Comparison of amino acid profiles and metabolic gene expression in muskrat scented glands in secretion and non-secretion season.

The scented gland is an organ responsible for producing musk in muskrats. During musk secretion season, the metabolism of glandular cells increases in the scented glands and a large amount of musk is synthesised. In this study, we collected scented gland arterial blood from six healthy adult male muskrats during non-secretion season (November). We also obtained scented gland arterial blood, venous blood, and musk from six healthy adult males during secretion season (March). Qualitative and quantitative analyses of free amino acids in blood and musk were performed with an automated amino acid analyzer. Additionally, we employed RNA sequencing technology to study the expression patterns of amino acid metabolic pathways in scented glands. Amino acid profile analysis indicates that scented glands can concentrate amino acids during secretion season, and transcriptome analysis suggests that some amino acid metabolism-related genes undergo significant seasonal changes. In summary, scented gland amino acid metabolism displays seasonal differences. Elevated amino acid metabolic activity during secretion season sustains the glands' secretory function.