Multiomics Reveals the Microbiota and Metabolites Associated with Sperm Quality in Rongchang Boars.

In this study, we investigated the correlation between the composition and function of the gut microbiota and the semen quality of Rongchang boars. Significant differences in gut microbial composition between boars with high (group H) and low (group L) semen utilization rates were identified through 16S rRNA gene sequencing, with 18 differential microbes observed at the genus level. Boars with lower semen utilization rates exhibited a higher relative abundance of Treponema, suggesting its potential role in reducing semen quality. Conversely, boars with higher semen utilization rates showed increased relative abundances of Terrisporobacter, Turicibacter, Stenotrophomonas, Clostridium sensu stricto 3, and Bifidobacterium, with Stenotrophomonas and Clostridium sensu stricto 3 showing a significant positive correlation with semen utilization rates. The metabolomic analyses revealed higher levels of gluconolactone, D-ribose, and 4-pyridoxic acid in the H group, with 4 pyridoxic acid and D-ribose showing a significant positive correlation with Terrisporobacter and Clostridium sensu stricto 3, respectively. In contrast, the L group showed elevated levels of D-erythrose-4-phosphate, which correlated negatively with Bifidobacterium and Clostridium sensu stricto 3. These differential metabolites were enriched in the pentose phosphate pathway, vitamin B6 metabolism, and antifolate resistance, potentially influencing semen quality. These findings provide new insights into the complex interplay between the gut microbiota and boar reproductive health and may offer important information for the discovery of disease biomarkers and reproductive health management.

[Effects and Mechanisms of Polystyrene Microplastics on Extracellular Antibiotic Resistance Genes in Wastewater].

Microplastics (MPs) and antibiotic resistance genes (ARGs) are typical co-existing emerging pollutants in wastewater treatment plants. MPs have been shown to alter the distribution pattern of ARGs in sludge, but their effects on free extracellular ARGs (feARGs) in wastewater remain unclear. In this study, we used fluorescence quantitative PCR to investigate the dynamics of feARGs (including tetC, tetO, sul1, and sul2) in wastewater and their transition mechanisms after 60 d of exposure to typical MPs (polystyrene, PS). The results showed that the absolute abundance of tetracycline feARGs decreased by 28.4 %-76.0 % and 35.2 %-96.2 %, respectively, under nm-level and mm-level PS exposure and changed by -55.4 %-122.4 % under µm-level PS exposure. The abundance of sul1 showed a trend of nm-level > µm-level > mm-level upon PS exposure, and the changes in sul1 abundance was greater with ρ(PS)=50 mg·L-1 exposure. The relative abundance of sul2 was reduced by 25.4 %-42.6 % and 46.1 %-90.3 % after µm-level and mm-level PS exposure, respectively, and increased by 1.9-3.9 times after nm-level PS exposure, and the sul2 showed a higher reduction at ρ (PS)=50 mg·L-1 exposure than that at ρ (PS)=0.5 mg·L-1. The Pearson correlation analysis showed that the relative abundance of feARGs during PS exposure was positively correlated with cell membrane permeability and typical mobile genetic elements (intI1) abundance and negatively correlated with reactive oxygen species level. Our findings elucidated the effects and corresponding mechanisms of PS on the growth and mobility of feARGs in wastewater, providing a scientific basis for the control of the combined MPs and ARGs pollution in wastewater.

A cell transcriptomic profile provides insights into adipocytes of porcine mammary gland across development.

BACKGROUND: Studying the composition and developmental mechanisms in mammary gland is crucial for healthy growth of newborns. The mammary gland is inherently heterogeneous, and its physiological function dependents on the gene expression of multiple cell types. Most studies focused on epithelial cells, disregarding the role of neighboring adipocytes. RESULTS: Here, we constructed the largest transcriptomic dataset of porcine mammary gland cells thus far. The dataset captured 126,829 high-quality nuclei from physiological mammary glands across five developmental stages (d 90 of gestation, G90; d 0 after lactation, L0; d 20 after lactation, L20; 2 d post natural involution, PI2; 7 d post natural involution, PI7). Seven cell types were identified, including epithelial cells, adipocytes, endothelial cells, fibroblasts cells, immune cells, myoepithelial cells and precursor cells. Our data indicate that mammary glands at different developmental stages have distinct phenotypic and transcriptional signatures. During late gestation (G90), the differentiation and proliferation of adipocytes were inhibited. Meanwhile, partly epithelial cells were completely differentiated. Pseudo-time analysis showed that epithelial cells undergo three stages to achieve lactation, including cellular differentiation, hormone sensing, and metabolic activation. During lactation (L0 and L20), adipocytes area accounts for less than 0.5% of mammary glands. To maintain their own survival, the adipocyte exhibited a poorly differentiated state and a proliferative capacity. Epithelial cells initiate lactation upon hormonal stimulation. After fulfilling lactation mission, their undergo physiological death under high intensity lactation. Interestingly, the physiological dead cells seem to be actively cleared by immune cells via CCL21-ACKR4 pathway. This biological process may be an important mechanism for maintaining homeostasis of the mammary gland. During natural involution (PI2 and PI7), epithelial cell populations dedifferentiate into mesenchymal stem cells to maintain the lactation potential of mammary glands for the next lactation cycle. CONCLUSION: The molecular mechanisms of dedifferentiation, proliferation and redifferentiation of adipocytes and epithelial cells were revealed from late pregnancy to natural involution. This cell transcriptomic profile constitutes an essential reference for future studies in the development and remodeling of the mammary gland at different stages.

Verapamil inhibits scar formation after peripheral nerve repair in vivo.

The calcium channel blocker, verapamil, has been shown to reduce scar formation by inhibiting fibroblast adhesion and proliferation in vitro. It was not clear whether topical application of verapamil after surgical repair of the nerve in vivo could inhibit the formation of excessive scar tissue. In this study, the right sciatic nerve of adult Sprague-Dawley rats was transected and sutured with No. 10-0 suture. The stoma was wrapped with gelfoam soaked with verapamil solution for 4 weeks. Compared with the control group (stoma wrapped with gelfoam soaked with physiological saline), the verapamil application inhibited the secretion of extracellular matrix from fibroblasts in vivo, suppressed type I and III collagen secretion and increased the total number of axons and the number of myelinated axons. These findings suggest that verapamil could reduce the formation of scar tissue and promote axon growth after peripheral nerve repair.