Process and mechanism of termite impact on soil and plant.

Termites, as a kind of nesting social insects, are often confused as worldwide "pests" because some of their groups have great destructive effects. The vast majority of termites can regulate ecosystem functions and ser-vices by participating in biogeochemical cycles, known as "ecosystem engineers". We reviewed studies on the effects of termites on the physical, chemical and biological characteristics of mound soil ecosystems and the composition and diversity of plant communities. Termites could form unique soil "biogenic aggregates" and "resource heterogeneity patches", which affect microbial community structure, extracellular enzyme activity, physicochemical property and greenhouse gas emission, thereby affecting plant growth, community composition and structure, and vegetation productivity. However, this effect significantly differed among termite groups and functional groups, and was dependent on regional soil environment and microclimate conditions. Meanwhile, termite-mound could effectively improve ecosystem adaptation or resistance to environmental stress through the above process. Future research should focus on the following directions: 1) studying the trophic cascading effect of termite-centered soil multilevel biological network and the potential effect on biogeochemical cycle from microscale (aggregate level) to macroscale (landscape level); 2) exploring the potential of termite mound soil as a fertility amendment in tropical regions, and mining beneficial microbial functional genes to develop related products for termite control.

A(H2N2) and A(H3N2) influenza pandemics elicited durable cross-reactive and protective antibodies against avian N2 neuraminidases.

Human cases of avian influenza virus (AIV) infections are associated with an age-specific disease burden. As the influenza virus N2 neuraminidase (NA) gene was introduced from avian sources during the 1957 pandemic, we investigate the reactivity of N2 antibodies against A(H9N2) AIVs. Serosurvey of healthy individuals reveal the highest rates of AIV N2 antibodies in individuals aged ≥65 years. Exposure to the 1968 pandemic N2, but not recent N2, protected against A(H9N2) AIV challenge in female mice. In some older adults, infection with contemporary A(H3N2) virus could recall cross-reactive AIV NA antibodies, showing discernable human- or avian-NA type reactivity. Individuals born before 1957 have higher anti-AIV N2 titers compared to those born between 1957 and 1968. The anti-AIV N2 antibodies titers correlate with antibody titers to the 1957 N2, suggesting that exposure to the A(H2N2) virus contribute to this reactivity. These findings underscore the critical role of neuraminidase immunity in zoonotic and pandemic influenza risk assessment.

Novel therapeutic activities of dragon blood from palm tree Daemonorops draco for the treatment of chronic diabetic wounds.

BACKGROUND: The clinical efficacy of Jinchuang Ointment, a traditional Chinese medicine (TCM), in treating chronic non-healing diabetic wounds has been demonstrated over the past decades. Both in vitro and in vivo angiogenic activities have been reported for its herbal ingredients, including dragon blood from the palm tree Daemonorops draco and catechu from Uncaria gambir Roxb. Additionally, crude extracts of dragon blood have exhibited hypoglycemic effects not only in animal studies but also in cell-based in vitro assays. RESULTS: Our findings indicate that crude dragon blood extract promotes the differentiation of myoblasts into myotubes. Partially purified fractions of dragon blood crude extract significantly enhance the expression of muscle cell differentiation-related genes such as myoG, myoD, and myoHC. Our results also demonstrate that crude extracts of dragon blood can inhibit platelet-derived growth factor-induced PAI-1 expression in primary rat vascular smooth muscle cells, thereby favoring changes in hemostasis towards fibrinolysis. Consistent with previous reports, reduced expression of plasminogen activator inhibitor 1 (PAI-1) accelerates wound healing. However, further separation resulted in a significant loss of both activities, indicating the involvement of more than one compound in these processes. Stem cells play a crucial role in muscle injury repair. Neither dragon blood nor catechu alone stimulated the proliferation of human telomerase reverse transcriptase (hTERT)-immortalized and umbilical cord mesenchymal stem cells. Interestingly, the proliferation of both types of stem cells was observed when crude extracts of dragon blood and catechu were present together in the stem cell growth medium. CONCLUSIONS: Dragon blood from D. draco offers multifaceted therapeutic benefits for treating chronic nonhealing diabetic wounds from various perspectives. Most drugs in Western medicine consist of small molecules with defined ingredients. However, this is not the case in TCM, as the activities of dragon blood reported in this study. Surprisingly, the activities documented here align with descriptions in ancient Chinese medical texts dating back to A.D. 1625.

Enhancing Pd Catalytic Activity by Amine Group Modification for Efficient Direct Synthesis of H2O2.

A great deal of research has been carried out on the design of Pd-based catalysts in the direct synthesis of H2O2, mainly for the purpose of improving the H2O2 selectivity by weakening the activation energy on the Pd active site and thus inhibiting the dissociation of the O-O bonds in O2*, OOH*, and HOOH*. However, this often results in insufficient activation energy for the reaction between H2 and O2 on Pd, leading to difficulties in improving both the selectivity and productivity of H2O2 simultaneously. Based on this, this study reports an efficient catalyst composed of amine-functionalized SBA-15-supported Pd. The strong metal-support interaction not only makes the PdNPs highly dispersed with more Pd active sites but also improves the stability of the catalyst. The amine group modification increases the proportion of Pd0, further enhancing Pd activity and promoting the adsorption and conversion of H2 and O2 on Pd, thereby significantly increasing H2O2 productivity. Additionally, the density-functional theory simulation results showed that due to the hydrogen-bonding force between the amine group and H2O2, this particular anchoring effect would make the hydrogenation and decomposition of H2O2 effectively suppressed. Ultimately, both the selectivity and productivity of H2O2 are improved simultaneously.

Hypoglycemic effects of dracorhodin and dragon blood crude extract from Daemonorops draco.

BACKGROUND: Dragon blood is a red fruit resin from the palm tree Daemonorops draco and is a herbal ingredient used in the traditional Chinese medicine, "Jinchuang Ointment," which is used to treat non-healing diabetic wounds. According to the Taiwan Herbal Pharmacopeia, the dracorhodin content in dragon blood should exceed 1.0%. RESULTS: Our findings indicate that dracorhodin and dragon blood crude extracts can stimulate glucose uptake in mouse muscle cells (C2C12) and primary rat aortic smooth muscle cells (RSMC). Dracorhodin is not the only active compound in dragon blood crude extracts from D. draco. Next, we orally administered crude dragon blood extracts to male B6 mice. The experimental group displayed a decreasing trend in fasting blood glucose levels from the second to tenth week. In summary, crude extracts of dragon blood from D. draco demonstrated in vivo hypoglycemic effects in B6 male mice. CONCLUSIONS: We provide a scientific basis "Jinchuang ointment" in treating non-healing wounds in patients with diabetes.

Regulatory mechanism of perinatal nonylphenol exposure on cardiac mitochondrial autophagy and the PINK1/Parkin signaling pathway in male offspring rats.

OBJECTIVE: This study investigated whether perinatal exposure to nonylphenol (NP) induces mitochondrial autophagy (i.e., mitophagy) damage in neonatal rat cardiomyocytes (NRCMs) and whether the PINK1/Parkin signaling pathway is involved in NP-induced primary cardiomyocyte injury. METHODS AND RESULTS: In vivo: Perinatal NP exposure increased apoptosis and mitochondrial damage in NRCMs. Mitochondrial swelling and autophagosome-like structures with multiple concentric membranes were observed in the 100 mg/kg NP group, with an increase in the number of autophagosomes. Disorganized fiber arrangement and elevated serum myocardial enzyme levels were observed with increasing NP dosage. Additionally, NP exposure led to increased MDA levels and decreased SOD activity and ATP levels in myocardial tissue. The mRNA expression levels of autophagy-related genes, including Beclin-1, p62, and LC3B, as well as the expression of mitochondrial autophagy-related proteins (PINK1, p-Parkin, Parkin, Beclin-1, p62, LC3-I, LC3-II, and LC3-II/I) and apoptosis-related proteins (Bax and caspase-3), increased, whereas the expression levels of the mitochondrial membrane protein TOMM20 and the anti-apoptotic protein Bcl-2 decreased. In vitro: NP increased ROS levels, LDH release, and decreased ATP levels in NRCMs. CsA treatment significantly inhibited the expression of autophagy-related proteins (Beclin-1, LC3-II/I, and p62) and apoptosis-related proteins (caspase-3 and Bax), increased the expression levels of TOMM20 and Bcl-2 proteins, increased cellular ATP levels, and inhibited LDH release. The inhibition of the PINK1/Parkin signaling pathway suppressed the expression of mitochondrial autophagy-related proteins (PINK1, p-Parkin, Parkin, Beclin-1, LC3-II/I, and p62) and apoptosis-related proteins (caspase-3 and Bax), increased TOMM20 and Bcl-2 protein expression, increased ATP levels, and decreased LDH levels in NRCMs. CONCLUSIONS: This study is novel in reporting that perinatal NP exposure induced myocardial injury in male neonatal rats, thereby inducing mitophagy. The PINK1/Parkin signaling pathway was involved in this injury by regulating mitophagy.

Cellular localization and potential ligands of a novel scavenger receptor class B/CD36 protein homolog (Pt-SRB2) identified in the marine crab, Portunustrituberculatus.

The scavenger receptor class B family proteins (SRB) are multiligand membrane receptor proteins. Herein, a novel SRB homolog (Pt-SRB2) was identified in Portunus trituberculatus. The open reading frame of Pt-SRB2 was predicted to encode 520 amino acid residues comprising a typical CD36 domain. Phylogenetic analysis showed that Pt-SRB2 distinctly clustered with the SRB homologs of most crustaceans and Drosophila but was separate from all vertebrate CD36/SRB. Semi-quantitative and Real-time quantitative PCR revealed that the abundance of Pt-SRB2 transcripts was the highest in hepatopancreas than in other tested tissues. Overexpressed Pt-SRB2 was distributed primarily in the cell membrane and cytoplasm of HEK293T or Drosophila Schneider 2 cells. In crab hemocytes, Pt-SRB2 was distributed primarily in the cell membrane by immunofluorescence staining. In addition, the immunofluorescence staining showed that green fluorescence signals were mainly located in the inner lumen membrane of the hepatopancreatic tubules. Moreover, solid-phase enzyme-linked immunosorbent assay revealed that rPt-SRB2-L exhibited relative high affinity with lipopolysaccharides, and relative moderate binding affinity with lipoteichoic acid or peptidoglycan. Of note, rPt-SRB2-L showed high binding affinity with eicosapentaenoic acid among a series of long-chain polyunsaturated fatty acids. Taken together, this study provided valuable data for understanding the functions of the crab CD36/SRB.

Land use change alters carbon and nitrogen dynamics mediated by fungal functional guilds within soil aggregates.

Land use change is one of the greatest threats to soil biodiversity and ecological functions; however, how such a transition affects soil carbon (C) and nitrogen (N) dynamics driven by fungal communities at the aggregate level remains unclear. Here, we explored the variation in soil C and N pools, specific enzyme activities and fungal communities and functional guilds within three aggregate sizes (megaaggregates, > 2 mm; macroaggregates, 0.25-2 mm; microaggregates, < 0.25 mm) in a natural forest, 12- and 24-year-old rubber monocultures and corresponding agroforestry systems in tropical China. Tropical forest conversion to rubber monocultures generally reduced C and N pools in all aggregates, while agroforestry systems decreased microbial biomass C and N. Carbon- and N-degrading enzyme activities responded differently to forest conversion and were enhanced in agroforestry systems. The levels of C and N pools and their related enzyme activities increased as the aggregate size decreased. Moreover, fungal compositional shifts in dominance from copiotrophic Ascomycota and Basidiomycota (r-strategists) into oligotrophic Zygomycota (K-strategists) were noted following forest conversion, resulting in more pathogenic fungi at the expense of saprotrophic and arbuscular mycorrhizal fungi. Pathogenic fungi were greatly inhibited due to abundant Mortierella after the establishment of 12-year-old agroforestry systems. The diversity of saprotrophic fungi was the highest in microaggregates. Regardless of land use type, aggregate-associated C and N pools, especially DOC, MBC, NO3--N and DON in microaggregates, were interactively mediated by functional guilds of fungi, which was primarily driven by soil pH. These results highlight the importance of fungal functional guilds in determining C and N dynamics at the aggregate level and provide insights into the sustainable management of cash tree plantations.

The impact of pre-existing influenza antibodies and inflammatory status on the influenza vaccine responses in older adults.

Age-associated immune changes and pre-existing influenza immunity are hypothesized to reduce influenza vaccine effectiveness in older adults, although the contribution of each factor is unknown. Here, we constructed influenza-specific IgG landscapes and determined baseline concentrations of cytokines typically associated with chronic inflammation in older adults (TNF-α, IL-10, IL-6, and IFN-γ) in 30 high and 29 low influenza vaccine responders (HR and LR, respectively). In a background of high H3 antibody titers, vaccine-specific H3, but not H1, antibody titers were boosted in LRs to titers comparable to HRs. Pre-vaccination concentrations of IL-10 were higher in LRs compared with HRs and inversely correlated with titers of pre-existing influenza antibodies. Baseline TNF-α concentrations were positively correlated with fold-increases in antibody titers in HRs. Our findings indicate that baseline inflammatory status is an important determinant for generating post-vaccination hemagglutinin-inhibition antibodies in older adults, and IgG responses can be boosted in the context of high pre-existing immunity.

Effects and mechanism of perinatal nonylphenol exposure on cardiac function and myocardial mitochondria in neonatal rats.

BACKGROUND: Nonylphenol (NP) is a common environmental endocrine disruptor that is associated with the development of cardiovascular disease. However, the toxic effect of NP on mitochondria in the heart of offspring to exposed individuals remains exclusive. OBJECTIVE: To investigate whether perinatal NP exposure causes mitochondrial damage in the hearts of offspring of exposed individuals and determine its mechanism of action through both animal and cell experiments. METHODS AND RESULTS: For the in vivo experiment, pregnant rats were randomly divided into four groups: the control group (corn oil, C), low dose group (2.5 mg/kg/day, L-NP group), medium dose group (50 mg/kg/day, M-NP group), and high dose group (100 mg/kg/day, H-NP group), with 12 rats in each group. The NP concentration in the hearts of offspring at PND21 and PND90 increased with the increase of the NP dose. Perinatal NP exposure induced a gradual increase in systolic blood pressure in offspring at PND90. In the H-NP group, there was a high degree of inflammatory cell infiltration, myofibril breaks, inconspicuous or absent nuclei, and pink collagen deposition. At PND90, the membrane integrity of mitochondria in the H-NP group was disrupted, the cristae disorder was aggravated, and there was internal lysis with vacuolation. Compared to the control group, the mitochondrial membrane potential of offspring at PND21 and PND90 was decreased in each of the NP exposure groups. NP exposure decreased the activity of mitochondrial respiratory enzyme complex I (CI) and increased the activity of mitochondrial respiratory enzyme complex IV (CIV) in the offspring. At PND21 and PND90, the mRNA and protein expression levels of cardiac mitochondrial PGC-1α, NRF-1, and TFAM decreased with increasing NP dose in a dose-dependent manner. In the in vitro experiment, H9C2 cells were divided into the following four groups: the blank group, RSV group (15 µg/ml), RSV + NP group (15 µg/ml RSV + 120 mmol/L NP), and NP group (120 mmol/L). With increasing NP concentration, the cell survival rate gradually decreased. Compared to the control, the membrane potential was significantly decreased in the NP group; the protein expression levels of SIRT1, PGC-1α, NRF-1, and TFAM in the NP group were significantly lower. CONCLUSION: Perinatal NP exposure caused mitochondrial damage and dysfunction in the offspring of exposed individuals in a dose-dependent manner. This toxic effect may be related to NP-induced mitochondrial pathology in the offspring and the inhibition of both gene and protein expression involved in the PGC-1α/NRF-1/TFAM mitochondrial biogenesis signaling pathway following NP exposure.

Curative effect of zinc-selenium tea on rat's cardiotoxicity induced by long-term exposure to nonylphenol.

This study aimed to explore whether zinc-selenium tea has an curative effect on the cardiotoxicity induced by nonylphenol (NP), and to compare the effect of zinc-selenium tea and green tea. After drinking of zinc-selenium tea or green tea, compared with the control group, the left ventricular anterior wall became thinner, and the left ventricular end-diastolic diameter increased, the anterior wall of the left ventricle became thin at the end of diastole in the NP group. The serum myocardial enzymes aspartate aminotransferase, creatine kinase, creatine kinase isoenzyme, lactate dehydrogenase, and α-hydroxybutyrate dehydrogenase in the NP group were significantly increased, and the serum myocardial enzymes were significantly decreased after the intervention of zinc-selenium tea. Proteins and mRNA expressions of Collagen I and Collagen III in the tea groups were lower than those in the NP group. In the green tea and zinc-selenium tea intervention groups, the disorder and degree of myocardial fiber were alleviated to varying degrees. The disturbance, breakage, and inflammatory cell infiltration of myocardial fibers in zinc-selenium tea and green tea groups were less than that of NP group. After tea intervention, collagen I and collagen III in the myocardium decreased. The intervention effect of zinc-selenium tea was better than that of green tea. Zinc-selenium tea and green tea could interfere with the cardiotoxicity indued by NP, which would alleviate the myocardial fibrosis by reducing expressions of collagen I and collagen III. Moreover, the curative effect of zinc-selenium tea was better than that of green tea.

Antibody Responsiveness to Influenza: What Drives It?

The induction of a specific antibody response has long been accepted as a serological hallmark of recent infection or antigen exposure. Much of our understanding of the influenza antibody response has been derived from studying antibodies that target the hemagglutinin (HA) protein. However, growing evidence points to limitations associated with this approach. In this review, we aim to highlight the issue of antibody non-responsiveness after influenza virus infection and vaccination. We will then provide an overview of the major factors known to influence antibody responsiveness to influenza after infection and vaccination. We discuss the biological factors such as age, sex, influence of prior immunity, genetics, and some chronic infections that may affect the induction of influenza antibody responses. We also discuss the technical factors, such as assay choices, strain variations, and viral properties that may influence the sensitivity of the assays used to measure influenza antibodies. Understanding these factors will hopefully provide a more comprehensive picture of what influenza immunogenicity and protection means, which will be important in our effort to improve influenza vaccines.

Cloning and characterization of rec8 gene in orange-spotted grouper (Epinephelus coioides) and Dmrt1 regulation of rec8 promoter activity.

Meiosis is a specialized type of cell division critical for gamete production during sexual reproduction in eukaryotes. The meiotic recombination protein Rec8 has been identified as an important factor in germ cell meiotic initiation in vertebrates; however, its equivalent role in teleosts is poorly characterized. In this study, we cloned and sequenced the rec8 gene from orange-spotted grouper (Epinephelus coioides). The cDNA sequence consisted of 2244 base pairs (bp), including a 5' untranslated region (UTR) of 198 bp and a 3'UTR of 284 bp. The open reading frame of grouper rec8 was 1752 bp, encoding 584 amino acids. Expression levels of rec8 were higher in the ovary, intersex gonad, and testis. A neighbor-joining phylogenetic tree based on the deduced amino acid sequence indicated a common origin for grouper and other teleost rec8 molecules. Immunohistochemistry using a polyclonal anti-Rec8 antibody localized the protein in the oogonia and primary oocytes in the ovary and in spermatogonia and spermatocytes in the intersex gonad and testis, suggesting that Rec8 may play an important role in the meiotic division and the development of grouper germ cells. In addition, we found that the transcription factor Dmrt1 increased rec8 promoter activity through the second binding site, based on dual-luciferase assays. Together, these results suggest that Rec8 plays a crucial role in meiosis and may be regulated by Dmrt1 to affect meiosis in groupers.

Human post-infection serological response to the spike and nucleocapsid proteins of SARS-CoV-2.

To inform seroepidemiological studies, we characterized the IgG- responses in COVID-19 patients against the two major SARS-CoV-2 viral proteins, spike (S) and nucleocapsid (N). We tested 70 COVID-19 sera collected up to 85 days post-symptom onset and 230 non-COVID-19 sera, including 27 SARS sera from 2003. Although the average SARS-CoV-2 S and N-IgG titers were comparable, N-responses were more variable among individuals. S- and N-assay specificity tested with non-COVID-19 sera were comparable at 97.5% and 97.0%, respectively. Therefore, S will make a better target due to its lower cross-reactive potential and its' more consistent frequency of detection compared to N.

The public health response to the COVID-19 outbreak in mainland China: a narrative review.

The COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused nations to adopt unprecedented control measures in order to curb its spread. As the first nation to respond, China's aggressive control measures appeared to have been effective in suppressing the first wave and keeping new cases under control. Here, we provide the historical context and details of China's public health response to COVID-19. We highlight the lessons and impact of the 2002-2003 SARS outbreak, which demonstrated the importance of transparency, surveillance and testing laboratories during an outbreak. We provide an overview of China's response strategy that was based on the principles of early detection, isolation, management and treatment and involved not only the large-scale coordination of multiple governmental bodies but also grass-root community participation throughout the country. These community-based organizations conducted active surveillance for febrile cases and provided support for those in quarantine and communities in lockdown. Importantly, these broader measures were supported by digital technology, including the extensive use of internet-based platforms and mobile applications (APPs). While there have been no significant increases in case numbers since April, there is still much concern over a second wave, considering the resumption of work and school, the lifting of travel restrictions and the outbreaks occurring globally. Control measures has since been implemented by provincial authorities, which includes continued surveillance and rapid testing. Although China's strict control measures may not suit every nation, the principles of early detection and isolation continue to hold true and have been a cornerstone of the initial and ongoing response to the COVID-19.

Expression and subcellular analyses of CCR8a/b genes with the identification of response to SGIV viral infect in orange-spotted grouper (Epinephelus coioides).

Chemokine receptors are a superfamily of seven transmembrane domain G-coupled receptors, and they play important roles in immune surveillance, inflammation, and development. Recently, nine CC chemokine receptors (CCRs) were identified and cloned from orange-spotted grouper (Epinephelus coioides) and annotated by phylogenetic and syntenic analyses. We detected mRNA transcripts for CCRs in healthy tissues of E. coioides, and CCR genes were highly expressed in the immune-relevant tissues. Analysis of gene expression after Singapore grouper iridovirus (SGIV) infection indicated that CCR genes are regulated in a gene-specific manner. CCR8a and CCR8b were significantly upregulated in the spleen and liver of resistant fish, indicating potential roles in immunity against the pathogen. Fluorescence microscopy revealed that CCR8a and CCR8b were expressed predominantly in the cytoplasm. Overexpression of CCR8a and CCR8b in grouper cells significantly inhibited the replication of SGIV, demonstrating that they delayed the occurrence of cytopathic effects induced by SGIV infection and inhibited viral gene transcription. CCR8a and CCR8b overexpression also significantly increased the expression of interferon (IFN)-related cytokines and activated IFN response element and IFN promoter activities. These results demonstrated that CCR8a and CCR8b might have an antiviral function against SGIV infect.

In vitro effects of androgen on testicular development by the AR-foxl3-rec8/fbxo47 axis in orange-spotted grouper (Epinephelus coioides).

In orange-spotted grouper, androgen can promote the development of testis and spermatogenesis, but the effect of androgen on testis development is unclear. Forkhead box L 3 (Foxl3) is important in the development of fish testis. Rec8 and fbxo47 are involved in meiosis, which impacts spermatogenesis. The present study investigated the plausible role of testis development through the Foxl3 transcriptional regulation of rec8 and fbxo47. The results of tissue distribution showed that rec8 and fbxo47 are highly expressed in gonad. In addition, the highest expression of foxl3, rec8, and fbxo47 was in the testis and intersex compared with the other stages of gonadal development, suggesting that foxl3, rec8, and fbxo47 are important in testis development. In addition, by using dual-luciferase assays, we found that the androgen can increase foxl3 promoter activity and Foxl3 can upregulate rec8 and fbxo47 promoter activity. Furthermore, the addition of ß-testosterone significantly increased foxl3, rec8, and fbxo47 promoter activity. Together, these results suggest that foxl3 plays a decisive role in testis development by regulating the expression of rec8 or fbxo47 and imply that AR-foxl3-rec8/fbxo47 affects the testis development pathway.

Effect of starvation and refeeding on growth, gut microbiota and non-specific immunity in hybrid grouper (Epinephelus fuscoguttatus♀×E. lanceolatus♂).

Environmental changes can lead to food deprivation among aquatic animals. The main objective of this present research was to assess the effect of starvation and refeeding on growth, gut microbiota and non-specific immunity in a hybrid grouper (Epinephelus fuscoguttatus♀×E. lanceolatus♂). A total of 120 fish with an average weight of 74.16 ± 12.08 g were randomly divided into two groups (control group and fasted-refed group). The control group was fed until satiation for 60 days, while the fasted-refed group was fasted for 30 days and then fed to satiation for 30 days. The results showed that starvation led to a significantly decreased growth performance parameters [weight gain rate (WGR) and specific weight gain rate (SGR), while the feeding rate (FR) ] increased during the refeeding, non-specific immunity was significantly improved (p < 0.05) during the first 15 days of starvation, such as superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), lysozyme (LYM) and catalase (CAT). However, non-specific immunity decreased at 30 days of starvation, the expression of genes related to immunity, such as TNF-α, was upregulated (p < 0.05) during starvation, while the expression levels of IL-17 and IFN-γ was reduced (p < 0.05). The expression of IFN-γ and IL-1ß peaked during refeeding. Starvation led to significantly decreased abundance and diversity of intestinal microflora, with a higher abundance of Vibrio and a lower abundance of Brevibacillus, Bifidobacterium, Alloprevotella in the fasted-refed group during refeeding than in the control group. The above results reveal that starvation stimulates changes in growth, non-specific immunity, and the gut microbiota, providing new insights for the study of fish habitat selection and adaptability to environmental changes.

Assessment of the Effects of Bisphenol A on Dopamine Synthesis and Blood Vessels in the Goldfish Brain.

Bisphenol A (BPA) is an abundant contaminant found in aquatic environments. While a large number of toxicological studies have investigated the effects of BPA, the potential effects of BPA exposure on fish brain have rarely been studied. To understand how BPA impacts goldfish brains, we performed a transcriptome analysis of goldfish brains that had been exposed to 50 µg L-1 and 0 µg L-1 BPA for 30 days. In the analysis of unigene expression profiles, 327 unigenes were found to be upregulated and 153 unigenes were found to be downregulated in the BPA exposure group compared to the control group. Dopaminergic signaling pathway-related genes were significantly downregulated in the BPA exposure group. Furthermore, we found that serum dopamine concentrations decreased and TUNEL (terminal deoxynucleotidyl transferase 2-deoxyuridine, 5-triphosphate nick end labeling) staining was present in dopamine neurons enriched regions in the brain after BPA exposure, suggesting that BPA may disrupt dopaminergic processes. A KEGG analysis revealed that genes involved in the fluid shear stress and atherosclerosis pathway were highly significantly enriched. In addition, the qRT-PCR results for fluid shear stress and atherosclerosis pathway-related genes and the vascular histology of the brain showed that BPA exposure could damage blood vessels and induce brain atherosclerosis. The results of this work provide insights into the biological effects of BPA on dopamine synthesis and blood vessels in goldfish brain and could lay a foundation for future BPA neurotoxicity studies.

Functional analysis of the CXCR1a gene response to SGIV viral infection in grouper.

Chemokine receptors are a superfamily of seven-transmembrane domain G-coupled receptors and have important roles in immune surveillance, inflammation, and development. In previous studies, a series of CXCRs in grouper (Epinephelus coioides) was identified; however, the function of CXCR in viral infection has not been studied. To better understand the effect of the CXCR family on the fish immune response, full-length CXCR1a was cloned, and its immune response to Singapore grouper iridovirus (SGIV) was investigated. Grouper CXCR1a shared a seven-transmembrane (7-TM) region and a G protein-coupled receptor (GPCR) family 1 that contained a triaa stretch (DRY motif). Phylogenetic analysis indicated that CXCR1a showed the nearest relationship to Takifugu rubripes, followed by other fish, bird and mammal species. Fluorescence microscopy revealed that CXCR1a was expressed predominantly in the cytoplasm. Overexpression of CXCR1a in grouper cells significantly inhibited the replication of SGIV, demonstrating that CXCR1a delayed the occurrence of cytopathic effects (CPE) induced by SGIV infection and inhibited viral gene transcription. Furthermore, our results also showed that CXCR1a overexpression significantly increased the expression of interferon-related cytokines and activated ISRE and IFN promoter activities. Taken together, the results demonstrated that CXCR1a might have an antiviral function against SGIV infection.