Concurrent impacts of polystyrene nanoplastic exposure and Aeromonas hydrophila infection on oxidative stress, immune response and intestinal microbiota of grass carp (Ctenopharyngodon idella).

Research has demonstrated that polystyrene nanoplastics (PS-NPs) can have adverse effects on the immune responses of fish. NPs have the potential to increase the likelihood of infections in fish by pathogenic bacteria, such as the opportunistic pathogen Aeromonas hydrophila, potentially increasing the virulence of pathogenic bacteria infections in fish. The concurrent effects of PS-NPs and A. hydrophila on grass carp intestinal tissues were assessed by exposing grass carp to different concentrations of PS-NPs (10 µg/L, 100 µg/L, 1000 µg/L) after infection with A. hydrophila. As the concentration of PS-NPs in the exposure and the duration of A. hydrophila infection both escalated, intestinal tissues showed damage in the form of disordered breakage of intestinal villi, thinning of the intestinal wall, and reduced necrosis of the cells in the annulus muscle layer. The AHS-PS100 group and AHS-PS1000 group exhibited a substantial rise in the function of CAT, SOD, GST, and MPO, as well as increased MDA content and elevated ROS levels (p < 0.05). In the AHS-PS1000 group, the expression levels of IL-6, IL-8, IL-10, IL-1ß, TNF-α, and IFN-γ2 experienced a significant upsurge (p < 0.05). In addition, exposure to PS-NPs and A. hydrophila infection induced modifications in the microbial composition of the grass carp gut, affecting both phylum and genus taxonomic categories. Moreover, an increase in the abundance of Spirochaetota and Bacteroidota was observed not only in the positive control group but also in the AHS-PS100 and AHS-PS1000 groups following A. hydrophila infection. These experimental results indicate that PS-NPs exposure will aggravate the oxidative stress and inflammatory response of grass carp intestinal tissue in response to A. hydrophila infection, and lead to changes in intestinal microbial diversity and abundance. Overall, this study provides valuable hints on the potential concurrent effects of PS-NPs exposure on grass carp's response to A. hydrophila infection.

Global genetic diversity, introgression, and evolutionary adaptation of indicine cattle revealed by whole genome sequencing.

Indicine cattle, also referred to as zebu (Bos taurus indicus), play a central role in pastoral communities across a wide range of agro-ecosystems, from extremely hot semiarid regions to hot humid tropical regions. However, their adaptive genetic changes following their dispersal into East Asia from the Indian subcontinent have remained poorly documented. Here, we characterize their global genetic diversity using high-quality whole-genome sequencing data from 354 indicine cattle of 57 breeds/populations, including major indicine phylogeographic groups worldwide. We reveal their probable migration into East Asia was along a coastal route rather than inland routes and we detected introgression from other bovine species. Genomic regions carrying morphology-, immune-, and heat-tolerance-related genes underwent divergent selection according to Asian agro-ecologies. We identify distinct sets of loci that contain promising candidate variants for adaptation to hot semi-arid and hot humid tropical ecosystems. Our results indicate that the rapid and successful adaptation of East Asian indicine cattle to hot humid environments was promoted by localized introgression from banteng and/or gaur. Our findings provide insights into the history and environmental adaptation of indicine cattle.

Screening of linear B-cell epitopes and its proinflammatory activities of Haemophilus parasuis outer membrane protein P2.

Haemophilus parasuis is a commensal organism of the upper respiratory tract of pigs, but virulent strains can cause Glässer's disease, resulting in significant economic losses to the swine industry. OmpP2 is an outer membrane protein of this organism that shows considerable heterogeneity between virulent and non-virulent strains, with classification into genotypes I and II. It also acts as a dominant antigen and is involved in the inflammatory response. In this study, 32 monoclonal antibodies (mAbs) against recombinant OmpP2 (rOmpP2) of different genotypes were tested for reactivity to a panel of OmpP2 peptides. Nine linear B cell epitopes were screened, including five common genotype epitopes (Pt1a, Pt7/Pt7a, Pt9a, Pt17, and Pt19/Pt19a) and two groups of genotype-specific epitopes (Pt5 and Pt5-II, Pt11/Pt11a, and Pt11a-II). In addition, we used positive sera from mice and pigs to screen for five linear B-cell epitopes (Pt4, Pt14, Pt15, Pt21, and Pt22). After porcine alveolar macrophages (PAMs) were stimulated with overlapping OmpP2 peptides, we found that the epitope peptides Pt1 and Pt9, and the loop peptide Pt20 which was adjacent epitopes could all significantly upregulated the mRNA expression levels of IL-1α, IL-1ß, IL-6, IL-8, and TNF-α. Additionally, we identified epitope peptides Pt7, Pt11/Pt11a, Pt17, Pt19, and Pt21 and loop peptides Pt13 and Pt18 which adjacent epitopes could also upregulate the mRNA expression levels of most proinflammatory cytokines. This suggested that these peptides may be the virulence-related sites of the OmpP2 protein, with proinflammatory activity. Further study revealed differences in the mRNA expression levels of proinflammatory cytokines, including IL-1ß and IL-6, between genotype-specific epitopes, which may be responsible for pathogenic differences between different genotype strains. Here, we profiled a linear B-cell epitope map of the OmpP2 protein and preliminarily analyzed the proinflammatory activities and effects of these epitopes on bacterial virulence, providing a reliable theoretical basis for establishing a method to distinguish strain pathogenicity and to screen candidate peptides for subunit vaccines.

A SNP of the COX4I2 gene associated with environmental adaptation in Chinese cattle.

COX4I2 is an isoform of cytochrome C oxidase subunit IV (COX4), which plays an important role in mitochondrial oxidative phosphorylation. This gene affects heat production and thus affects thermoregulatory capacity in mammals. A splice region variant (rs109072064, NC_037340.1:g.61202988C > T) was identified in COX4I2 by using Ensembl, which transforms the amino acid arginine into cysteine in XP_005214921.1. In this study, we sought to determine the relationship between the mutant locus and the environment in which the cattle are located. We verified that mRNA (XM_005214864.4), which translated XP_005214921.1, is expressed in bovine muscle, fat, heart, liver, kidney, lung and testis tissues. The g.61202988C > T variant was then genotyped in 569 individuals of 34 cattle breeds. Compared with the CC genotype, southern cattle carried more the CT and TT genotypes. Furthermore, the association results carried out that the frequencies of genotypes (CC, CT, TT) and the value of climate parameters (mean annual temperature (T), relative humidity (RH) and temperature humidity index (THI)) were significantly correlated (P < 0.01). Hence, we speculated that the g.61202988C > T variant of COX4I2 gene was associated with the environmental adaptation trait in Chinese cattle and the locus may be considered as a molecular marker for Chinese cattle breeding.

The Expression Profiles of mRNAs and lncRNAs in Buffalo Muscle Stem Cells Driving Myogenic Differentiation.

Buffalo breeding has become an important branch of the beef cattle industry. Hence, it is of great significance to study buffalo meat production and meat quality. However, the expression profiles of mRNA and long non-coding RNAs (lncRNA) molecules in muscle stem cells (MuSCs) development in buffalo have not been explored fully. We, therefore, performed mRNA and lncRNA expression profiling analysis during the proliferation and differentiation phases of MuSCs in buffalo. The results showed that there were 4,820 differentially expressed genes as well as 12,227 mRNAs and 1,352 lncRNAs. These genes were shown to be enriched in essential biological processes such as cell cycle, p53 signaling pathway, RNA transport and calcium signaling pathway. We also identified a number of functionally important genes, such as MCMC4, SERDINE1, ISLR, LOC102394806, and LOC102403551, and found that interference with MYLPF expression significantly inhibited the differentiation of MuSCs. In conclusion, our research revealed the characteristics of mRNA and lncRNA expression during the differentiation of buffalo MuSCs. This study can be used as an important reference for the study of RNA regulation during muscle development in buffalo.

Promoter CpG methylation status in porcine Lyn is associated with its expression levels.

Resistance to disease and improvement of product quality are important goals in pig farming. Tyrosine Protein Kinase Lyn (LYN) is one of several Src-family tyrosine kinases in immune cells. This protein functions both as a positive and negative regulator of B cell activation, and regulates signaling pathways through phosphorylation of inhibitory receptors, enzymes and adaptors, which suggested that LYN could be correlated with immunity and can be considered as a candidate gene to study in disease resistance. Until now, the profiles of expression and transcriptional regulation of the LYN gene in pig breeds different in immune capacity remain unclear. Using real-time PCR, it indicated that porcine LYN mRNA expressed mainly in immune organs including the spleen, duodenum and liver. Furthermore, Dahuabai pigs (a kind of Chinese indigenous pig breeds with higher immune capacity) showed significant higher LYN mRNA expression levels than that in Landrace. Methylation analysis indicates that LYN expression levels were associated with the methylation status of the LYN promoter, and methylation of the novel CpG site at -1268C/-1267G generated by transposition at -1267 (A→G) results in up-regulating transcriptional activity of this gene. Interestingly, the base A located in -1267 mainly exhibited in landrace while the base G mainly in Dahuabai pigs. These results might contribute to study the function of this gene in pig breeding for disease resistance.

[Methylation status of pig adiponectin promoter and its expression].

Adiponectin, a cytokine hormone secreted exclusively by adipose tissue, has key roles in energy homeostasis and in metabolism of glucose and lipid. Adiponectin expression was negatively associated with obesity. Many CpG sites were found at the adiponectin promoter region (nucleotides -1500 approximately -1350 bp). To further understand the regulation of pig adiponectin expression, the methylation status of pig adiponectin promoter and its mRNA expression were analyzed by methylation special PCR (MSP) and real-time PCR. At the adiponectin promoter region where CG enriches (nucleotides -1500 approximately -1350 bp), the percentage of demethylation in Changbai pigs was 83%; and the percentages of demethylation in Lantang pigs at 90-day-old and adult stages were 33% and 100%, respectively. The process of methylation and demethyla-tion mainly occurred in certain CpG sites. In muscle tissues, the promoter hypermethylation status of adiponectin gene was detected, which was consistent with the expression of this gene. These results suggested that the methylation of this gene experienced a dynamic process, with the development of individuals, which agreed with the fluctuating trend of gene expression.