The conversion of various non-sugar substances, such as propionate and lactate, produced by rumen microbial fermentation into glucose by hepatic gluconeogenesis is the main way to ensure an adequate supply of glucose to the mammary gland of ruminants. Unlike monogastric animals, in ruminants, hepatic gluconeogenesis is a continuous and efficient physiological process. Some signaling pathways, transcription factors, and nutrients affect the expression of genes encoding for gluconeogenic rate-limiting enzymes, which in turn are involved in the regulation of hepatic gluconeogenesis. Although hepatic gluconeogenesis in ruminants has been researched for decades, it still needs to be clarified in depth. Therefore, this review summarizes the process, substrates, and regulatory mechanisms of hepatic gluconeogenesis in ruminants and establishes a theoretical basis for the development of precise nutritional regulation strategies to facilitate high-quality high-efficiency lactation. According to the research so far, phosphoenolpyruvate carboxy kinase, fructose-1,6-bisphosphatase, and glucose-6-phosphatase have been highlighted as the main rate-limiting enzymes that determine the efficiency of gluconeogenesis. With regard to the underlying mechanisms, protein kinase A, protein kinase B, adenosine 5′-monophosphate kinase, and mammalian target of rapamycin pathways have been found to regulate the expression of key gluconeogenic genes through transcription factors. Further, supplementation with propionate, certain amino acids, and micronutrients has shown beneficial effects in terms of improving efficiency of gluconeogenesis. Given the complexity of the metabolic pathways involved in hepatic gluconeogenesis in periparturient ruminants, further research is warranted on the regulatory mechanisms involved and the effects of supplementation with various nutrients on milk yield and animal health.
The intestinal tract is the main place for animals to digest food and absorb nutrients, which also serves as the first line of defense against pathogens that invade the internal environment. Therefore, normal intestinal structure and function are essential for animal health. Poultry coccidiosis is an intestinal disease primarily caused by the parasitization of intestinal epithelial cells by protozoa of the genus Eimeria. The occurrence of coccidiosis not only compromises the intestinal integrity of poultry but also increases their disease susceptibility, thus posing a serious threat to the overall health and productivity of poultry. Nowadays, the primary methods for controlling and preventing coccidiosis in poultry are anticoccidial drugs or live oocyst vaccines. However, the use of the former may be associated with problems of resistance and drug residues, while the use of the latter may cause intestinal damage and significantly increase farming costs. For these reasons, it is critical to investigate green, safe, and cost-effective natural alternative strategies such as phytochemicals and probiotics for controlling coccidiosis as well as mitigating the deleterious effects of coccidial infections in production. In this review, we aim to summarize the role, mechanisms, and therapeutic potential of natural products in the treatment of coccidiosis to lay a theoretical foundation for effective coccidiosis control.
Meiotic recombination is key for genetic diversity, but its dynamics are underexplored in small inbred beef cattle populations. This study examines recombination in closed beef cattle populations and identifies related genomic regions. Using genotypic data from 1020 Line 1 Hereford and 3420 Composite Gene Combination (CGC) cattle, recombination rates were estimated through offspring and progenitor haplotypes. The CGC composite displayed a higher recombination rate (27.24 events) than the Line 1 population (26.38 events), with reduced rates in Line 1 potentially due to extended homozygous segments. Recombination varied by autosome length, increasing with longer autosomes. A genome-wide association study revealed novel genomic regions associated with recombination: significantly associated SNP markers were found on Bos taurus autosome (BTA) 1, 7, 13, 15, and 19 in the Line 1 population, and numerous others in the CGC population, indicating complex polygenic influences.
Tribbles pseudokinase 3 (TRIB3) interacts with a variety of proteins and plays a key role in the regulation of glucose metabolism and glycolysis in nonruminants, but whether it has a specific role in goat mammary lipid metabolism has still been kept unknown. In this study, we observed that TRIB3 is highly expressed in the mammary tissues of lactating dairy goats. Overexpressing TRIB3 in goat mammary epithelial cells (GMECs) suppressed the mRNA expression of GPAM, DGAT1, and PLIN1, which are associated with the formation of triacylglycerol and lipid droplets (p < 0.05). The fatty acid-sensitive transcription regulator PPARG was also downregulated. Interfering TRIB3 had the opposite effect and decreased Akt phosphorylation. The TRIB3 gene influenced fatty acid composition in GMECs, and its overexpression reduced the total concentration of intracellular triacylglycerol (p < 0.01), this response was verified using BODIPY staining. Overall, these data indicated that TRIB3 suppresses milk fatty acids metabolism through inhibiting p-AKT/PPARG signaling in GMECs.
Adoption of microbial preparations is becoming more and more prevalent in the pig breeding industry. Digestive tract microbes are recognized as crucial elements affecting physical characteristics of pigs. Until now, it is still challenging to establish connections between colonic microbiome and the host. In this study, weight gain models were created for Min and Yorkshire pigs. The colonic contents and colonic tissues were collected from two pig purebred strains (n = 8/group) with similar weights for multi-omics analysis. By difference analysis of colonic microbiota, Min pigs observed a significantly higher relative abundance of Bacteroides, Phocaeicola, Roseburia, and Parabacteroides, and Yorkshire pigs had a strongly higher relative abundance of Streptococcus, Vescimonas, Ligilactobacillus, and Lactococcus. Functional annotation showed that the colonic microbiota of Min pigs had extensive dietary polysaccharide and immunomodulatory capacity. Through the correlation analysis of colonic microbiota with metabolomics of colonic content or transcriptomics of colonic tissues, we provided direct and indirect relationships of microorganisms and hosts. By verification, the contents of Occludin, ZO-1, and pIgR in colonic tissue and sIgA, sIgG, and sIgM in colonic contents of Min pigs were significantly higher than that in Yorkshire pigs. This study revealed characteristics and functions of the colonic microbiota in Min and Yorkshire pigs and analyzed their interactions with the host. Also, we identified immune-related microorganisms. These results provided a theoretical basis for understanding the influence of colonic microbiota on phenotype shaping in pigs.
Understanding differences in chromatin state and changes in gene regulatory landscape of placode (Pc) and dermal condensate are crucial for decoding hair follicle (HF) morphogenesis programs. To identify cell-type-specific chromatin accessibility patterns in the developing HF, we integrated chromatin accessibility and transcriptome profiles at single-cell resolution during the murine HF induction stage. We applied unbiased analyses to identify seven major HF cell types and reclustered dermal (Der) and epithelium (Epi) subtypes to trace their cell fate specification. Our analysis showed that gene regulation in Der and Epi lineages is largely determined by cis-regulatory elements that direct gene expression in response to specific developmental cues. The chromatin accessibility of Twist2, Enpp2, Dkk1, and Sox2 varied from fibroblasts (Fb) to pre-DC lineage, while that of Edar, Lhx2, and Wnt10b varied from Epi to Pc lineage. Cell-type-specific enrichment of transcription factor binding motifs implicated Twist2 and Nfatc4 as key regulators in Fb to pre-DC fate specification, and Fos, Bach1, and Klf1 in Epi to Pc niche fate specification. Additionally, alignment of cell-type-specific peaks to super-enhancer databases identified key regulatory elements in both lineages. We identified and validated the critical cis-regulatory elements in pre-DC and Pc fate specifications through embryonic dorsal skin culture in vitro, suggesting that these elements may regulate critical genes essential for HF induction. Overall, our results provide a foundation for a comprehensive analysis of gene regulatory programs that initiate HF development, offering insights into the molecular mechanism of HF morphogenesis and clinical treatments of alopecia by skin grafts.
Wool curvature is one of the most valuable characteristics of Zhongwei goat fur. As the goats grow, the curvature progressively diminishes, which has a substantial impact on the quality and market value of wool. Circular RNAs (circRNAs) are a class of noncoding RNA and play vital roles in animal growth and development. However, the expression and function of circRNAs in the wool curvature of Zhongwei goats are unclear. In our study, we conducted circRNA expression profiling of Zhongwei goat skin exhibiting divergent curvature wool phenotypes at two developmental stages using the RNA-seq. In total, 12,682 circRNAs and 158 differentially expressed circRNAs (DE circRNAs) were identified. KEGG analysis illustrated that host genes of DE circRNAs were significantly enriched in the signaling pathways of Ras, JAK/STAT5, and cAMP, which might affect wool curvature. We further validated five circRNAs using qRT-PCR, which were consistent with the sequencing results. Functional verification assay demonstrated that circRNA8782 regulated fibroblast proliferation. In addition, we constructed a regulatory competing endogenous RNA (ceRNA) network and predicted circRNA3173-miR-16b-5p-IGF1 axes involved in the regulation of wool curvature. Our result will provide the foundation for uncovering the regulatory mechanisms of underlying wool curvature patterns in goats.
Growth traits are critical economic traits in sheep. Genetic polymorphism has a great influence on the improvement of sheep traits. The aim of this study was to analyze the effect of cadherin 18 (CDH18) gene polymorphisms on growth traits in Hu sheep. The single nucleotide polymorphisms (SNPs) of the CDH18 gene in Hu sheep were identified by Illumina Ovine SNP 50K BeadChip. Five SNPs were screened out within the CDH18 gene, where SNP1 (rs423955510) was located in exon and SNP2 (rs412944692), SNP3 (rs416959317), SNP4 (rs398980439) and SNP5 (rs428685044) were located in intron. The expression of the CDH18 gene in Hu sheep tissue was analyzed using quantitative real-time polymerase chain reaction, and the structure and phylogeny of the gene were analyzed using bioinformatics techniques. The results showed that SNP1, SNP2, SNP4, and SNP5 were significantly associated with body weight and body size (p < 0.05). Meanwhile, there were strong linkage disequilibrium relationships between SNP1 and SNP2 (r2 > 0.33). The CDH18 gene was expressed in the muscle tissues of Hu sheep at different months. The relative expression levels at weaning and 4-month muscle tissue were higher. Bioinformatic analysis revealed that SNP1 existed in the 5′ untranslated regions, which might affect the efficiency of translation. The above findings suggested that these SNP loci might affect growth traits and could be regarded as potential molecular markers for improving the growth performance of Hu sheep, which lay a molecular foundation for the breeding of sheep and accelerate the pace of sheep breeding.