An experiment was conducted to identify and characterize the circular RNA expression and metabolic characteristics in the liver of Jinhua pigs and Landrace pigs. Three Jinhua pigs and three Landrace pigs respectively at 70-day were slaughtered to collect the liver tissue samples. Immediately after slaughter, blood samples were taken to detect serum biochemical indicators. Total RNA extracted from liver tissue samples were used to prepare the library and then sequence on HiSeq 2500. Bioinformatic methods were employed to analyze sequence data to identify the circRNAs and predict the potential roles of differentially expressed circRNAs between the two breeds. Significant differences in physiological and biochemical traits were observed between growing Jinhua and Landrace pigs. We identified 84,864 circRNA candidates in two breeds and 366 circRNAs were detected as significantly differentially expressed. Their host genes are involved in lipid biosynthetic and metabolic processes according to the gene ontology analysis and associated with metabolic pathways. Our research represents the first description of circRNA profiles in the porcine liver from two divergent phenotype pigs. The predicted miRNA-circRNA interaction provides important basis for miRNA-circRNA relationships in the porcine liver. These data expand the repertories of porcine circRNA and are conducive to understanding the possible molecular mechanisms involved in miRNA and circRNA. Our study provides basic data for further research of the biological functions of circRNAs in the porcine liver.

This study was to investigate the correlations of myogenic differentiation 1 (MYOD1) gene polymorphisms with carcass traits and its expression with breast muscle development in pigeons. Four SNPs were found in the pigeon MYOD1 gene. Correlation analysis showed that individuals with AA genotype at both SNPs g.2967A > G (p < .01) and g.3044G > A (p < .05) have significantly higher live weight (LW), carcass weight (CW), semi-eviscerated weight (SEW), eviscerated weight (EW) and breast muscle weight (BMW). Moreover, the two SNPs also had the same significant effects on MYOD1 mRNA expression levels in breast muscle of pigeons, ie, the AA genotype showed higher MYOD1 mRNA expression levels. The diameter and cross-section area of muscle fibers continuously increased from 0w to 4w (p < .05), accompanied with the increasing expression of MYOD1 gene, while the density decreased (p < .05) dramatically from 0w to 1w and continuously fell over in the next few weeks (p > .05). What's more, the expression level of MYOD1 gene was positively correlated with a diameter (r = 0.937, p < .05) and cross-sectional area (r = 0.956, p < .01) of myofiber, and negatively correlated with density (r = -0.769, p < .01). The results showed that individuals with AA genotype at both SNPs g.2967A > G and g.3044G > A have showed higher carcass traits (LW, CW, SEW, EW, and BMW) and higher MYOD1 mRNA expression level in breast muscle than AB and BB genotypes. Moreover, the expression level of MYOD1 gene was closely correlated with muscle characteristic traits, indicating variants of MYOD1 gene was closely related to muscle development and could be a potential candidate gene in marker-assisted selection of pigeons.

The 23-valent pneumococcal vaccine (PPV23) is a classical common vaccine used to prevent pneumococcal disease. In past decades, it was thought that vaccination with this vaccine induces humoral immunity, thereby reducing the disease associated with infection with 23 common serotypes of Streptococcus pneumoniae (Sp). However, for this polysaccharide vaccine, the mechanism of immune response at the transcriptional level has not been fully studied. To identify the lncRNAs (long noncoding RNAs) and mRNAs in spleens related to immunity after PPV23 vaccination in mice, high-throughput RNA sequencing of spleens between a PPV23 treatment group and a control group were performed and evaluated in this study. The RNA-seq results identified a total of 41,321 mRNAs and 34,375 lncRNAs, including 55 significantly differentially expressed (DE) mRNAs and 389 DE lncRNAs (p < 0.05) between the two groups. GO and KEGG annotation analysis indicated that the target genes of DE lncRNAs and DE mRNAs were related to T-cell costimulation, positive regulation of alpha–beta T-cell differentiation, the CD86 biosynthetic process, and the PI3K-Akt signaling pathway, indicating that the polysaccharide component antigens of PPV23 might activate a cellular immune response during the PPV23 immunization process. Moreover, we found that Trim35 (tripartite motif containing 35), a target gene of lncRNA MSTRG.9127, was involved in regulating immunity. Our study provides a catalog of lncRNAs and mRNAs associated with immune cells’ proliferation and differentiation, and they deserve further study to deepen the understanding of the biological processes in the regulation of PPV23 during humoral immunity and cellular immunity.

The Group ACYW135 meningococcal polysaccharide vaccine (MPV-ACYW135) is a classical common vaccine used to prevent Neisseria meningitidis serogroups A, C, Y, and W135, but studies on the vaccine at the transcriptional level are still limited. In the present study, mRNAs and lncRNAs related to immunity were screened from the spleens of mice inoculated with MPV-ACYW135 and compared with the control group to identify differentially expressed mRNAs and lncRNAs in the immune response. The result revealed 34375 lncRNAs and 41321 mRNAs, including 405 differentially expressed (DE) lncRNAs and 52 DE mRNAs between the MPV group and the control group. Results of GO and KEGG enrichment analysis turned out that the main pathways related to the immunity of target genes of those DE mRNAs and DE lncRNAs were largely associated with positive regulation of T cell activation, CD8-positive immunoglobulin production in mucosal tissue, alpha-beta T cell proliferation, negative regulation of CD4-positive, and negative regulation of interleukin-17 production, suggesting that the antigens of MPV-ACYW135 capsular polysaccharide might activate T cell related immune reaction in the vaccine inoculation. In addition, it was noted that Bach2 (BTB and CNC homolog 2), the target gene of lncRNA MSTRG.17645, was involved in the regulation of immune response in MPV-ACYW135 vaccination. This study provided a preliminary catalog of both mRNAs and lncRNAs associated with the proliferation and differentiation of body immune cells, which was worthy of further research to enhance the understanding of the biological immune process regulated by MPV-ACYW135.

Editorial: Reproduction-related non-coding RNAs in animals

This study investigated how Chinese bayberry leaves proanthocyanidins (BLPs) regulate glucose and lipid metabolism through the gut microbiota-barrier axis. In high-fat diet (HFD)-induced obese mice, BLPs significantly reduced body weight, improved glucose tolerance, and alleviated dyslipidemia. BLPs remodeled the gut microbiota by reducing the Firmicutes/Bacteroidota ratio and enriching beneficial taxa, including Bifidobacterium and Dubosiella . BLPs also improved intestinal barrier function, as evidenced by increased Occludin and MUC2 expression, reduced serum lipopolysaccharide levels, and enhanced microbial metabolite production, including short-chain fatty acids and altered bile acid profiles. Furthermore, BLPs activated IRS1/PI3K/AKT and AMPK signaling pathways associated with glucose and lipid metabolism. Fecal microbiota transplantation further supported a contribution of the gut microbiota to the metabolic effects of BLPs. These findings provide mechanistic insights into the protective effects of BLPs against HFD-induced metabolic disorders and highlight their potential as functional food ingredients for metabolic health.