理学最新文献

Background: Improving meat quality through nutritional regulation is an important approach in ruminant production. Growing evidence suggests that rumen microbiota influences host metabolism via microbial metabolites, thereby affecting meat quality. However, whether Piper sarmentosum Roxb. extract (PSE), a medicinal and edible plant-derived extract, improves meat quality through rumen microbiota-host metabolic interactions remains unclear. Thirty-six weaned male Hainan black goats (approximately 3 months old) were randomly assigned to four dietary treatments supplemented with 0, 200, 400, or 600 mg/kg PSE (dry matter basis), respectively. After a 90-day feeding trial, goats were fasted for 12 h before slaughter, and rumen and longissimus lumborum muscle samples were collected for subsequent analyses.

Results: Supplementation with 600 mg/kg PSE significantly enhanced meat quality traits, including higher ultimate pH, improved color stability, and increased water-holding capacity, without affecting growth performance or carcass traits. Transcriptomic and metabolomic analyses revealed that PSE supplementation was associated with remodeling of amino acid and energy metabolism in muscle, particularly glutamate-related pathways. These metabolic changes were accompanied by increased expression of key metabolic genes, including BCAT2, IDH1, and IDH3A, alongside alterations in energy-related metabolites, such as the downregulation of carnitine and upregulation of creatinine. Concomitant shifts in rumen microbial composition were observed, with PSE supplementation increasing the abundance of genera like Weissella and Ruminococcus, while reducing potentially opportunistic genera, such as Acinetobacter and Klebsiella. Weissella showed strong positive correlations with elevated rumen metabolites like serine, threonine, choline, and hypoxanthine. Metagenome-assembled genome analysis of Weissella cibaria revealed an enrichment of genes related to amino acid metabolism and glycosyltransferase families. Correlation and mediation analyses further revealed associations among Weissella abundance, rumen metabolites, and muscle metabolic traits, supporting a potential microbiota-metabolite-host metabolic relationship.

Conclusions: Collectively, this study provides new insights into the association network linking PSE-induced alterations in rumen microbiota, microbial metabolites, and host muscle metabolism in relation to goat meat quality. These findings suggest that PSE supplementation may improve meat quality through coordinated changes in rumen microbial ecology and muscle metabolic profiles.

Background: The decline in egg production in aging hens poses a significant challenge to sustainable poultry production. Given that evidence suggests the phosphorus source affects late‑lay performance, we tested the hypothesis that the dietary phosphorus source is a decisive regulator sustaining performance by reprogramming systemic mineral homeostasis. Using a systems biology approach, we analyzed the coordinated expression of eleven key mineral transporter genes across the duodenum, jejunum, ileum, and kidney of hens fed dicalcium phosphate (DCP) or tricalcium phosphate (TCP).

Results: During weeks 5-8, hens fed DCP showed significant declines in egg production (β = -3.11/week, P < 0.001) and egg weight (β = -0.47 g/week, P = 0.049), unlike the stable TCP group. TCP induced an efficient "precision conservation" phenotype, characterized by the co-upregulation of key duodenal phosphorus and calcium transporters (NaPi-IIb, PiT2; NCX1, PMCA1b), a gene set identified as the top predictor of performance. Conversely, DCP triggered a costly "compensatory salvage" state, scattering expression to duodenal calcium channels (TRPV5, TRPV6) and renal compensatory genes (NCX1, CALB1). Network analysis pinpointed these renal genes as a central, performance-limiting hub.

Conclusion: We conclude that TCP sustains production by programming a systemically efficient homeostatic strategy, thereby explaining the established performance benefit at a molecular level. This establishes a new principle for layer nutrition: phosphorus source selection must consider its role as a physiological signal that modulates homeostasis. This strategy mitigates age-related decline and enhances resource allocation to production.

Background: In commercial production, the absence of adult hens disrupts natural gut colonization, forcing chicks to rely on environmental microbes and potentially compromising the ecological succession essential for health. This study investigated whether early-life adult hen microbial contact could optimize the intestinal community and metabolite profiles, thereby mitigating lipopolysaccharide (LPS)-induced immunological stress in broilers. Accordingly, 128 one-day-old broilers were assigned to control or adult hen microbial contact groups. Hens were removed on D 10, and LPS was administered on D 18 and D 20, resulting in a 2 × 2 factorial design.

Results: Adult hen microbial contact did not affect body weight or ileal histomorphology on D 10 or D 21. However, it reshaped the alpha diversity (P < 0.05) and beta diversity (P < 0.05) of the cecal microbiota, enriching beneficial genera such as Bacteroides, Prevotellaceae, Rikenellaceae, Muribaculaceae, and Megasphaera, although these were not primarily established through direct adult hen transfer. These microbial alterations were accompanied by increased production of cecal volatile fatty acids (P < 0.05) and altered tryptophan metabolism (P < 0.05), characterized by the conversion of serum tryptophan to indoleacetic acid. In the ileum, the adult hen microbial contact upregulated (P < 0.05) genes associated with mucosal barrier integrity (MUC13, CLDN2) and antioxidant defense (SOD2, FOXO1), while independently downregulating (P < 0.05) hepatic genes involved in redox regulation and autophagy (GRX5, LC3-1). LPS challenge induced a pronounced (P < 0.05) antioxidant imbalance in the ileum, characterized by the downregulation of CAT and NRF2, together with elevated expression of pro-inflammatory cytokines (IL8, IFNA, TNFA), compromising barrier function (MUC13, CLDN2). Concurrently, the LPS challenge increased (P < 0.05) the expression of hepatic genes involved in redox regulation and autophagy (GRX5, LC3-1), consistent with a systemic stress response. Notably, microbial contact attenuated the LPS-induced reduction in valeric acid (P < 0.05), suggesting a protective effect on microbial metabolite production under immunological stress.

Conclusion: Adult hen microbial contact did not improve growth performance or ileal histomorphology, but shaped the early-life gut microbiota and associated metabolite profiles, contributing to improved resilience to subsequent immune challenges in broilers.

Background: Hu sheep are highly prolific, but litter size remains variable among individuals. How ovarian metabolism and somatic-cell heterogeneity are associated with this variation remains unclear. Ovarian metabolites from high-litter-size (HLS) and low-litter-size (LLS) Hu ewes were profiled by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. Ovarian cell populations and transcriptional states were characterized by single-cell RNA sequencing. Integrated analyses were used to relate metabolic differences to specific cell populations and predicted cell-cell communication. RT-qPCR and multiplex immunofluorescence were used to examine selected metabolic genes and the endothelial localization of ESM1. Separate cell experiments assessed the effects of endothelial cell-conditioned medium (EC-CM) and recombinant human IGFBP3 on primary ovine granulosa cells (GCs), with TMEM219 knockdown used to evaluate receptor involvement.

Results: HLS ovaries showed higher L-carnitine abundance, whereas several representative sphingomyelin species were more abundant in LLS ovaries (nominal P < 0.05). Integrated analysis identified two EC associated genes: DNAJB4 was downregulated, whereas NDRG1 was upregulated in HLS ovaries (P < 0.05). At the EC level, gene set enrichment analysis showed significant enrichment of glutathione metabolism and oxidative phosphorylation in the HLS group. EC subclustering further associated these transcriptional programs with ESM1⁺ angiogenic endothelial cells (A-ECs). Multiplex immunofluorescence localized ESM1 to VWF-positive vascular structures and showed a significantly larger ESM1-positive area and more VWF/ESM1 double-positive cells in HLS ovaries (P < 0.05). Cell-cell communication analysis identified IGFBP3-TMEM219 as a candidate EC-GC interaction. IGFBP3 was detected in EC-conditioned medium, which significantly reduced EdU incorporation and the expression of CYP11A1, FSHR and STAR (P < 0.05) in granulosa cells. Recombinant IGFBP3 produced similar responses, and TMEM219 knockdown partially attenuated several of these effects.

Conclusions: This study identified an association between exploratory ovarian metabolic patterns and EC heterogeneity, while functional experiments showed that EC-derived IGFBP3 affected GC function partly through TMEM219. These findings suggest that endothelial state and signaling may be relevant to follicular development, although whether IGFBP3-TMEM219 signaling contributes to litter-size variation in Hu sheep remains to be established.

Background: Embryo genomic selection (EGS) refers to the technique of performing genotyping and genomic prediction at the preimplantation stage. When combined with in vitro embryo production method, EGS enhances selection intensity and offers the potential to prevent the birth of offspring carrying genetic defects or an undesired sex. Given that the somatic cell nuclear transfer (SCNT) technique can copy the genetic information from donor pigs into early embryos, this study aims to establish and validate a complete porcine EGS workflow by integrating SCNT with genomic selection methodology.

Results: First, porcine SCNT embryos were constructed using donor cells collected from candidate pigs with known genotypes and phenotypes. Cell biopsy performed in SCNT embryos revealed that collecting approximately 9.5 trophectoderm (TE) cells from blastocysts had the least impact on subsequent development. Next, a whole-genome multiple displacement amplification protocol was optimized for TE biopsy cells to conduct 80 K single nucleotide polymorphism (SNP) array analysis. The SNP call rates ranged from 94.44% to 99.77%, with genotype concordance between SCNT embryos and their donor pigs mostly exceeding 95%. Finally, genomic estimated breeding values (GEBVs) for three production traits were calculated using the GBLUP and Bayesian methods, and strong positive correlations (r > 0.90) of GEBVs were observed for each embryo and its donor.

Conclusions: This study establishes and validates a complete EGS workflow for pigs, including embryo biopsy, whole-genome amplification, SNP genotyping, and GEBV prediction. The workflow provides a technical foundation for applying EGS in pig breeding and has the potential to accelerate genetic improvement through early embryo selection. Additionally, the results demonstrate that SCNT can be used to replicate elite genetic resources for the pig farming industry.

Hantaviruses are increasingly regarded as an important emerging risk to global health, with an estimated annual impact on more than 200000 people worldwide. These pathogens are single-stranded RNA viruses belonging to the family Han taviridae and are known to cause two major clinical syndromes in humans: Hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). The so-called old world hantaviruses, which are associated with HFRS, are predominantly distributed across Asia, Europe, and parts of Africa. In contrast, new world hantaviruses, responsible for HPS, are largely confined to North and South America. Each year, approximately 150000-200000 HFRS cases require hospitalization globally, with the greatest burden occurring in developing regions. The mortality rate of HFRS ranges from below 1% to about 12%, depending on the infecting strain. Both disease forms are characterized by increased capillary permeability, leading to clinical features such as hypotension, thrombocytopenia, and leukocytosis. While HFRS has a broader geographic distribution, HPS carries a higher risk of death. Moreover, the detection of new viral strains and the steady rise in reported cases have intensified global concern. Enhancing surveillance systems and expanding laboratory diagnostic capacity are therefore essential for effective monitoring and control of hantavirus diseases.

The Junin virus (JUNV) is mainly perpetuated in nature by rodent reservoirs, especially Calomys musculinus, and is transmitted to humans through aerosolization of contaminated rodent excreta. Clinical presentation of Argentine haemorrhagic fever (AHF) is characterized by an incubation period of about 7-14 days and several clinical manifestations such as fever, malaise, hematological abnormalities, hemorrhagic symptoms and neurological complications. The current review summarizes the current knowledge on the taxonomy, structure, genome structure, transmission dynamics, pathogenesis, clinical syndrome, and diagnostic methods that are related to JUNV infection. Special emphasis is on the progress in the sphere of molecular diagnostics, immune plasma therapy, and antiviral studies. The introduction of the Candid #1 live attenuated vaccine is a significant step towards the prevention of the AHF and has greatly reduced the prevalence of the disease among the endemic populations. Recent scientific advances, such as reverse genetics systems, genomic surveillance, and new therapeutic strategies, have added to the knowledge of the biology of JUNV and its interplay with the host immune system. Nonetheless, there are still challenges because of further spreading of the viruses among the rodents (reservoirs), inability to develop specific antiviral therapies, and the potential of other related arenaviruses. Argentine hemorrhagic fever needs to be prevented, diagnosed and controlled by further research, enhanced surveillance systems and enhanced vaccination.

Viral encephalitis requires rapid etiological assessment, yet targeted polymerase chain reaction, serology, culture, and multiplex panels leave many cases unresolved because they depend on prespecified pathogens, sampling time, and specimen biology. Metagenomic next-generation sequencing (mNGS) can interrogate DNA and RNA in cerebrospinal fluid without a predefined target and may detect unexpected, rare, opportunistic, or emerging viruses. Its clinical performance, however, is not uniform. In published cohorts, diagnostic yield varies with case selection, reference standards, pathogen burden, specimen volume, pretreatment, laboratory workflow, sequencing depth, bioinformatic thresholds, and contamination control. Short-read Illumina workflows currently have the largest clinical evidence base, whereas real-time nanopore sequencing offers speed and portability but still requires site-specific validation. The strongest role for mNGS is therefore not routine first-line replacement of polymerase chain reaction or serology, but early complementary use in severe, progressive, unexplained, atypical, or immunocompromised cases after urgent targeted testing and empirical treatment have begun. A positive result requires assessment of read distribution, genome coverage, controls, clinical plausibility, and orthogonal confirmation; a negative result cannot exclude a low-titer, serology-defined, or tissue-restricted infection. This minireview critically compares the available evidence, identifies causes of between-study variation, and proposes a practical decision pathway for integrating mNGS into the diagnosis of viral encephalitis.