Identification of potential candidate genes for the Huoyan trait in developing Wulong goose embryos by transcriptomic analysis.

1. The Wulong goose is a Chinese breed and a source of high-quality meat and eggs. A characteristic of the Wulong goose is that a proportion of the birds do not have eyelids, known as the Huoyon trait.2. Wulong geese exhibiting the Huoyan trait at embryonic stages of 9 days (E9), 12 days (E12) and 14 days (E14) were selected alongside those with normal eyelids for comprehensive transcriptome sequencing. Differentially expressed gene (DEG) and functional enrichment analyses were performed and finally, eight DEG were chosen to verify the accuracy of qPCR sequencing.3. Overall, 466, 962 and 550 DEG were obtained from the three control groups, D9 vs. N9, D12 vs. N12 and D14 vs. N14, respectively, by differential analysis (p < 0.05). CDKN1C, CRH, CROCC and TYSND1 were significantly expressed in the three groups. Enrichment analysis revealed the enrichment of CROCC and TYSND1 in pathways of cell cycle process, endocytosis, microtubule-based process, microtubule organising centre organisation, protein processing and protein maturation. CDKN1C and CRH were enriched in the cell cycle and cAMP signalling pathway.4. Some collagen family genes were detected among the DEGs, including COL3A1, COL4A5, COL4A2 and COL4A1. FREM1 and FREM2 genes were detected in both Huoyan and normal eyelids. There was a significant difference (p < 0.01) in FREM1 expression between ED9 and ED14 in female embryos, but this difference was not observed in male embryos.

Integrating genomics and transcriptomics to identify candidate genes for high egg production in Wulong geese (Anser cygnoides orientalis).

BACKGROUND: Wulong geese (Anser cygnoides orientalis) are known for their excellent egg-laying performance. However, they show considerable population differences in egg-laying behavior. This study combined genome-wide selection signal analysis with transcriptome analysis (RNA-seq) to identify the genes related to high egg production in Wulong geese. RESULTS: A total of 132 selected genomic regions were screened using genome-wide selection signal analysis, and 130 genes related to high egg production were annotated in these regions. These selected genes were enriched in pathways related to egg production, including oocyte meiosis, the estrogen signaling pathway, the oxytocin signaling pathway, and progesterone-mediated oocyte maturation. Furthermore, a total of 890 differentially expressed genes (DEGs), including 340 up-regulated and 550 down-regulated genes, were identified by RNA-seq. Two genes - GCG and FAP - were common to the list of selected genes and DEGs. A non-synonymous single nucleotide polymorphism was identified in an exon of FAP. CONCLUSIONS: Based on genome-wide selection signal analysis and transcriptome data, GCG and FAP were identified as candidate genes associated with high egg production in Wulong geese. These findings could promote the breeding of Wulong geese with high egg production abilities and provide a theoretical basis for exploring the mechanisms of reproductive regulation in poultry.

Effects of pantothenic acid on growth performance, slaughter performance, lipid metabolism, and antioxidant function of Wulong geese aged one to four weeks.

This experiment was conducted to study the effects of pantothenic acid on the growth performance, slaughter performance, lipid metabolism, and antioxidant function of one-to four-week-old Wulong geese and determine the appropriate supplemental level of pantothenic acid. A total of 360 one-day-old Wulong geese were randomly divided into 6 groups with 6 replicates per group and 10 geese (5 males and 5 females) per replicate. The geese in group Ⅰ (control group) were fed a basal diet, and the geese in groups Ⅱ to Ⅵ (experimental groups) were given the basal diet supplemented with 8, 15, 30, 60, and 120 mg/kg pantothenic acid, respectively. The experiment lasted for 4 weeks. Based on the results of unrelated comparative analysis, the body weight was the highest when the dietary pantothenic acid level was 27.57 mg/kg. When the dietary pantothenic acid level was 26.17 mg/kg, the average daily gain peaked. When the dietary pantothenic acid level was 15.50 mg/kg, the feed:gain ratio was the lowest. The percentage of abdominal fat in groups Ⅲ and Ⅳ was significantly lower than that in group Ⅰ (P < 0.05). The content of total cholesterol in serum in groups Ⅲ to Ⅴ was significantly lower than that in group Ⅰ (P < 0.05). The triglyceride content in groups Ⅲ and Ⅳ was significantly lower than that in group Ⅰ (P < 0.01). The high-density lipoprotein-cholesterol content in group Ⅳ was significantly higher than that in group Ⅰ (P < 0.05). The total antioxidant capacity of serum and liver in group Ⅳ was significantly higher than that in group Ⅰ (P < 0.05). The malondialdehyde content in the liver in groups Ⅲ and Ⅳ was significantly lower than that in group Ⅰ (P < 0.05). Glutathione peroxidase activity in the serum in group Ⅳ was significantly higher than that in group Ⅰ (P < 0.05). Glutathione peroxidase activity in the liver in groups Ⅳ and Ⅴ was significantly higher than that in group Ⅰ (P < 0.01). The addition of pantothenic acid in the diet of one-to four-week-old Wulong geese significantly affected the growth performance, slaughter performance, lipid metabolism, and antioxidant function of the geese. In terms of economic benefits, the optimal supplemental level of pantothenic acid in one-to four-week-old geese was 15.50 mg/kg.