This study aimed to determine the effects of different dietary threonine levels on the antioxidant and immune capacity and the immunity of broilers. A total of 432 one-day-old Arbor Acres (AA) broilers were randomly assigned to 4 groups, each with 6 replicates of 18 broilers. The amount of dietary threonine in the four treatments reached 85%, 100%, 125%, and 150% of the NRC (Nutrient Requirements of Poultry, 1994) recommendation for broilers (marked as THR85, THR100, THR125, and THR150). After 42 days of feeding, the cecum contents and jejunum mucosa were collected for metabolic analysis and transcriptional sequencing. The results indicated that under the condition of regular and non-disease growth of broilers, compared with that of the THR85 and THR150 groups, the metabolic profile of the THR125 group was significantly higher than that of the standard requirement group. Compared with the THR100 group, the THR125 group improved antioxidant ability and immunity of broilers and enhanced the ability of resisting viruses. The antioxidant gene CAT was upregulated. PLCD1, which is involved in immune signal transduction and plays a role in cancer suppression, was also upregulated. Carcinogenic or indirect genes PKM2, ACY1, HK2, and TBXA2 were down-regulated. The genes GPT2, glude2, and G6PC, which played an important role in maintaining homeostasis, were up-regulated. Therefore, the present study suggests that 125% of the NRC recommendations for Thr level had better effects on antioxidant and immune capacity, as well as maintaining the homeostasis of the body.

MicroRNAs (miRNAs) play significant roles in mammalian spermatogenesis. Sertoli cells can provide a stable microenvironment and nutritional factors for germ cells, thus playing a vital role in spermatogenesis. However, few studies elucidate the regulation of bovine testicular Sertoli cells by miRNAs. Here, we have reported that miRNA-34c (miR-34c) regulates proliferation, apoptosis, and relative transcripts abundance gene in bovine Sertoli cells. In bovine Sertoli cells, overexpression of miR-34c inhibited proliferation and relative abundance of gene transcripts while promoting apoptosis of Sertoli cells, and the effects were the opposite when miR-34c was knocked down. Receptor tyrosine kinase (AXL) was identified as a direct target gene of miR-34c in Sertoli cells, validated by analysis of the relative abundance of AXL transcript and dual-luciferase reporter assay. The relative abundance of the transcript of genes related to male reproduction in Sertoli cells was changed after the AXL gene was overexpressed, as demonstrated by the RT2 Profiler PCR Array results. In summary, miR-34c specifically regulated the AXL gene by targeting a sequence in the 3'-UTR, which could influence proliferation, apoptosis, and relative abundance of the transcript of male reproduction-related genes. Therefore, miR-34c could be considered an essential regulator in the process of bull spermatogenesis.

This study aimed to investigate the effects of different levels of methionine hydroxyl analogue chelated zinc (MHA-Zn) on antioxidant capacity and liver metabolism of aged laying hens. A total of 960 57-week-old layers were fed a basal diet (Zn: 35.08 mg/kg) without extra zinc for two weeks, and then allocated to four treatments consisting of eight replicates of 30 birds each for 14 weeks. Four levels of Zn (zinc sulfate (ZnSO4): 80 mg/kg; MHA-Zn: 20, 40, 80 mg/kg) were added to the diet. The results indicated that compared with inorganic zinc, organic zinc of 80 mg/kg has a significant advantage in improving the antioxidant capacity of aged hens, which increased the level of Cu/Zn-superoxide dismutase (SOD) and the total antioxidant capacity (T-AOC) in the serum and liver, and reduced the concentration of malondialdehyde (MDA) of laying hens. The serum albumen composition was significantly modified, meanwhile, the level of total protein, globulin, and urea increased remarkably, whereas serum glutamic-oxaloacetic transaminase decreased notably in 80 mg/kg MHA-Zn groups. Compared with the 20 mg/kg MHA-Zn group, the metabolic profile of 40 and 80 mg/kg MHA-Zn groups was higher than that of the inorganic zinc group. Furthermore, integrated key metabolic pathway analysis showed that 40 and 80 mg/kg MHA-Zn groups participated in the regulation of glutathione metabolism, glycine, serine, and threonine metabolism. Therefore, this study suggests that 40 and 80 mg/kg supplementation of MHA-Zn can increase the activity of Cu/Zn-SOD and T-AOC and decrease MDA; additionally the 80 mg/kg MHA-Zn group has better antioxidant capacity. Meanwhile, the enhanced MHA-Zn promoted methionine (Met) synthesis and protein metabolism.

In this study, the complete mitochondrial genome sequence of one female Pingpu Yellow chicken (PYC) and the D-loop sequences obtained from 60 chickens were analyzed to investigate their genetic diversity and phylogeny. The total length of the PYC mitogenome is 16,785 bp and that of the complete D-loop is 1231 to 1232 bp. The mitogenome comprises 22 transfer ribonucleic acids (tRNAs), 2 ribosomal ribonucleic acids (rRNAs), 13 protein-coding genes (PCGs), and 1 non-coding control region (D-loop). Additionally, the total length of the 13 PCGs is 11,394 bp, accounting for 67.88% of the complete mitogenome sequence, and the PCGs region has 3798 codons. A majority of the PCGs have ATG as the start codon. The haplotype and nucleotide diversity of PYC were 1.00000 ± 0.00029 and 0.32678 ± 0.29756, respectively. In the D-Loop data set, we found 25 polymorphic sites, which determined 18 haplotypes and 3 major haplogroups (A-C). Therefore, PYC has a classical vertebrate mitogenome, with comparatively high nucleotide diversity and potentially three maternal lineages. The neighbor-joining (NJ) tree analysis results showed PYC grouped with the Luhua (MT555049.1) and Nandan chickens (KP269069.1), which indicates that PYC is closely related to these two breeds.

In this study, we precisely constructed and transfected the overexpression and interference vectors in BFFs to evaluate the role of DLK1 gene on lipid metabolism in vitro. The expression of of DLK1 in the mRNA and protein level tended to reduce, and TGs were significantly increased in the pGPU6-shDLK1 group compared to the control group (p < 0.05). The expression of DLK1 in the mRNA and protein level were increased in the pBI-CMV3-DLK1 group compared to the control group, and the TGs content showed a significant decrease in the pBI-CMV3-DLK1 group (p < 0.05). Meanwhile, we used the restriction fragment length polymorphism (RFLP-PCR) detection method to screen SNPs further to explore and analyze the relationship between the gene and the economic traits of 28-month-old Chinese Simmental and the fatty acids composition of cattle longissimus muscle. The result showed that two SNPs, IVS3 + 478 C>T and IVS3 + 609 T>G, were identified as being significantly associated with carcass and meat quality traits in Chinese Simmental, such as the carcass fat coverage rate, loin eye muscle area, and fat color score. In summary, our results indicated that DLK1 can affect lipid metabolism in bovine and these two SNPs might be applied as genetic markers of meat quality traits for beef cattle breeding.

To evaluate the ameliorative effect of algae-derived polysaccharide (ADP) supplementation on duodenal injury caused by heat stress (HS) in broilers, a total of 144 male yellow-feathered broilers (56-day-old) were randomly allocated into three groups: The TN group (thermoneutral zone, broilers were raised at 23.6 ± 1.8 °C); HS group (heat stress, broilers were exposed to 33.2 ± 1.5 °C 10 h/day, 8:00 a.m.-18:00 p.m., the temperature in the remaining period was consistent with the TN group); HSA group (heat-stressed broilers were fed with ADP supplemented diet at 1000 mg/kg). There were six replications in each treatment, and eight broilers in each replication. The feeding trial lasted four weeks. The results showed that dietary ADP supplementation tended to increase the villus height (p = 0.077) and villus width (p = 0.062), and decrease the apoptosis rate (p = 0.081) in the duodenum of broilers under HS. Furthermore, dietary ADP increased the relative mRNA and protein (based on immunofluorescence) expression levels of occludin and zonula occludens-1 (ZO-1) in the duodenum of broilers under HS (p < 0.05). In addition, dietary ADP enhanced the total antioxidation capacity (T-AOC) and activity of glutathione-S transferase (GST), while reducing the malondialdehyde (MDA) concentration of the duodenum in broilers under HS (p < 0.05). Moreover, dietary ADP supplementation upregulated the duodenal nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), glutathione peroxidase 1 (GPx1) and glutathione S-transferase theta 1 (GSTT1) mRNA expression levels in heat-stressed broilers (p < 0.05). Furthermore, compared with the HS group, broilers fed with an ADP supplemented diet had a higher relative mRNA expression of inhibitor kappa B alpha (IκBα) (p < 0.05) and a lower relative mRNA expression of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the duodenum (p < 0.05). In summary, dietary ADP supplementation had an ameliorative effect on HS-induced impairment of tight junctions, antioxidant capacity and the immune response of the duodenum in broilers. These beneficial effects might be related to the modulation of Nrf2 and NF-κB signaling pathways.

This study aims to screen potential regulators and regulate fecundity networks between microRNAs (miRNAs) and target genes. The bovine testes of immature and mature Chinese Red Steppes were performed by genome-wide analysis of mRNAs and miRNAs. Compared with testicular tissues of newborns, 6051 upregulated genes and 7104 downregulated genes in adult cattle were identified as differentially expressed genes (DEGs). The DEGs were significantly enriched in 808 GO terms (p < 0.05) including male gonad development, male genitalia development, spermatogenesis, and sperm motility. Moreover, DEGs were also significantly enriched in 105 KEGG pathways (p < 0.05), including cGMP-PKG signaling pathway and calcium signaling pathway. To explore the expression of miRNA-regulated gene expression, 896 differentially expressed target genes negatively regulated with the expression levels of 31 differentially expressed miRNAs (DERs) were predicted and analyzed, and a network-integrated analysis was constructed. Furthermore, real-time PCR was performed to verify the expression levels of DEGs and DERs. Our results identified novel candidate DEGs and DERs correlated with male reproduction and intricate regulating networks between miRNAs and genes, which will be valuable for future genetic and epigenetic studies of sperm development and maturity, as well as providing valuable insights into the molecular mechanisms of male fertility and spermatogenesis in cattle.