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.

The CD44 gene encodes a cell-surface glycoprotein that participates in a variety of biological processes such as cell interactions, adhesion, hematopoiesis, and tumor metastasis. We compared the transcriptome in bovine mammary epithelial cells (bMEC) of Chinese Holstein dairy cows producing milk of high and low fat contents. Our results suggest that CD44 might be a candidate gene affecting milk fat synthesis. In the present study, the overexpression of the CD44 gene increased the contents of intracellular triglycerides (TG) and cholesterol (CHOL), whereas knockdown of the CD44 gene decreased bMEC CHOL and TG contents. Gas chromatography analysis of fatty acid composition showed that the contents of α-linolenic acid, palmitic acid, and cis-8,11,14-eicosatrienoic acid were altered due to changes in the level of expression of the CD44 gene. Additionally, elaidic acid, palmitoleic acid, tridecanoic acid, and oleic acid were markedly reduced in the CD44 gene overexpression group compared with the control group. On the contrary, cis-5,8,11,14-eicosatetraenoic acid and stearic acid were markedly increased in the CD44 knockdown group compared with the control group. And RT2 Profiler PCR array (Qiagen, CLAB24070A Frankfurt, Germany) further suggested that overexpression or knockdown of the CD44 gene altered expression levels of functional genes associated with lipid metabolism. The present data indicate that CD44 plays a key regulatory role in lipid metabolism in bMEC.

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.

MicroRNAs (miRNAs) can regulate a variety of biological functions such as fat and cholesterol synthesis, translocation, and utilization by regulating degradation or by inhibiting target mRNA translation. In this study, the target gene of miR-21-3p was analyzed through bioinformatics, which predicted Elovl5 . Furthermore, miR-21-3p was verified for regulation of triglyceride expression. The results showed that luciferase activity was significantly lower in cells cotransfected with miR-21-3p and Elovl5 reporter vector, pmiR-RB-REPORT-Elovl5-WT , than in cells with miR-21-3p and reporter control vectors, pmiR-RB-REPORT-Elovl5-mut and pmiR-RB-REPORT-Elovl5-si , indicating that target sites exist in the 3′UTR of Elovl5 . Further analysis using qPCR and Western blotting showed that the expression of miR-21-3p negatively correlated with the levels of Elovl5 mRNA and protein, suggesting that miR-21-3p might play an important role in regulating Elovl5 gene expression. Finally, transfection with bta-miR-21-3p mimics , bta-miR-21-3p inhibitor , or miRNA-ShNC in mammary epithelial cells suggested that bta-miR-21-3p promotes triglyceride production, which might be attributed to the expression of the target gene Elovl5 .