Seaweeds are some of the largest producers of biomass in the marine environment and are rich in bioactive compounds that are often used for human and animal health. Porphyran and carrageenan are ...natural compounds derived from red seaweeds. The former is a characteristic polysaccharide of
, while the latter is well known from
,
, and various
species, all in Rhodophyceae. The two polysaccharides have been found to have anti-cancer activity by improving immunity and targeting key apoptotic molecules and therefore deemed as potential chemotherapeutic or chemopreventive agents. This review attempts to review the current study of anti-cancer activity and the possible mechanisms of porphyran and carrageenan derived from red seaweeds to various cancers, and their cooperative actions with other anti-cancer chemotherapeutic agents is also discussed.
In this study, traditional culture-based techniques and the 16S rDNA sequencing method were used to investigate the microbial community of the intestinal contents and mucosal layer in the intestine ...of yellow catfish (
Pelteobagrus fulvidraco). Eleven phylotypes were detected from culturable microbiota, and their closest relatives were
Plesiomonas,
Yersinia,
Enterobacter,
Shewanella,
Aeromonas,
Vibrio, and
Myroides. Forty-four phylotypes were retrieved from 100 positive clones from intestinal contents (library C), and 21 phylotypes were detected in the 57 positive clones from intestinal mucus (library M), most of which were affiliated with Proteobacteria (>
50% of the total). However, the bacterial groups OP10 and Actinobacteria detected in library C were not found in library M, suggesting that the abundance and diversity of bacterial populations in mucus might be different from the microbiota in gut contents, and that some microbial species poorly colonized the gut mucosal layer.
Cyanobacterial blooms aggravate with increasing temperature, and the increased concentrations of toxicants such as cyanotoxins and nitrite during bloom decay adversely affect the growth of aquatic ...animals. Heat-shock proteins (Hsps) are induced by a wide range of environmental stressors, including temperature and toxicants. In this study,
Brachionus calyciflorus
Pallas was exposed to different combined solutions of microcystin-LR (0, 10, 30, and 100 µg L
−1
) and nitrite (0, 1, 3, and 5 mg L
−1
) to evaluate their effects on the rotifer lifespan, the reproductive rate (
R
), and the responses of four Hsp genes at 20 °C, 25 °C, and 30 °C. Results revealed that single high doses of microcystin-LR (100 µg L
−1
) and nitrite (5 mg L
−1
) were harmful to the lifespan and reproduction of rotifers. Hormesis was induced by low doses of microcystin-LR (10–30 µg L
−1
) and nitrite (1–3 mg L
−1
). At different toxicant concentrations, the expression levels of
Hsp40
,
Hsp60
,
Hsp70
, and
Hsp90
fluctuated, whereas reactive oxygen species (ROS) levels increased regardless of temperature. The two toxicants induced high levels of ROS production, which negatively affected the lifespan,
R
, and Hsp gene expression at 30 °C (
p
< 0.05). Microcystin-LR and nitrite exerted synergistic effects on the lifespan,
R
, ROS levels, and Hsp gene expression levels at 20 °C and 25 °C (
p
< 0.05) but had antagonistic effects on
Hsp40
and
Hsp60
expression levels at 30 °C (
p
> 0.05). Temperature, microcystin-LR, and nitrite had interactive effects on the lifespan,
R
, ROS levels, and Hsp gene expression levels (
p
< 0.05). The expression levels of Hsp genes are useful biomarkers of high-temperature exposure, and
Hsp
-mediated heat shock responses are important in microcystin-LR and nitrite stress tolerance of
B. calyciflorus
.
Freshwater salinization is a growing environmental issue caused by various anthropic or natural factors that lead to changes in water chemistry and physical conditions, affecting the survival and ...diversity of phytoplankton. In this study, we tested the physiological, morphological and interspecific competition of the freshwater cyanobacterium Microcystis aeruginosa and the green algae Scenedesmus obliquus to salinity stress. Results demonstrated that increasing salinity had a significant negative effect on the growth of M. aeruginosa and S. obliquus. M. aeruginosa showed a decline in growth rate with increasing salinity, while S. obliquus showed a lower growth rate under salinity stress but with no significant difference between the two salinity groups. In cocultures, S. obliquus outcompeted M. aeruginosa, and the displacement was accelerated with increasing salinity. The photosynthetic performance of both algae was affected by salinity, the presence of competitors, and the cultivation time. S. obliquus showed morphological variations under salinity stress and the presence of a competitor. The study suggests that salinity stress and competition can have a significant impact on the growth and performance of algae species. The findings of our study suggest that the salinization of freshwater can impact the interspecific interactions among phytoplankton, which play a crucial role in the functioning of freshwater ecosystems.
This study used berberine hydrochloride to treat the Asian paddle crab, Charybdis japonica infected with the Gram-negative bacterium Aeromonas hydrophila at concentrations of 0, 100, 200 and 300 ...mg/L. The effect of berberine hydrochloride on the survival rate and gut microbiota of C. japonica was investigated. Berberine hydrochloride improved the stability of the intestinal flora, with an increase in the abundance of probiotic species and a decrease in the abundance of both pathogenic bacteria after treatment with high concentrations of berberine hydrochloride. Berberine hydrochloride altered peroxidase activity (POD), malondialdehyde (MDA), and lipid peroxidation (LPO) in the intestinal tract compared to the control. Berberine hydrochloride could modulate the energy released from the enzyme activities of hexokinase (HK), phosphofructokinase (PFK), and pyruvate kinase (PK) in the intestinal tract of C. japonica infected with A. hydrophila. Zona occludens 1 (ZO-1), Zinc finger E-box binding homeobox 1 (ZEB1), occludin and signal transducer, and activator of transcription5b (STAT5b) expression were also increased, which improved intestinal barrier function. The results of this study provide new insights into the role of berberine hydrochloride in intestinal immune mechanisms and oxidative stress in crustaceans.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Nitrite is one of the most common pollutants in high-density aquaculture or in recirculated aquaculture systems. In this study, gene and miRNA expression dynamics were investigated for unveiling the ...genetic regulation of
Eriocheir sinensis
in response to acute nitrite stress. Two groups of
E. sinensis
with different vitality of appendages (i.e., NG and DG) were treated with nitrite-N in 6 and 24 h, respectively. A number of differentially expressed (DE) genes and miRNAs were detected in the pairwise comparisons of the two groups. We found that the DE genes and the target genes of DE miRNAs were significantly enriched into some key pathways, such as metabolic pathways, MAPK signaling pathway, and nitrogen metabolism. Notably, the number of DE genes identified from the pairwise comparison of MNG vs. FNG (NG groups at 6 h and 12 h, respectively) was much larger than that identified from MDG vs. FDG (FG groups at 6 h and 12 h, respectively), indicating that the individuals from strong vitality group had genetic superiority for tolerance of nitrite stress. The similar trend was also observed from the identification of DE miRNAs. Some key genes (e.g.,
hsp70
,
mtnd2
,
act7
,
hspg2
,
cam-1
) involved in signaling transduction, oxidative phosphorylation, and energy metabolism were detected in this study. Besides, several miRNAs (miR-31, miR-215, miR-142-x) that mediate the calmodulin related genes were also identified, inferring that calcium signaling pathway participates in the responses to nitrite stress in crabs. This study revealed the mRNA and miRNA expression patterns of Chinese mitten crab under sustained nitrite stress and provided the genetic basis for the molecular selective breeding.
Biological migration is usually associated with disturbances and environmental changes that are key drivers in determining the diversity, community compositions, and function of gut microbiome. ...However, little is known about how gut microbiome is affected by disturbance such as salinity changes during migration from seawater to freshwater. Here, we tracked the gut microbiome succession of Chinese mitten crabs (
) during their migrations from seawater to freshwater and afterward using 16S rDNA sequencing for 127 days, and explored the temporal patterns in microbial diversity and the underlying environmental factors. The species richness of gut microbiome showed a hump-shaped trend over time during seawater-freshwater migration. The community dissimilarities of gut microbiome increased significantly with day change. The turnover rate of gut microbiome community was higher during seawater-freshwater transition (1-5 days) than that in later freshwater conditions. Salinity was the major factor leading to the alpha diversity and community dissimilarity of gut microbiome during seawater-freshwater transition, while the host selection showed dominant effects during freshwater stage. The transitivity, connectivity, and average clustering coefficient of gut microbial co-occurrence networks showed decreased trends, while modularity increased during seawater-freshwater migration. For metabolic pathways, "Amino Acid Metabolism" and "Lipid Metabolism" were higher during seawater-freshwater transition than in freshwater. This study advances our mechanistic understanding of the assembly and succession of gut microbiota, which provides new insights into the gut ecology of other aquatic animals.
Gene duplication (GD) leads to the expansion of gene families that contributes organisms adapting to stress or environment and dealing with the infection of various pathogens. C-type lectins (CTLs) ...in crustaceans undergo gene expansion and participate in various immune responses. However, the functions of different CTL produced by GD are not fully characterized. In the present study, two CTL genes (designated as
and
, respectively) were identified from
.
and
originate from GD and the main difference between them is exon 3. PcLec-EPS and PcLec-QPS respectively contains EPS and QPS motif in their carbohydrate recognition domain. The mRNA levels of
and
in hemocytes, gills, intestine and lymph underwent time-dependent enhancement after D-Mannose and D-Galactose challenge. Recombinant PcLec-EPS and PcLec-QPS could bind to carbohydrates and microbes, and agglutinate bacteria. The results of experiments on recombinant protein injection and RNA interference indicate that PcLec-EPS and PcLec-QPS can respectively strong recognize and bind D-Mannose and D-Galactose, activate the Relish transcriptional factor, and further upregulate the expression of different antimicrobial peptides (AMPs). In addition, these two CTLs and Relish could positively regulate the expression of each other, suggesting that there is a positive feedback loop between two CTLs and Relish that regulates the expression of AMPs. It may contribute to the expansion of the immune response for host quickly and efficiently eliminating pathogenic microorganisms. This study provides new knowledge for clear understanding the significance and function of different CTL generated by GD in immune defenses in crustacean.
The interaction between nutrients, heavy metals, and sediment bacterial communities play a key role in the health of crabs and the biogeochemical cycles of aquaculture systems. However, the effects ...of sediment improvement activities in crab culture on nutrients and heavy metals and the response of bacterial communities to the relevant changes are unclear. In this study, 24 water and sediment samples were collected from two aquaculture sites (total of 12 ponds, 6 at each site). High-throughput sequencing was used to determine the structure of the bacterial community and the diversity in water and sediment samples. The relationship between nutrients, heavy metals, and bacterial communities and the changes of the three before and after the improvement of the sediment were analyzed. The results showed that Proteobacteria, Bacteroidetes, Acidobacteria, Chloroflexi, and Firmicutes were predominant at the phylum level of sediment. Sediment improvement has an effect on NH4+-N, sulfide, total organic carbon (TOC), and heavy metals in sediments to varying degrees. In addition, redundancy analysis found that NH4+-N, NO3−-N, TP, and heavy metals were key drivers in crab culture pond sediments. The results of functional prediction showed that carbon, nitrogen, and sulfur metabolism were the dominant processes in the two crab farming areas. Overall, changes in nutrients and heavy metals caused by sediment improvement further affected the structure and function of bacterial communities and may affect biogeochemical cycles. Our study has deepened the understanding of the effects of sediment improvement on nutrients, heavy metals, and bacterial communities in crab culture ponds.
As an enduring Chinese freshwater aquaculture product, the
has a high economic value and is characterized by a catadromous life style that undergoes seawater-freshwater migration. However, little is ...known about their gut microbial status as they move from saltwater to freshwater acclimatization. Here, we sampled and cultivated
megalopa from three aquaculture desalination ponds and investigated their gut microbiota diversity, community structures and biotic interactions from megalopa stage to the first juvenile stage after desalination for 9 days. Our results revealed that during the transition from megalopa to the first juvenile in
, a significant change in gut microbial composition was observed (for instance, changes in relative abundance of dominant phyla), which was, however, not influenced by different sampling sites. The species diversity (such as the richness) of the gut microbiota showed a hump-shaped pattern along the succession. However, the compositional differences of the gut microbes showed constantly increasing patterns during the succession after freshwater adaption for all three sampling sites. Further co-occurrence analysis also showed that the complexity of the ecological networks in gut microbes was significantly enhanced during the development, such as increasing numbers of network links, connectivity and modularity, and was confirmed by decreasing average path length and proportions of negative links. Taken together, the differences in community structures and biological interactions of gut microorganisms were more pronounced in
megalopa during desalination than in diversity and species compositions. This implies that the gut microbes of
megalopa would become more robust and adaptive during the developmental process.
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