (GSE64913) and one gene methylation dataset (GSE137716) were selected from the Gene Expression Omnibus (GEO) database. Functional enrichment analysis was performed using GeneCodies 4.0 database. All gene expression matrices were analyzed by Gene set enrichment analysis (GSEA) software. STRING was applied to construct a protein-protein interaction (PPI) network to find the hub genes. Then, electronic validation was performed to verify the hub genes, followed by the evaluation of diagnostic value. Eventually, quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to detect the expression of hub genes. RESULTS: In total, 14 hypomethylated/high-expression genes and 10 hypermethylated/low-expression genes were obtained in asthma. Among them, 10 hub genes were identified in the PPI network. Functional analysis demonstrated that the differentially methylated/expressed genes were primarily associated with the lung development, cytosol and protein binding. Notably, HLA-DOA was enriched in asthma. FKBP5, WNT5A, TM4SF1, PDK4, EPAS1 and GMPR had potential diagnostic value for asthma. CONCLUSION: The project explored the pathogenesis of asthma, which may provide a research basis for the prediction and the drug development of asthma.

Ulva prolifera Polysaccharide-Manganese Alleviates Inflammation and Regulates Microbiota Composition in Dextran Sulfate Sodium-Induced Colitis Mice.

Manganese (Mn) deficiency exacerbates colitis symptoms, whereas diet supplemented with inorganic Mn merely maintains colon length in experimental colitis. In the present study, a new form of Mn, Ulva prolifera polysaccharide cheated-Mn (PMn) was used and its treatment effects on dextran sulfate sodium (DSS)-induced colitis were investigated. Male C57BL/6 mice were orally administrated with 3.5% DSS to induce colitis. Then, the colitis mice were treated with PBS or PMn for 7 days. The results showed that PMn administration help retrieve the body weight loss and intestinal morphology damage, and alleviate apoptosis and inflammatory responses in colitis mice. Moreover, PMn administration decreased intestinal infiltration as indicated by decreased concentration of myeloperoxidase and eosinophil peroxidase. Importantly, PMn retrieved the increased abundance of Firmicutes and the decreased abundance of Bacteroidetes caused by DSS, suggested its beneficial roles in regulating microbiota composition in mice with colon inflammation. Gut microbiota composition at the genus level in the mice administrated with PMn was similar to those in control mice, whereas they were clearly distinct from DSS-treated mice. These results support the potential therapeutic role of PMn in the treatment of intestinal colitis and microbes may play critical roles in mediating its effects.

Bioaccumulation of mercury along continuous fauna trophic levels in the Yellow River Estuary and adjacent sea indicated by nitrogen stable isotopes.

Mercury (Hg), and its organic forms, are some of the most hazardous elements, with strong toxicity, persistence, and biological accumulation in marine organisms. Hg accumulation in continuous trophic levels (TL) in marine food chains remains unclear. In this study, individual invertebrate and fish samples collected from the Yellow River Estuary adjacent sea were grouped into continuous TL ranges, and the bioaccumulations of total Hg (THg) and methylmercury (MeHg) were analyzed. The trophic magnification factor in invertebrates and fish was 1.40 and 1.72 for THg, and 2.56 and 2.17 for MeHg, indicating that both THg and MeHg were significantly biomagnified with increasing TL in both invertebrates and fish through trophic transfer. To evaluate the health risk of seafood consumption, the target hazard quotient (THQ) was calculated. Increasing THQ values indicated that the health risks of invertebrate and fish consumption in humans, especially children, were both elevated with increasing TL. THQ values > 1 indicated that consumption of invertebrates at a TL above 4.0 and fish above 4.5 may pose a relatively higher risk for children. Therefore, the consumption of both individual invertebrates and fish at high trophic positions may present greater health risk, especially in young children.

Corrigendum: Assessing Herbivorous Impacts of Apohyale sp. on the Ulva prolifera Green Tide in China.

[This corrects the article DOI: 10.3389/fpls.2021.795560.].

Factors influencing the spatial and temporal distributions of green algae micro-propagules in the coastal waters of Jinmenghaiwan, Qinhuangdao, China.

Since 2015, green tides have impacted the coastal waters of Qinhuangdao, particularly at Jinmenghaiwan bath. Micro-propagules are considered the "seed bank" of algal blooms and play an important role in the formation of green tides. To investigate the spatial and temporal distributions of micro-propagules of green algae and associated environmental factors, a field survey was carried out in the coastal waters of Jinmenghaiwan, Qinhuangdao, China. The results showed that the NO3-N concentration was the most important impact factor of the abundance of micro-propagules and explained 42.9% of the total variance. Furthermore, the number of micro-propagules was significantly and positively correlated with the biomass of attached and floating macroalgae. Therefore, reducing the NO3-N concentration by controlling the NO3-N input from Tang River is expected to be an effective measure to prevent and control green tides in the coastal waters of Qinhuangdao.

A new assessment of the algal biomass of green tide in the Yellow Sea.

The annually recurring Yellow Sea green tide causes significant economic, social, and ecological impacts in China. Currently, the magnitude of Yellow Sea green tide is usually evaluated according to the snap shot maximum algal coverage area or artificially removed algal biomass. However, this method ignores growth of the alga Ulva prolifera and thus needs improvement. We build a model to predict algal growth in drifting from upstream and the potential muaximum biomass of green tide. The results suggest that the potential maximum biomass is significantly higher than those estimated merely from maximum algal coverage area, particularly for years with extended period of algal loading in the upstream. Our method improves the evaluation of the magnitude of green tide and provides a scientific basis for developing effective countermeasures to reduce the persistent disaster.

Harmful macroalgal blooms (HMBs) in China's coastal water: Green and golden tides.

Harmful macroalgal blooms (HMBs) have been increasing along China's coasts, causing significant social impacts and economic losses. Besides extensive eutrophication sustaining coastal seaweed tides, the stimuli and dynamics of macroalgal blooms in China are quite complex and require comprehensive studies. This review summarizes the distinct genesis, development and drifting patterns of three HMBs that have persistently occurred in China's coastal waters during recent years: transregional green tides of drifting Ulva prolifera in the Yellow Sea (YS), local green tides of multiple suspended seaweeds in the Bohai Sea and large-scale golden tides of pelagic Sargassum horneri in the YS and East China Sea. While specific containment measures have been developed and implemented to effectively suppress large-scale green tides in the YS, the origin and blooming mechanism of golden tides remain unclear due to lack of field research. With the broad occurrence of HMBs and their increased accumulation on beaches and coastal waters, it is necessary to investigate the blooming mechanism and ecological impacts of these HMBs, especially with the growing stresses of climate change and anthropogenic disturbances.