Tang Zhixiong, Li Jianfu, Zhou Bin, Zhang Bohao, Zhang Junjun, Cheng Shuru, Dong Weitao, Zhang Yong, Zhao Xingxu, Zhang Quanwei, Gao Yuan
College of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China; Gansu Key Laboratory of Animal Generational Physiology and Reproductive Regulation, Lanzhou 730070, China.
Gansu Key Laboratory of Animal Generational Physiology and Reproductive Regulation, Lanzhou 730070, China; College of Life Science and Technology, Gansu Agricultural University, Lanzhou 730070, China.
Int J Biol Macromol. 2025 Jul;318(Pt 2):145042. doi: 10.1016/j.ijbiomac.2025.145042. Epub 2025 Jun 6.
In the breeding season, male Bactrian camels (Camelus Bactrianus) secrete a large amount of pale-yellow watery secretions with a characteristic odor from the poll glands and spread urine by wagging their tails, which can induce estrus and mating in female camels. However, the compositions of the urine and poll glands secretions during the breeding season are poorly understood. Thus, we investigated the unique secretions of poll glands and identified key metabolites during the breeding season. Neck mane and urine from male camels before and during the breeding season were collected for liquid chromatography-mass spectrometry (LC-MS) analysis to identify differentially expressed metabolites (DEMs). Moreover, poll gland tissue from male camels during breeding periods was collected for LC-MS and data-independent acquisition proteomic analysis to identify the DEMs, differentially expressed proteins, and signaling pathways. Creatine was mainly enriched in the arginine and proline metabolic pathways, highly expressed, and a common metabolite in the poll glands, neck mane, and urine of male Bactrian camels during breeding periods. Immunohistochemical and immunofluorescence assays showed that glycine amidine transferase (GATM) and aldehyde dehydrogenase 18 family member A1 (ALDH18A1), which are closely related to creatine synthesis, were expressed and co-localized in the cytoplasm of poll gland epithelial cells. Quantitative real-time PCR and western blot assays revealed that creatine content and GATM and ALDH18A1 expression levels were significantly increased in the poll glands of active mating camels. These results demonstrate that creatine is a key metabolite in the poll gland secretions and urine of male Bactrian camels during the breeding season and that changes in creatine content are associated with the breeding behavior of male Bactrian camels. This study provides insights into the role of creatine in male Bactrian camels during the breeding season.
在繁殖季节，雄性双峰驼（Camelus Bactrianus）的包皮腺会分泌大量淡黄色的水样分泌物，带有独特气味，并且会通过摇尾巴来散播尿液，这能够诱导雌性骆驼发情和交配。然而，对于繁殖季节尿液和包皮腺分泌物的成分却知之甚少。因此，我们研究了包皮腺的独特分泌物，并鉴定了繁殖季节期间的关键代谢物。收集繁殖季节前后雄性骆驼的颈部鬃毛和尿液用于液相色谱 - 质谱（LC - MS）分析以鉴定差异表达代谢物（DEM）。此外，收集繁殖期雄性骆驼的包皮腺组织用于LC - MS和数据非依赖采集蛋白质组分析，以鉴定DEM、差异表达蛋白质和信号通路。肌酸主要富集于精氨酸和脯氨酸代谢途径，表达量高，是繁殖期雄性双峰驼包皮腺、颈部鬃毛和尿液中的一种常见代谢物。免疫组织化学和免疫荧光分析表明，与肌酸合成密切相关的甘氨酸脒基转移酶（GATM）和醛脱氢酶18家族成员A1（ALDH18A1）在包皮腺上皮细胞的细胞质中表达并共定位。定量实时PCR和蛋白质免疫印迹分析显示，处于活跃交配状态的骆驼包皮腺中肌酸含量以及GATM和ALDH18A1的表达水平显著增加。这些结果表明，肌酸是繁殖季节雄性双峰驼包皮腺分泌物和尿液中的关键代谢物，并且肌酸含量的变化与雄性双峰驼的繁殖行为相关。本研究为肌酸在雄性双峰驼繁殖季节中的作用提供了见解。
