Metabolomic changes and polyunsaturated fatty acid biosynthesis during gonadal growth and development in the sea urchin Strongylocentrotus intermedius

Investigating the mechanism of supraspinatus tendinopathy induced by type 2 diabetes mellitus in rats using untargeted metabolomics analysis

OBJECTIVE

To assess the mechanism of supraspinatus tendinopathy induced by type 2 diabetes mellitus (T2DM) in rats using untargeted metabolomics analysis.

METHODS

The liquid chromatography-mass spectrometry (LC-MS)-based untargeted metabolomics approach was used to screen tendon biomarkers of supraspinatus tendinopathy in rats with T2DM. Seventy-eight Sprague-Dawley rats were divided into normal group (NG) and T2DM groups. Rats in T2DM groups were divided into 12-week (T2DM-12w), and 24-week (T2DM-24w) subgroups according to the time point of the establishment of the T2DM rat model. Histological evaluation (modified Bonar score) and biomechanical testing were used to analyze the adverse effects of type 2 diabetes on the tendon of the supraspinatus muscle in rats.Three comparable groups were set up, including T2DM-12w group vs. NG, T2DM-24w group vs. NG, and T2DM-24w group vs. T2DM-12w group. Differentially expressed metabolites (DEMs) in the supraspinatus tendons in the three groups of rats were analyzed using LC-MS, and data were analyzed using multivariate statistical methods to screen potential biomarkers. The DEMs included in the intersection of the three groups were identified as those associated with the development of diabetic supraspinatus tendinopathy, and trend analysis and pathway topology analysis were performed.

RESULTS

With the progression of diabetes, the tendinopathy of the supracinatus muscle of diabetic rats gradually intensified, mainly manifested as inflammatory reactions, disordered collagen fibers, fat infiltration, and increased modified Bonar score. The intersection of DEMs among the three comparable groups was resulted in the identification of 10 key DEMs, in which melezitose and raffinose showed a continuous increasing trend with the prolongation of disease course. By pathway topology analysis, 10 DEMs (P < 0.01) were mainly associated with the pathways of galactose metabolism, which could be involved in the development of diabetes-induced supraspinatus tendinopathy.

CONCLUSION

T2DM causes tendinopathy of the supraspinatus muscle in rats. 10 key DEMs obtained by untargeted metabolomics assay suggested that the development of diabetes-induced supraspinatus tendinopathy was associated with changes in metabolic pathways, such as galactose metabolism. melezitose and raffinose hold promise as a biomarker for disease discrimination and/or disease indication in diabetic supraspinatus tendinopathy.

Nanopore sequencing demonstrates the roles of spermatozoal DNA N6-methyladenine in mediating transgenerational lipid metabolism disorder induced by excessive folate consumpton

Increased consumption of folic acid is prevalent due to its beneficial effects, but growing evidence emphasizes the side effects pointing to excessive dietary folate intake. The effects of excessive paternal folic acid consumption on offspring and its transgenerational inheritance mechanism have not been elucidated. We hypothesize that excessive folic acid consumption will alter sperm DNA N6-methyladenine (6mA) and 5-methylcytosine (5mC) methylation and heritably influence offspring metabolic homeostasis. Here, we fed roosters either folic acid-control or folic acid-excess diet throughout life. Paternal chronic folic acid excessive supplementation increased hepatic lipogenesis and lipid accumulation but reduced lipolysis both in the roosters and their offspring, which was further confirmed to be induced by one-carbon metabolism inhibition and gene expression alteration associated with the Peroxisome proliferator-activated receptor pathway. Based on the spermatozoal genome-wide DNA methylome identified by Nanopore sequencing, multi-omics association analysis of spermatozoal and hepatic DNA methylome, transcriptome, and metabolome suggested that differential spermatozoal DNA 6mA and 5mC methylation could be involved in regulating lipid metabolism-related gene expression in offspring chickens. This model suggests that sperm DNA N6-methyladenine and 5-methylcytosine methylation were involved in epigenetic transmission and that paternal dietary excess folic acid leads to hepatic lipid accumulation in offspring.

Multi-Omics Integrative Analysis to Reveal the Impacts of Shewanella algae on the Development and Lifespan of Marine Nematode Litoditis marina

Understanding how habitat bacteria affect animal development, reproduction, and aging is essential for deciphering animal biology. Our recent study showed that Shewanella algae impaired Litoditis marina development and lifespan, compared with Escherichia coli OP50 feeding; however, the underlying mechanisms remain unclear. Here, multi-omics approaches, including the transcriptome of both L. marina and bacteria, as well as the comparative bacterial metabolome, were utilized to investigate how bacterial food affects animal fitness and physiology. We found that genes related to iron ion binding and oxidoreductase activity pathways, such as agmo-1, cdo-1, haao-1, and tdo-2, were significantly upregulated in L. marina grown on S. algae, while extracellular structural components-related genes were significantly downregulated. Next, we observed that bacterial genes belonging to amino acid metabolism and ubiquinol-8 biosynthesis were repressed, while virulence genes were significantly elevated in S. algae. Furthermore, metabolomic analysis revealed that several toxic metabolites, such as puromycin, were enriched in S. algae, while many nucleotides were significantly enriched in OP50. Moreover, we found that the "two-component system" was enriched in S. algae, whereas "purine metabolism" and "one-carbon pool by folate" were significantly enriched in E. coli OP50. Collectively, our data provide new insights to decipher how diet modulates animal fitness and biology.

Characteristics of gut microbiota and metabolomic of Hainan Tunchang pigs at various growth stages

Numerous gut microorganisms residing in the gut tract and their metabolites play an important role in animal growth. Diet, as the main factor, affects the changes of gut microbiota, and host genetics also have a significant impact on gut microbiota, including growth stages. However, the differences of gut microbiota and its metabolites at various growth stages in local pig breed remains unclear. We used 16S rRNA gene sequencing and untargeted metabolomics to investigate the fecal microbiota and metabolites in different developmental stages of Hainan Tunchang pigs. The relative proportions of dominant bacteria Firmicutes and Spirochaetes increased, Bacteroidetes and Proteobacteria decreased with the development. As age increased, different physiological states led to structural and functional changes in animal nutrition metabolism and immune needs, as well as changes in gut microbiota and its metabolites. We have detected several statistically different microbial and metabolic biomarkers at different growth stages. Meanwhile, through correlation analysis between differential bacteria and metabolites, it was found that the bacteria forming networks with their significant related metabolites were different at various growth stages, Holdemanella, Sharpea, Subdoligranulum, and uncultured_bacterium_o_Bacteroidales were enriched between preweaning piglets and weaning piglets, and they all positive correlated with related metabolites. We also found that the differential bacteria were significantly related to short-chain fatty acid. These findings might provide new insights into the developmental changes of gut microbiota in local pig breeds and the interaction mechanism between the body, and improve pig growth performance and efficiency by regulating the composition of gut microbiota and metabolites.

Lipid overload-induced RTN3 activation leads to cardiac dysfunction by promoting lipid droplet biogenesis

Lipid droplet (LD) accumulation is a notable feature of obesity-induced cardiomyopathy, while underlying mechanism remains poorly understood. Here we show that mice fed with high-fat diet (HFD) exhibited significantly increase in cardiac LD and RTN3 expression, accompanied by cardiac function impairment. Multiple loss- and gain-of function experiments indicate that RTN3 is critical to HFD-induced cardiac LD accumulation. Mechanistically, RTN3 directly bonds with fatty acid binding protein 5 (FABP5) to facilitate the directed transport of fatty acids to endoplasmic reticulum, thereby promoting LD biogenesis in a diacylglycerol acyltransferase 2 dependent way. Moreover, lipid overload-induced RTN3 upregulation is due to increased expression of CCAAT/enhancer binding protein α (C/EBPα), which positively regulates RTN3 transcription by binding to its promoter region. Notably, above findings were verified in the myocardium of obese patients. Our findings suggest that manipulating LD biogenesis by modulating RTN3 may be a potential strategy for treating cardiac dysfunction in obese patients.

The toxicological effects of life-cycle exposure to harmful benthic cyanobacteria Oscillatoria on zebrafish growth and reproduction: A comparative study with planktonic Microcystis

The risks of planktonic cyanobacteria blooms have been the focus of much scientific research, but studies on the ecotoxicological effects of benthic cyanobacteria are lagging. The impacts of cyanobacteria cells on fish populations might be more complex in contrast to purified cyanotoxins or cyanobacteria extracts. This study systematically compared the chronic effects of benthic Oscillatoria sp. (producing cylindrospermopsins) and planktonic Microcystis aeruginosa (producing microcystins) on the growth and reproduction of zebrafish through life-cycle exposure (5- 90 days post fertilization). The results showed that both Oscillatoria sp. and M. aeruginosa exposure caused growth inhibition and fecundity reduction in F0 generation by disrupting sex hormone levels, delayed ovarian and sperm development, and induced pathological lesions in zebrafish gonads. Furthermore, exposure to Oscillatoria sp. or M. aeruginosa in adult zebrafish increased mortality and teratogenicity in F1 embryos (without exposure), indicating a parental transmission effect of developmental toxicity. The difference was that M. aeruginosa exposure led to significant alterations in pathways, such as tissue development, redox processes, and steroid hormone synthesis. In contrast, Oscillatoria sp. exposure primarily disrupted the PPAR signaling pathway, cell adhesion molecules, and lipid transport pathways. Interestingly, the differentially expressed genes revealed that male fish were more sensitive to harmful cyanobacteria than females, whether exposed to Oscillatoria sp. or M. aeruginosa. These findings contribute to a better mechanistic understanding of the chronic toxic effects of distinct types of harmful cyanobacteria, suggesting that the ecological risk of benthic cyanobacteria requires further attention.

Fatty Acid Metabolism in Peroxisomes and Related Disorders

One of the functions of peroxisomes is the oxidation of fatty acids (FAs). The importance of this function in our lives is evidenced by the presence of peroxisomal disorders caused by the genetic deletion of proteins involved in these processes. Unlike mitochondrial oxidation, peroxisomal oxidation is not directly linked to ATP production. What is the role of FA oxidation in peroxisomes? Recent studies have revealed that peroxisomes supply the building blocks for lipid synthesis in the endoplasmic reticulum and facilitate intracellular carbon recycling for membrane quality control. Accumulation of very long-chain fatty acids (VLCFAs), which are peroxisomal substrates, is a diagnostic marker in many types of peroxisomal disorders. However, the relationship between VLCFA accumulation and various symptoms of these disorders remains unclear. Recently, we developed a method for solubilizing VLCFAs in aqueous media and found that VLCFA toxicity could be mitigated by oleic acid replenishment. In this chapter, we present the physiological role of peroxisomal FA oxidation and the knowledge obtained from VLCFA-accumulating peroxisome-deficient cells.

Identification of postnatal development dependent genes and proteins in porcine epididymis

BACKGROUND

The epididymis is a highly regionalized tubular organ possesses vectorial functions of sperm concentration, maturation, transport, and storage. The epididymis-expressed genes and proteins are characterized by regional and developmental dependent pattern. However, a systematic and comprehensive insight into the postnatal development dependent changes in gene and protein expressions of porcine epididymis is still lacking. Here, the RNA and protein of epididymis of Duroc pigs at different postnatal development stages were extracted by using commercial RNeasy Midi kit and extraction buffer (7 M Urea, 2 M thiourea, 3% CHAPS, and 1 mM PMSF) combined with sonication, respectively, which were further subjected to transcriptomic and proteomic profiling.

RESULTS

Transcriptome analysis indicated that 198 and 163 differentially expressed genes (DEGs) were continuously up-regulated and down-regulated along with postnatal development stage changes, respectively. Most of the up-regulated DEGs linked to functions of endoplasmic reticulum and lysosome, while the down-regulated DEGs mainly related to molecular process of extracellular matrix. Moreover, the following key genes INSIG1, PGRMC1, NPC2, GBA, MMP2, MMP14, SFRP1, ELN, WNT-2, COL3A1, and SPARC were highlighted. A total of 49 differentially expressed proteins (DEPs) corresponding to postnatal development stages changes were uncovered by the proteome analysis. Several key proteins ACSL3 and ACADM, VDAC1 and VDAC2, and KNG1, SERPINB1, C3, and TF implicated in fatty acid metabolism, voltage-gated ion channel assembly, and apoptotic and immune processes were emphasized. In the integrative network, the key genes and proteins formed different clusters and showed strong interactions. Additionally, NPC2, COL3A1, C3, and VDAC1 are located at the hub position in each cluster.

CONCLUSIONS

The identified postnatal development dependent genes and proteins in the present study will pave the way for shedding light on the molecular basis of porcine epididymis functions and are useful for further studies on the specific regulation mechanisms responsible for epididymal sperm maturation.

Untargeted metabolomics reveals dynamic changes in metabolic profiles of rat supraspinatus tendon at three different time points after diabetes induction

Objective

To investigate the dynamic changes of metabolite composition in rat supraspinatus tendons at different stages of diabetes by untargeted metabolomics analysis.

Methods

A total of 80 Sprague-Dawley rats were randomly divided into normal (NG, n = 20) and type 2 diabetes mellitus groups (T2DM, n = 60) and subdivided into three groups according to the duration of diabetes: T2DM-4w, T2DM-12w, and T2DM-24w groups; the duration was calculated from the time point of T2DM rat model establishment. The three comparison groups were set up in this study, T2DM-4w group vs. NG, T2DM-12w group vs. T2DM-4w group, and T2DM-24w group vs. T2DM-12w group. The metabolite profiles of supraspinatus tendon were obtained using tandem mass spectrometry. Metabolomics multivariate statistics were used for metabolic data analysis and differential metabolite (DEM) determination. The intersection of the three comparison groups' DEMs was defined as key metabolites that changed consistently in the supraspinatus tendon after diabetes induction; then, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was performed.

Results

T2DM-4w group vs. NG, T2DM-12w group vs. T2DM-4w group, and T2DM-24w group vs. T2DM-12w group detected 94 (86 up-regulated and 8 down-regulated), 36 (13 up-regulated and 23 down-regulated) and 86 (24 up-regulated and 62 down-regulated) DEMs, respectively. Seven key metabolites of sustained changes in the supraspinatus tendon following induction of diabetes include D-Lactic acid, xanthine, O-acetyl-L-carnitine, isoleucylproline, propoxycarbazone, uric acid, and cytidine, which are the first identified biomarkers of the supraspinatus tendon as it progresses through the course of diabetes. The results of KEGG pathway enrichment analysis showed that the main pathway of supraspinatus metabolism affected by diabetes (p < 0.05) was purine metabolism. The results of the KEGG metabolic pathway vs. DEMs correlation network graph revealed that uric acid and xanthine play a role in more metabolic pathways.

Conclusion

Untargeted metabolomics revealed the dynamic changes of metabolite composition in rat supraspinatus tendons at different stages of diabetes, and the newly discovered seven metabolites, especially uric acid and xanthine, may provide novel research to elucidate the mechanism of diabetes-induced tendinopathy.

Sex-specific seasonal variations in the fatty acid and carotenoid composition of sea cucumber gonads and implications for aquaculture

Fatty acids and carotenoids are known to have roles in embryonic and larval development of sea cucumbers, but their changes in gonads during gametogenesis have not yet been studied. To improve our knowledge of the reproductive cycle of sea cucumbers in an aquaculture perspective, we collected 6-11 individuals of the species Holothuria (Panningothuria) forskali Delle Chiaje, 1823 approximately every 2 months from December 2019 to July 2021 east of the Glenan Islands (Brittany - France; 47.710°N, 3.948°W) at a depth of 8-12 m. Our results show that soon after spawning, sea cucumbers take advantage of an increased food availability in spring to rapidly and opportunistically accumulate nutrients in the form of lipids in their gonads (from May to July) and then slowly elongate, desaturate and probably rearrange fatty acids within lipid classes for the next reproductive season according to the specific requirements of both sexes. In contrast, acquisition of carotenoids occurs synchronously with gonads filling and/or through the reabsorption of spent tubules (T5), thus revealing little seasonal variations at the scale of the entire gonad in terms of relative abundance in both sexes. All results suggest that gonads are fully replenished with nutrients by October and that broodstock for induced reproduction could be captured at this moment and kept until the production of larvae is required. Maintaining broodstock for consecutive years would probably be a higher level challenge as the dynamics of tubule recruitment are not fully understood and seem to last for several years.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00227-023-04198-0.

Plastic leachate-induced toxicity during sea urchin embryonic development: Insights into the molecular pathways affected by PVC

Microplastics are now polluting all seas and, while studies have found numerous negative interactions between plastic pollution and marine animals, the effects on embryonic development are poorly understood. A potentially important source of developmental ecotoxicity comes from chemicals leached from plastic particles to the marine environment. Here we investigate the effects of leachates from new and beach-collected pellets on the embryonic and larval development of the sea urchin Strongylocentrotus purpuratus and demonstrate that exposure of developing embryos to these leachates elicits severe, consistent and treatment-specific developmental abnormalities including radialisation of the embryo and malformation of the skeleton, neural and immune cells. Using a multi-omics approach we define the developmental pathways disturbed upon exposure to PVC leachates and provide a mechanistic view that pinpoints cellular redox stress and energy production as drivers of phenotypic abnormalities following exposure to PVC leachates. Analysis of leachates identified high concentrations of zinc that are the likely cause of these observed defects. Our findings point to clear and specific detrimental effects of marine plastic pollution on the development of echinoderms, demonstrating that chemicals leached from plastic particles into sea water can produce strong developmental abnormalities via specific pathways, and therefore have the potential to impact on a wide range of organisms.

Hepatopancreas transcriptome analyses provide new insights into the molecular regulatory mechanism of fast ovary maturation in Macrobrachium nipponense

Background

Macrobrachium nipponense is an economically and ecologically important freshwater prawn that is widely farmed in China. In contrast to other species of marine shrimp, M. nipponense has a short sexual maturity period, resulting in not only high stocking densities, but also a reduced survival rate and increased risk of hypoxia. Therefore, there is an urgent need to study the molecular mechanisms underlying fast ovary maturation in this species.

Results

Comparative transcriptome analysis was performed using hepatopancreatic tissue from female M. nipponense across five ovarian maturation stages to explore differentially expressed genes and pathways involved in ovarian maturation. In total, 118.01 Gb of data were generated from 15 transcriptomes. Approximately 90.46% of clean reads were mapped from the M. nipponense reference genome. A comprehensive comparative analysis between successive ovarian maturation stages generated 230–5814 differentially expressed genes. Gene Ontology (GO) enrichment was highly concentrated in the “biological process” category in all four comparison groups, and mainly focused on energy synthesis and accumulation, energy decomposition and transport. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment results showed that, among 20 significantly enriched KEGG pathways, nine were involved in the synthesis, degradation, and metabolism of carbohydrates, lipids, and other nutrient intermediates, suggesting that the hepatopancreas has an important role in energy supply during ovarian maturation. Furthermore, the “Insect hormone biosynthesis” pathway was found to have a dominant role in the development of the ovary from immaturity to maturity, supporting the hypothesis that ecdysteroid- and juvenile hormone-signaling pathways have an important role in hepatopancreas regulation of ovarian maturation.

Conclusion

Taken together, this study sheds light on the role of the hepatopancreas in the molecular regulation of ovary maturation in M. nipponense. The present study provided new insights for understanding the mechanisms of reproductive regulation in crustaceans.

The arachidonic acid and its metabolism pathway play important roles for Apostichopus japonicus infected by Vibrio splendens

Improving the immune ability and guiding healthy culture for sea cucumber by purposefully screening the significant differential metabolites when Apostichopus japonicus (A. japonicus) is infected by pathogens is important. In this study, 35 types of significant differential metabolites appeared when A. japonicus were infected by Vibrio splendens (VSI group) compared with the control A. japonicus group (CK group) by using liquid chromatography-mass spectrometry (LC-MS/MS)-based untargeted metabolomics. Based on that finding, the 10 types of key metabolic pathways were analyzed by MetPA. The "arachidonic acid (ARA) metabolism" pathway, which was screened by three elevated biomarkers: ARA, prostaglandin F2α and 2-arachidonoyl glycerol, had an important impact on immune stress in A. japonicus. Due to the similar changes in several metabolites in its metabolic pathway, the ARA metabolic pathway was selected for further study. The activities of ACP, AKP and lysozyme, which are important innate immune-related enzymes, the survival rates of A. japonicus infected with V. splendidus and the relative content of ARA in the body wall detected by GC-MS were all upregulated significantly by exogenous daily 0.60% and 1.09% ARA consumption over a short period of approximately 7 days. These results demonstrated that ARA and its metabolic pathway indeed played important roles in the immunity of A. japonicus infected by the pathogen. The findings also provide novel insights for the effects of metabolites in A. japonicum healthy culture.

Transcriptomic and Metabolomic Analyses Provide Insights into the Growth and Development Advantages of Triploid Apostichopus japonicus

Polyploid breeding is widely used in aquaculture as an important area of new research. We have previously grown Apostichopus japonicus triploids with a growth advantage. The body length, body weight, and aestivation time of triploid and diploid A. japonicus were measured in this study, and the transcriptome and metabolome were used to examine the growth advantage of triploids A. japonicus. The results showed that the proportion of triploid A. japonicus with a body length of 6-12 cm and 12-18 cm was significantly higher than that of diploid A. japonicus, and triploid A. japonicus had a shorter aestivation time (39 days) than diploid (63 days). We discovered 3296 differentially expressed genes (DEGs); 13 DEGs (for example, cyclin-dependent kinase 2) related to growth advantage, immune regulation, and energy storage were screened as potential candidates. According to Gene Ontology (GO) enrichment analysis, DEGs were significantly enriched in the cytoplasm (cellular component), ATP binding process (molecular function), oxidation-reduction process (biological process), and other pathways. According to the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment data, DEGs were significantly enriched in ribosome production and other areas. We discovered 414 significant differential metabolites (SDMs), with 11 important SDMs (for example, nocodazole) linked to a growth advantage. SDMs are significantly enriched in metabolic pathways, as well as other pathways, according to the KEGG enrichment results. According to a combined transcriptome and metabolome analysis, 6 DEGs have regulatory relationships with 11 SDMs, which act on 11 metabolic pathways together. Our results further enrich the biological data of triploid A. japonicus and provide useful resources for genetic improvement of this species.

Unraveling the innate immune responses of Bombyx mori hemolymph, fat body, and midgut to Bombyx mori nucleopolyhedrovirus oral infection by metabolomic analysis

Bombyx mori nucleopolyhedrovirus (BmNPV) infection causes a series of physiological and pathological changes in Bombyx mori (B. mori). Here, a metabolomic study of the innate immunity organs including hemolymph, fat body, and midgut of the silkworm strain Dazao following BmNPV challenge was conducted to reveal the metabolic variations in B. mori. Compared to the control, 4964 and 4942 features with 4077 and 4327 high-quality features were generated under positive and negative modes, respectively, from BmNPV-infected larvae. The principal component analysis and supervised learning method using partial least squares discrimination analysis demonstrated good analytical stability and experimental reproducibility of the metabolic profiles. Based on database annotations, a total of 296, 108, and 215 differential expressed metabolites (DEMs) were identified from BmNPV-infected group of hemolymph, fat body, and midgut, respectively, which were all mainly grouped into carboxylic acids and derivatives, fatty acyls, and glycerophospholipids. Kyoto Encyclopedia of Genes and Genomes Database enrichment analysis of the DEMs showed that amino acid metabolism was increased at 24 h after BmNPV infection. BmNPV induction was adopted to significantly alter a series of immune-related pathways including phospholipase D signaling pathway, FoxO signaling pathway, metabolism of xenobiotics by cytochrome P450, melanogenesis, membrane transport, carbohydrate metabolism, and lipid metabolism. The different levels of expression of several DEMs including l-glutamate, naphthalene, 3-succinoylpyridine 1-acyl-sn-glycerol 3-phosphate, and l-tyrosine which were involved in those pathways exhibited the immune responses of B. mori to BmNPV infection. Our findings are valuable for a better understanding of the antiviral mechanism of B. mori underlying the interaction between the silkworm and BmNPV.

Resveratrol Attenuates Diquat-Induced Oxidative Stress by Regulating Gut Microbiota and Metabolome Characteristics in Piglets

Previous studies have shown that dietary resveratrol (RES) reduces diarrhea and attenuates oxidative stress in piglets challenged with diquat. However, the effect of dietary resveratrol on the gut microbiota of these piglets, as well as the potential relationships between intestinal microflora and metabolites, remain unclear. Here, 16S ribosomal DNA sequencing and metabolome analyses were performed to investigate the effect of RES on the gut microbiota and metabolome of diquat-challenged piglets. A total of 18 weaned piglets (aged 28 ± 2 days) were divided into the control group (basal diet), diquat group (basal diet + diquat challenge), and RES group (basal diet containing 90 mg/kg RES + diquat challenge). Compared with the control group, piglets in the diquat group showed enriched relative abundance of the phyla Firmicutes and Actinobacteria, the genus Ruminococcaceae UCG-005, and members of the Eubacterium coprostanoligenes group. Noteworthy, RES supplementation significantly reduced the levels of these microorganisms. In contrast, the relative abundance of some beneficial bacterial species in the RES group, such as the genera Clostridium sensu stricto 1 and Lachnospiraceae unclassified were significantly higher than in the diquat and control groups. Metabolomic analysis indicated that some metabolites, including indole-3-carbinol, 5-hydroxyindole-3-acetic acid, and uridine, were significantly upregulated upon RES supplementation. In particular, the relative abundance of uridine, indole, and alpha- and beta-dihydroresveratrol was significantly higher in the RES group than in the control group. Moreover, most gut bacterial genera were found to be highly correlated with altered gut microbiota-related metabolites. These findings suggest that dietary supplementation with resveratrol may alter the composition and metabolites of colonic microbiota in diquat-challenged piglets, which provides important insights into the use of resveratrol as a feed additive for gut microbial regulation in piglets with inflammatory and oxidative stress-associated disorders.

Multi-omics analysis reveals the glycolipid metabolism response mechanism in the liver of genetically improved farmed Tilapia (GIFT, Oreochromis niloticus) under hypoxia stress

BACKGROUND

Dissolved oxygen (DO) in the water is a vital abiotic factor in aquatic animal farming. A hypoxic environment affects the growth, metabolism, and immune system of fish. Glycolipid metabolism is a vital energy pathway under acute hypoxic stress, and it plays a significant role in the adaptation of fish to stressful environments. In this study, we used multi-omics integrative analyses to explore the mechanisms of hypoxia adaptation in Genetically Improved Farmed Tilapia (GIFT, Oreochromis niloticus).

RESULTS

The 96 h median lethal hypoxia (96 h-LH50) for GIFT was determined by linear interpolation. We established control (DO: 5.00 mg/L) groups (CG) and hypoxic stress (96 h-LH50: 0.55 mg/L) groups (HG) and extracted liver tissues for high-throughput transcriptome and metabolome sequencing. A total of 581 differentially expressed (DE) genes and 93 DE metabolites were detected between the CG and the HG. Combined analyses of the transcriptome and metabolome revealed that glycolysis/gluconeogenesis and the insulin signaling pathway were down-regulated, the pentose phosphate pathway was activated, and the biosynthesis of unsaturated fatty acids and fatty acid metabolism were up-regulated in GIFT under hypoxia stress.

CONCLUSIONS

The results show that lipid metabolism became the primary pathway in GIFT under acute hypoxia stress. Our findings reveal the changes in metabolites and gene expression that occur under hypoxia stress, and shed light on the regulatory pathways that function under such conditions. Ultimately, this information will be useful to devise strategies to decrease the damage caused by hypoxia stress in farmed fish.

Transcriptome analysis to characterize the genes related to gonad growth and fatty acid metabolism in the sea urchin Strongylocentrotus intermedius

BACKGROUND

Sea urchin gonads of both sexes, commonly termed "roe", are highly valued seafood delicacies, and Strongylocentrotus intermedius is considered one of the tastiest sea urchins. In order to produce high-quality gonads for consumption and clarify the mechanism of gonad growth and development of the sea urchin, more genetic information, especially at the transcriptome level, is needed.

OBJECTIVE

A more thorough understanding of sea urchin gonad growth and development in both sexes could enable regulation of these processes at several stages with the aim of suppressing gametogenesis in order to produce high-quality gonads for consumption.

METHODS

The adult sea urchins S. intermedius were cultured for 3 months, and were sampled for the gonadal transcriptome analysis which has been performed on the RNAs of three male and female adults of S. intermedius in each gonad development stage.

RESULTS

Illumina sequencing raw sequence data was deposited in the NCBI Sequence Read Archive (SRA) database (PRJNA532998). It generated 560,196,356 raw reads and 548,956,944 clean reads were acquired, which were assembled into 107,850 transcripts with 44,124 genes. Comparative analysis showed the differentially expressed genes (DEGs) from 114 to 2566. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were used to determine the functional significance of these DEGs. We have selected 9 genes related to growth and 12 genes related to fatty acid biosynthesis and metabolism in sea urchin gonads.

CONCLUSION

These data for sea urchins were intended to provide markers for gonad growth and development that can be accumulated for use in aquaculture applications.