The Yili goose is the only indigenous goose breed that originates from Anser anser in China, known for its adaptability, strong flying ability, and tender meat with a low body lipid content. The liver plays a crucial role in lipid and glucose metabolism, including the intake, secretion, transportation, and storage of fatty acids (FAs). In this study, RNA-sequencing (RNA-seq) technology was performed to analyze the liver differentially expressed genes of Yili geese and their hybrid geese to investigate differences in liver lipid and glucose metabolism. A total of 452 differentially expressed genes (Q-value < 0.05) were identified. Notably, in KEGG enrichment analysis, four pathways (Q-value < 0.05) were enriched to be associated with lipid and glucose metabolism, including the metabolic pathway, PI3K–Akt signaling pathway, glycolysis/gluconeogenesis, and steroid biosynthesis. This study provides insights into potential candidate genes and metabolic pathways that affect the liver lipid metabolism of Yili goose. These findings provide a better understanding of animal liver lipid deposition and metabolism.

Transposable elements (TEs) play important roles in physiological processes, but their function in tail development remains poorly characterized. To explore their potential regulatory roles, we systematically analyzed the expression patterns of TEs during different fetal developmental stages of the sheep tail. Using RNA-seq data and the TEtranscripts pipeline, we identified differentially expressed TEs. Our key findings are as follows: (i) SINE/MIR, L1, and BovB elements exhibited significant stage-specific expression. (ii) The number of differentially expressed TEs was dynamic, with 2129 identified between stages E40–45 and E55–60, and 5554 between E55–60 and E70–75. (iii) These TEs were primarily located in intergenic regions, introns, and 3′UTRs, and their expression trends were highly consistent with those of adjacent differentially expressed genes. (iv) Pathway enrichment analysis revealed that TEs and their correlated genes between E40–45 and E55–60 were predominantly involved in tail elongation, while the comparison between E55–60 and E70–75 highlighted pathways related to tail fat formation. Furthermore, we identified specific candidate TEs associated with vertebra formation and fat deposition. This study provides novel insights into the role of TEs in shaping tail phenotypes and offers valuable information for sheep breeding programs.