College of Animal Sciences, Jilin University, Changchun, China.
Chengdu Research Base of Giant Panda Breeding, Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Sichuan Academy of Giant Panda, Chengdu, China.
Front Endocrinol (Lausanne). 2020 Apr 16;11:215. doi: 10.3389/fendo.2020.00215. eCollection 2020.
Giant pandas represent one of the most endangered species worldwide, and their reproductive capacity is extremely low. They have a relatively long gestational period, mainly because embryo implantation is delayed. Giant panda cubs comprise only a small proportion of the mother's body weight, making it difficult to determine whether a giant panda is pregnant. Timely determination of pregnancy contributes to the efficient breeding and management of giant pandas. Meanwhile, metabolomics studies the metabolic composition of biological samples, which can reflect metabolic functions in cells, tissues, and organisms. This work explored the urinary metabolites of giant pandas during pregnancy. A sample of 8 female pandas was selected. Differences in metabolite levels in giant panda urine samples were analyzed via ultra-high-performance liquid chromatography/mass spectrometry comparing pregnancy to anoestrus. Pattern recognition techniques, including partial least squares-discriminant analysis and orthogonal partial least squares-discriminant analysis, were used to analyze multiple parameters of the data. Compared with the results during anoestrus, multivariate statistical analysis of results obtained from the same pandas being pregnant identified 16 differential metabolites in the positive-ion mode and 43 differential metabolites in the negative-ion mode. The levels of tryptophan, choline, kynurenic acid, uric acid, indole-3-acetaldehyde, taurine, and betaine were higher in samples during pregnancy, whereas those of xanthurenic acid and S-adenosylhomocysteine were lower. Amino acid metabolism, lipid metabolism, and organic acid production differed significantly between anoestrus and pregnancy. Our results provide new insights into metabolic changes in the urine of giant pandas during pregnancy, and the differential levels of metabolites in urine provide a basis for determining pregnancy in giant pandas. Understanding these metabolic changes could be helpful for managing pregnant pandas to provide proper nutrients to their fetuses.
大熊猫是全球最濒危物种之一，其繁殖能力极低。它们的妊娠期相对较长，主要是因为胚胎着床延迟。大熊猫幼仔仅占母体体重的一小部分，因此很难确定大熊猫是否怀孕。及时确定怀孕有助于大熊猫的高效繁殖和管理。同时，代谢组学研究生物样本的代谢成分，可以反映细胞、组织和生物体的代谢功能。本研究探讨了大熊猫妊娠期的尿液代谢物。选择了 8 只雌性大熊猫作为样本。通过比较发情期和非发情期的超高效液相色谱/质谱分析，分析了大熊猫尿液样本中代谢物水平的差异。采用偏最小二乘判别分析和正交偏最小二乘判别分析等模式识别技术，对多个参数进行了数据分析。与非发情期结果相比，对同一怀孕大熊猫的结果进行多元统计分析，在正离子模式下鉴定出 16 种差异代谢物，在负离子模式下鉴定出 43 种差异代谢物。在怀孕样本中，色氨酸、胆碱、犬尿氨酸、尿酸、吲哚-3-乙醛、牛磺酸和甜菜碱的水平较高，而黄尿酸和 S-腺苷同型半胱氨酸的水平较低。氨基酸代谢、脂类代谢和有机酸生成在发情期和怀孕期之间有显著差异。我们的研究结果为大熊猫妊娠期尿液代谢变化提供了新的见解，尿液中代谢物的差异水平为确定大熊猫怀孕提供了依据。了解这些代谢变化有助于管理怀孕的大熊猫，为其胎儿提供适当的营养。
