Description
Fish live in water and secret nitrogen waste as ammonia directly in water via gill; mice mainly secrete nitrogen waste as urea via the urea cycle; birds mainly secret nitrogen waste as uric acids. However, it is unclear whether their nitrogen metabolic pathways, especially urea cycle-related enzymes are regulated, thereby producing these varied nitrogen waste in these three different species. To address this question, the expression levels of urea cycle enzymes (UCEs) in different species at the mRNA, protein, and metabolic levels are compared to explore the expression and activity levels of UCEs in these three different species. Briefly, in pigeons and large yellow croakers, UCEs are expressed at very low levels in the liver, whereas GS and SLC25A13 are expressed at relatively high levels. In addition, we found very high levels of blood ammonia in fish, almost twice as high as in mice and pigeons. In conclusion, pigeons and large yellow croakers do not rely on UCEs to excrete nitrogen wastes but require GS as well as SLC25A13 for ammonia metabolism. To our knowledge, this is a quite novel project, and no published work has explored the regulatory mechanisms from the epigenetic regulation aspect yet. Understanding the regulation of UCEs under different physiological conditions may also provide helpful insights for understanding UCE dysregulation under disease conditions including cancer and gout.| Period | 1 Sept 2023 → 10 Jun 2024 |
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