To investigate the regulatory mechanism of the competing endogenous RNAs (ceRNAs) on the egg performance of Gaoyou ducks, full transcriptome sequencing was performed to analyze the ovarian tissues in Gaoyou ducks. The ducks were categorized into high- and low-yield groups based on the individual in-cage egg production records and the hematoxylin–eosin (HE) staining results. The differentially expressed genes (DEGs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) were further processed by GO (gene ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses. In total, 72 DEmRNAs; 23 DElncRNAs; 4 DEcircRNAs; and 5 signaling pathways, including the ovarian steroidogenesis, PI3K-Akt, hedgehog, tryptophan metabolism, and oocyte meiosis signaling pathways, were significantly enriched. These results suggest that they could be associated with the Gaoyou duck’s ovarian function and affect the total egg production or double-yolked egg production. Furthermore, a coregulation network based on the related candidate ceRNAs across the high- and low-yield egg production groups was constructed. Our findings provide new insights into the mechanisms underlying the molecular regulation of related circRNA/lncRNA–miRNA–mRNA in the egg production and double-yolked egg traits of Gaoyou ducks.

The continuously evolving PRRSV has been plaguing pig farms worldwide for over 30 years, with conventional vaccines suffering from insufficient protection and biosecurity risks. To address these challenges, we identified 10 PRRSV-specific CTL epitopes through enzyme-linked immunospot assay (ELISPOT) and constructed a multi-epitope peptide (PTE) by linking them in tandem. This PTE was then fused with a modified porcine Fc molecule to create the recombinant protein pFc-PTE. Our findings indicate that pFc-PTE effectively stimulates PRRSV-infected specific splenic lymphocytes to secrete high levels of interferon-gamma (IFN-γ) and is predicted to be non-toxic and non-allergenic. Compared to PTE alone, pFc-PTE not only induced a comparable cellular immune response in mice but also extended the duration of the immune response to at least 10 weeks post-immunization. Additionally, pFc-PTE predominantly induced a Th1 immune response, suggesting its potential advantage in enhancing cellular immunity. Consequently, pFc-PTE holds promise as a novel, safe, and potent candidate vaccine for PRRSV and may also provide new perspectives for vaccine design against other viral diseases.

Pseudorabies virus (PRV) is a highly contagious pathogen in swine that can cross species barriers and infect other mammals, including humans. Given the potential for interspecies transmission and its threat to public health, understanding the molecular biology of PRV strains is essential for developing effective control measures and preparing for future pandemics. In this study, a novel PRV strain, PRV-HL-2021, was isolated from an outbreak in Heilongjiang Province, China. The viral genome was used to establish a reverse genetics system based on a fosmid library of the PRV-HL-2021 genome. This system facilitated the creation of recombinant PRV, including one expressing EGFP and another with deletions in the US9, gI, and gE genes. PRV-HL-2021 was found to be highly lethal to mice in vivo. The recombinant PRV strains, such as rPRV-US9-EGFP and rPRV-delgI/gE/US9, exhibited growth characteristics similar to the parental PRV-HL-2021 strain. The isolation and characterization of PRV-HL-2021 contribute to a better understanding of the genetic diversity of PRV strains. The developed reverse genetics system provides valuable tools for investigating viral functions, creating genetically modified PRV strains, and advancing the development of safer vaccines. These findings will enhance strategies for controlling PRV outbreaks and mitigating its impact on both animal and public health.

This study was conducted to investigate the effects of a Chinese herbal medicine compound microecological agent (C-MEA) on the egg production performance, ovarian follicle development, ovary transcriptome, and cecal microbiota of caged laying ducks. A total of 108 black Muscovy ducks (150 days old) were randomly divided into three groups for 30 days in a formal feeding trial. Compared with the control basic diet (Group C) and 16 g/kg C-MEA dosage (Group B), the 8 g/kg C-MEA dosage (Group A) increased egg production (average laying rate 69.35%) and follicle development (5~7 Fs, 6~7 LYFs, 11~13 SYFs) mass (p < 0.05). According to RNA-Seq, the ovaries’ transcriptome among different dietary groups enriched six key pathways, including neuroactive ligand–receptor interaction, the PPAR signaling pathway, ECM–receptor interaction, focal adhesion, the adherens junction, and the FoxO signaling pathway, as well as 46 candidate key genes. According to 16S-Seq, the microbial diversity was significantly increased in Group A, and the genus abundances of Sphaerochaeta and UCG-004 were significantly changed among different dietary groups (p < 0.05). Supplementation with C-MEA may optimize the cecal microflora and the interactions between the intestinal microflora and the host. The results from combining RNA-Seq and 16S-Seq demonstrated that the relationship between Sphaerochaeta and the hub gene cluster (F2, KNG1, C5, PLG, F2RL1, FABP1, and GCG) is the most prominent. In conclusion, the egg performance of caged laying ducks can be modulated through the microbiota–gut–ovary axis. Our findings provide new insights for improving gut health and reproductive performance of caged laying ducks.

As a high-value meat duck breed, Muscovy ducks exhibit marked individual differences in egg production that limit the economic efficiency of commercial farming. To elucidate the underlying mechanisms, we integrated phenotypic observation, ovarian transcriptome sequencing, and cecal 16S rRNA gene amplicon sequencing to compare high- and low-laying black-feathered Muscovy duck populations. We recorded 40-day egg production, assessed ovarian morphology, quantified gene expression profiles, and characterized microbial community structure. High-laying ducks produced significantly more eggs (24.60 ± 9.22) than low-laying ducks (15.80 ± 6.64, p < 0.01), with larger ovaries and a greater number of follicles at all developmental stages. Transcriptomic analysis revealed 823 DEGs, with KEGG enrichment implicating pathways governing ovarian physiology, including MAPK, Calcium, Notch, and Wnt signaling. Microbial profiling demonstrated significant differences in α/β diversity between groups, with high-laying ducks exhibiting an elevated Firmicutes/Bacteroidota ratio and decreased abundance of Ligilactobacillus. Integrative correlation analysis identified significant associations between Ligilactobacillus abundance and the expression of Arhgap27 and HOXA10, two genes linked to reproductive function, and highlighted the glycolysis/gluconeogenesis pathway as a convergently enriched signaling cascade shared between gut microbiome and ovarian transcriptome. This multi-omics study uncovers the molecular and microbial basis of egg production variation in Muscovy ducks, offering potential targets for improving breeding efficiency through microbiota-directed or gene-based interventions. These findings deepen our understanding of host–microbe interactions in poultry reproduction and identify candidate genes and microbial taxa that may serve as potential targets for future nutritional or genetic interventions to enhance laying performance in commercial duck production.

Semen quality is a critical determinant of male fertility in poultry, yet the testicular metabolic and molecular mechanisms underlying seminal traits in geese remain poorly understood. This study aimed to characterize the testicular metabolomic and transcriptomic profiles of Zhedong white geese with divergent semen quality, and to identify key regulatory pathways and candidate genes influencing semen quality. Untargeted metabolomics and RNA sequencing were performed on testicular tissues from geese with high (H) and low (L) semen quality. Serum hormone measurements revealed significantly increased testosterone (T) and decreased follicle-stimulating hormone (FSH) levels in the H group compared with the L group (p < 0.05). Metabolomic analysis identified 207 differential metabolites (DEMs), which were significantly enriched in glycosylphosphatidylinositol (GPI)-anchor biosynthesis, the citrate (TCA) cycle, and alanine, aspartate, and glutamate metabolism. Integrated transcriptomic and metabolomic analyses, combined with KEGG Markup Language (KGML) network analysis, revealed a candidate regulatory network involving potential metabolites (arachidonic acid, pyruvic acid, fumaric acid, malic acid and beta-alanine), signaling pathways (the citrate (TCA) cycle, arginine biosynthesis, ABC transporters, glycine/serine/threonine metabolism, and efferocytosis), and candidate genes (PLCB1, PLCB2, NT5C1A, TAT, LOC106042968 and ABCG8). Notably, PLCB1, which was significantly up-regulated in the H group, emerged as a candidate gene of particular interest that may be implicated in the regulation of metabolic pathways underlying semen quality in ganders. These findings provide novel insights into the testicular metabolic and transcriptomic determinants of semen quality in geese, and implicate PLCB1 and associated pathways as potential targets for improving male fertility in poultry.