Production of pimpled or sandpaper-shelled eggs (SE) is a major problem in aged hens. Probiotics can improve eggshell quality; however, the relationship between SE production and gut bacteria remains unclear. Here, 1200 450-d-old Hy-line hens were assigned to four groups (300 hens each), with the control group fed basal diet and treatment groups fed basal diet plus 500, 1000, and 1500 mg/kg of Clostridium butyricum and Bacillus subtilis, respectively. After 4 weeks, probiotics significantly decreased the SE rate from 42.51% to 28.02%. To address why probiotics reduced SE rate, the hens that only produced normal eggs (NE) or SE based on a 2-week assessment were assigned to three groups (NE, SE, and SEP groups; 10 hens each), with the NE and SE groups fed a basal diet and SEP group fed a basal diet plus 1000 mg/kg probiotics. After 4 weeks, ileal tissues from eight birds/group were collected for histomorphological and gene expression analyses, and the ileal content was collected from five birds/group for 16S rDNA sequencing analysis. The data showed that probiotics significantly increased the villus length and ratio of villus length to crypt depth. Quantitative PCR analysis indicated that there were no significant differences in the expression of genes related to tight junctions, nutrient transport, and calcium absorption among the groups (except TRPV6, P < 0.001). The 16S rDNA sequencing analysis indicated that the alpha-diversity of gut bacteria in the SEP group was the highest among the groups. The Firmicutes phylum was dominant in the NE and SEP groups, whereas the Proteobacteria phylum was dominant in the SE group. Together, these results suggest that probiotics can significantly influence A d v a n c e V i e w P r o o f s

No abstract

OTU deubiquitinase 7A (OTUD7A) can suppress inflammation signaling pathways, but it is unclear whether the gene can inhibit inflammation in goose fatty liver. In order to investigate the functions of OTUD7A and identify the genes and pathways subjected to the regulation of OTUD7A in the formation of goose fatty liver, we conducted transcriptomic analysis of cells, which revealed several genes related to inflammation and immunity that were significantly differentially expressed after OTUD7A overexpression. Moreover, the expression of interferon-induced protein with tetratricopeptide repeats 5 (IFIT5), tumor necrosis factor ligand superfamily member 8 (TNFSF8), sterile alpha motif domain-containing protein 9 (SAMD9), radical S-adenosyl methionine domain-containing protein 2 (RSAD2), interferon-induced GTP-binding protein Mx1 (MX1), and interferon-induced guanylate binding protein 1-like (GBP1) was inhibited by OTUD7A overexpression but induced by OTUD7A knockdown with small interfering RNA in goose hepatocytes. Furthermore, the mRNA expression of IFIT5, TNFSF8, SAMD9, RSAD2, MX1, and GBP1 was downregulated, whereas OTUD7A expression was upregulated in goose fatty liver after 12 days of overfeeding. In contrast, the expression patterns of these genes showed nearly the opposite trend after 24 days of overfeeding. Taken together, these findings indicate that OTUD7A regulates the expression of inflammation- and immune-related genes in the development of goose fatty liver.

Previous studies showed that insulin-like growth factor-binding protein 5 (IGFBP5) plays a role in non-alcoholic fatty liver disease; however, its expression and function in goose fatty liver remain unknown. To address this, we obtained a full-length mRNA sequence of the goose IGFBP5 gene using a 5′-rapid amplification of cDNA ends assay and nested polymerase chain reaction (PCR). Additionally, using the newly acquired sequence of 5’-untraslated region, we determined the missing sequence of the first intron. Bioinformatics analysis revealed three exons and three introns in the goose IGFBP5 gene. Quantitative PCR analysis indicated that the mRNA abundance of IGFBP5 was significantly lower in goose fatty liver than in the normal liver. Comparison of transcriptomes of goose primary hepatocytes transfected with IGFBP5 overexpression vector versus those transfected with empty vector identified 777 differentially expressed genes (DEGs). The enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways indicated the focal adhesion, ECM-receptor interaction, regulation of the actin cytoskeleton, mitogen-activated protein kinase (MAPK) signaling, and GnRH signaling pathways. Immunoblotting revealed the induction of the p38 MAPK pathway by IGFBP5 overexpression, which is in line with the suppressed expression of IGFBP5 and p38 MAPK in goose fatty liver than in normal liver. These findings suggest that IGFBP5 is involved in the development of goose fatty liver via the p38 MAPK pathway.