Urates of colubroid snakes are different from those of boids and pythonids
Urates of colubroid snakes are different from those of boids and pythonids
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DOI：
10.1093/biolinnean/blab052
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发表时间：
2021-04
影响因子：
1.9
通讯作者：
Alyssa M. Thornton;G. W. Schuett;J. Swift
中科院分区：
文献类型：
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作者：
Alyssa M. Thornton;G. W. Schuett;J. Swift
排尿酸的物种，例如有鳞爬行动物、鸟类和昆虫，能够以固体形式的尿酸（通常称为尿酸盐）有效地消除氮。十多年来的观察表明，蛇类（现代蛇类）产生的空尿酸盐与蛇类和蟒蛇（古代蛇类）产生的尿酸盐存在显着差异。在这里，我们比较了喂食相同饮食的八种圈养蛇产生的尿酸盐。尽管所有新鲜尿酸盐在排泄时都是湿的，但现代蛇产生的尿酸盐干燥成粉末状固体，而古代蛇类产生的尿酸盐干燥成坚硬的物质，紧紧粘附在表面上。对五种现代蛇和三种古代蛇产生的空隙尿酸盐进行粉末 X 射线衍射和红外光谱分析，证实了它们潜在的化学和结构差异。古代蛇排出的尿酸盐是无定形尿酸，而现代蛇排出的尿酸盐主要由尿酸铵组成，还含有一些二水尿酸。这些成分差异表明蛇有不止一种管理含氮废物的机制。为什么不同的物种使用不同的氮处理途径尚不清楚，但答案可能与新陈代谢、生理学的关键差异有关，或者对于古代蛇来说，与社会交流中尿酸盐的潜在用途有关。
Uricotelic species, such as squamate reptiles, birds and insects, effectively eliminate nitrogen as uric acid in a solid form commonly called urates. Observations made over a decade suggested that the voided urates produced by colubroids (modern snake species) exhibit remarkable differences from those of boids and pythons (ancient snake species). Here, we compare the urates generated by eight captive snake species fed the same diet. Although all fresh urates were wet at the time of excretion, those produced by modern snakes dried to a powdery solid, whereas those of ancient species dried to a rock-hard mass that was tightly adherent to surfaces. Powder X-ray diffraction and infrared spectroscopy analyses performed on voided urates produced by five modern and three ancient snakes confirmed their underlying chemical and structural differences. Urates excreted by ancient snakes were amorphous uric acid, whereas urates from modern snakes consisted primarily of ammonium acid urate, with some uric acid dihydrate. These compositional differences indicate that snakes have more than one mechanism to manage nitrogenous waste. Why different species use different nitrogen-handling pathways is not yet known, but the answer might be related to key differences in metabolism, physiology or, in the case of ancient snakes, the potential use of urates in social communication.