Geese evolved from migratory birds, and when they consume excessive high-energy feed, glucose is converted into triglycerides. A large amount of triglyceride deposition can induce incomplete oxidation of fatty acids, leading to lipid accumulation in the liver and the subsequent formation of fatty liver. In the Chaoshan region of Guangdong, China, Shitou geese develop a unique form of fatty liver through 24 h overfeeding of brown rice. To investigate the mechanisms underlying the formation of fatty liver in Shitou geese, we collected liver samples from normally fed and overfed geese. The results showed that the liver size in the treatment group was significantly larger, weighing 3.5 times more than that in the control group. Extensive infiltration of lipid droplets was observed in the liver upon staining of tissue sections. Biochemical analysis revealed that compared to the control group, the treatment group showed significantly elevated levels of total cholesterol (T-CHO), triglycerides (TG), and glycogen in the liver. However, no significant differences were observed in the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), which are common indicators of liver damage. Furthermore, we performed a combined transcriptomic and lipidomic analysis of the liver samples and identified 1,510 differentially expressed genes (DEGs) and 1,559 significantly differentially abundant metabolites (SDMs). The enrichment analysis of the DEGs revealed their enrichment in metabolic pathways, cellular process-related signaling pathways, and specific lipid metabolism pathways. We also conducted KEGG enrichment analysis of the SDMs and compared them with the enriched signaling pathways obtained from the DEGs. In this study, we identified 3 key signaling pathways involved in the formation of fatty liver in Shitou geese, namely, the biosynthesis of unsaturated fatty acids, glycerol lipid metabolism, and glycerophospholipid metabolism. In these pathways, genes such as glycerol-3-phosphate acyltransferase, mitochondrial (GPAM), 1-acylglycerol-3-phosphate O-acyltransferase 2 (AGPAT2), diacylglycerol O-acyltransferase 2 (DGAT2), lipase, endothelial (LIPG), lipoprotein lipase (LPL), phospholipase D family member 4 (PLD4), and phospholipase A2 group IVF (PLA2G4F) may regulate the synthesis of metabolites, including triacylglycerol (TG), phosphatidate (PA), 1,2-diglyceride (DG), phosphatidylethanolamine (PE), and phosphatidylcholine (PC). These genes and metabolites may play a predominant role in the development of fatty liver, ultimately promoting the accumulation of TG in the liver and leading to the progression of fatty liver.

Lipopolysaccharide (LPS) can affect the immune system of geese by inducing liver injury. The polysaccharide of Atractylodes macrocephala Koidz (PAMK) have obvious immune-enhancing effects. Accordingly, this experiment investigated the effect of PAMK on LPS-induced liver injury in goslings. Two hundred 1-day-old goslings were randomly divided into the control group, LPS group, PAMK group, and PAMK+ LPS group, and the PAMK and PAMK+ LPS groups were fed the basal diet with 400 mg/kg PAMK, while the control and LPS groups were fed the basal diet. On D 21, 23, and 25 of the formal trial, the goslings in the LPS and PAMK+LPS groups were injected intraperitoneally with 2 mg/kg LPS, and goslings in the control and PAMK groups were injected intraperitoneally with the same amount of saline. Livers were collected on D 25. HE-stained sections showed that PAMK could effectively alleviate the LPS-induced indistinct hepatic cord structure, loss of cytoplasmic contents of hepatocytes, and dilatation of hepatic sinusoids. The biochemical parameters of liver tissues showed that PAMK could alleviate the LPS-induced upregulation of alanine aminotransferase and aspartate aminotransferase. To further investigate the mechanism of the mitigating effect of PAMK on LPS-induced injury, livers from the LPS and PAMK+LPS groups were selected for transcriptome sequencing. The sequencing results showed that there were 406 differentially expressed genes (DEGs) in the livers of LPS and PAMK+LPS goslings, of which 242 upregulated and 164 downregulated. The Kyoto Encyclopedia of Genes and Genome (KEGG) analysis showed that DEGs were significantly enriched in immune signal transduction, cell cycle, and cell metabolism. Besides, protein‒protein interaction analysis showed that 129 DEGs were associated with each other, including 7 DEGs enriched in the p53 and FOXO signaling pathway. In conclusion, PAMK may alleviate LPS-induced liver injury in gosling through the p53 and FOXO signaling pathway. These results provide a basis for further development of PAMK as an immunomodulator.

Lipopolysaccharide (LPS) is one of the main virulence factors of Gram-negative bacteria. In the process of waterfowl breeding, an inflammatory reaction due to LPS infection is easily produced, which leads to a decline in waterfowl performance. The liver plays a vital role in the immune response and the removal of toxic components. Therefore, it is necessary to study the mechanism of liver injury induced by LPS in goose. In this study, a total of 100 1-day-old goslings were randomly divided into a control group and LPS group after 3 days of pre-feeding. On days 21, 23, and 25 of the formal experiment, the control group was intraperitoneally injected with 0.5 mL normal saline, and the LPS group was intraperitoneally injected with LPS 2 mg/(kg body weight) once a day. On day 25 of the experiment, liver samples were collected 3 h after the injection of saline and LPS. The results of histopathology and biochemical indexes showed that the livers of the LPS group had liver morphological structure destruction and inflammatory cell infiltration, and the levels of ALT and AST were increased. Next, RNA sequencing analysis was used to determine the abundances and characteristics of the transcripts, as well as the associated somatic mutations and alternative splicing. We screened 727 differentially expressed genes (DEGs) with p < 0.05 and |log₂(Fold Change)| ≥ 1, as the thresholds; GO and KEGG enrichment analysis showed that LPS-induced liver injury may be involved in the Toll-like receptor signaling pathway, MAPK signaling pathway, NOD-like receptor signaling pathway, FoxO, and PPAR signaling pathway. Finally, we intersected the genes enriched in the key pathway of LPS-induced liver injury with the top 50 key genes in protein–protein interaction networks to obtain 28 more critical genes. Among them, 17 genes were enriched in Toll-like signaling pathway and MAPK signaling pathway. Therefore, these results suggest that LPS-induced liver injury in geese may be the result of the joint action of Toll-like receptor, MAPK, NOD-like receptor, FoxO, and PPAR signaling pathway. Among them, the TLR7-mediated MAPK signaling pathway plays a major role.

Skeletal muscle is a critical component of goose meat and a significant economic trait of geese. The regulatory roles of miRNAs and lncRNAs in the maturation stage of goose skeletal muscle are still unclear. Therefore, this study conducted experiments on the leg muscles of Magang geese at two stages: 3-day post-hatch (P3) and 3 months (M3). Morphological observations revealed that from P3 to M3, muscle fibers mainly underwent hypertrophy and maturation. The muscle fibers became thicker, nuclear density decreased, and nuclei moved towards the fiber edges. Additionally, this study analyzed the expression profiles of lncRNAs, miRNAs, and mRNAs during the skeletal muscle fiber maturation stage, identifying 1,949 differentially expressed mRNAs (DEMs), 21 differentially expressed miRNAs (DEMIs), and 172 differentially expressed lncRNAs (DELs). Furthermore, we performed enrichment analyses on DEMs, cis-regulatory genes of DELs, and target DEMs of DEMIs, revealing significant enrichment of signaling pathways including MAPK, PPAR, and mTOR signaling pathways. Among these, the MAPK signaling pathway was the only pathway enriched across all three types of differentially expressed RNAs, indicating its potentially more significant role in skeletal muscle maturation. Finally, this study integrated the targeting relationships between DELs, DEMs, and DEMIs from these two stages to construct a ceRNA regulatory network. These findings unveil the potential functions and mechanisms of lncRNAs and miRNAs in the growth and development of goose skeletal muscle and provide valuable references for further exploration of the mechanism underlying the maturation of Magang geese leg muscle.

The bursa of Fabricius (BF) plays crucial roles in the goslings’ immune system. During waterfowl breeding, the presence of lipopolysaccharides (LPSs) in the environment can induce inflammatory damage in geese. Polysaccharides of Atractylodes macrocephala Koidz (PAMKs), as the main active component of the Chinese medicine Atractylodes macrocephala, have significant immune-enhancing effects. Accordingly, this study intended to investigate the effect of PAMKs on LPS-induced BF injury in goslings. Two hundred 1-day-old goslings (half male and half female) were selected and randomly divided into control, PAMK, LPS, and PAMK + LPS groups. The control and LPS groups were fed the basal diet, and the PAMK and PAMK + LPS groups were fed the basal diet containing PAMKs at 400 mg/kg. The goslings in the LPS and PAMK + LPS groups were injected intraperitoneally with LPS at a concentration of 2 mg/kg on days 24, 26, and 28 of this study. The control and PAMK groups were injected with equal amounts of saline. On the 28th day, 1 h after the LPS injection, the BF and serum were collected and analyzed for organ indices, cytokines, antioxidant indicators, and histological observations. Histological examination and HE staining demonstrated that the PAMK treatment ameliorated the LPS-induced BF atrophy, structural damage, increased cellular exudation, and reticulocyte hyperplasia in the goslings. The cytokine and antioxidant marker analyses in the BF cells demonstrated that the PAMK treatment mitigated the LPS-induced increase in the interleukin-1β (IL-1β), malondialdehyde (MDA), and inducible nitric oxide synthase (iNOS) levels, as well as the decrease in the transforming growth factor-β (TGF-β) and superoxide dismutase (SOD) activities. Further transcriptome sequencing identified a total of 373 differentially expressed genes (DEGs) between the LPS and PAMK + LPS groups. The KEGG enrichment pathway analysis showed that the DEGs were significantly enriched in the Toll-like receptor, p53, MAPK, GnRH, and ErbB signaling pathways. Among them, EREG played key roles in the activation of the MAPK, GnRH, and ErbB signaling pathways. Further research showed that the addition of PAMKs significantly inhibited the LPS-induced EREG expression, increased the cell viability, promoted the cell cycle entry into the S and G2 phases, and inhibited apoptosis. Meanwhile, PAMKs can reduce the protein expression of p-JNKs and c-FOS by inhibiting EREG. In summary, this study found that PAMKs could alleviate LPS-induced BF injury in goslings by inhibiting the expression of EREG.

Involution of the bursa of Fabricius (BF) with increasing age in avian species leads to decreases in lymphocyte counts and pathogen recognition, thereby compromising immune function and increasing susceptibility to infections. Polysaccharides of Atractylodes macrocephala Koidz (PAMK), a major component of the traditional Chinese medicine Atractylodes macrocephala, increase immunity. This study aimed to explore the impact of PAMK on the BF during involution in Magang geese. Following the prefeeding period, 54 four-month-old Magang geese were selected for the experiment. These geese were evenly divided into three groups. Each group consisted of three replicates, with six geese per replicate. One group was immediately euthanized to collect serum and BF samples. The remaining 36 geese were further divided into two groups: one group was maintained on a standard diet, and the other group was provided a diet supplemented with 400 mg/kg PAMK. One month later, serum and BF samples were collected for analysis. Morphological, organ index and histological observations indicate that PAMK can alleviate the significant reduction in the organ index of the BF during the involution process in Magang geese and mitigate the disorder of follicular arrangement and the decrease in the ratio of the cortical area to the medullary area in the BF. Immunoglobulin and oxidative stress results revealed that PAMK can increase the levels of immunoglobulins and reduce oxidative stress in involuting Magang geese. Functional enrichment analysis revealed that the Wnt signaling pathway plays a significant role in alleviating the involution of the BF in Magang geese. Further cellular studies revealed that the addition of PAMK inhibited apoptosis and promoted cell cycle progression into the S and G2 phases. In summary, PAMK effectively mitigates the involution of the BF in Magang geese by inhibiting the Wnt signaling pathway, thereby enhancing humoral immunity and improving antioxidant status.