Quantitative analysis of the uterine flush fluid proteome of mares in oestrus and dioestrus has been previously reported. The objectives of this study were to: a) evaluate qualitative differences in the uterine flush fluid proteome between mares in oestrus and mares in dioestrus and b) perform a functional classification of proteins either unique to each stage or common between the two stages. Uterine flush fluid samples were collected from 8 light breed mares in either oestrus (n = 5) or dioestrus (n = 3). Proteomic analysis of the samples was conducted using liquid chromatography–tandem mass spectrometry. Proteins exclusively detected in oestrus or dioestrus and those common to both stages were identified using the Scaffold software (version 4.4.8, Proteome Software Inc., Portland, OR). The identified proteins were classified into gene ontology (GO) categories (cellular component [CC], molecular function [MF] and biological process [BP]) using the PANTHER (www.pantherdb.org) classification system version 14.0. Of 172 proteins identified, 51 and 28 were exclusively detected in mares in oestrus and dioestrus, respectively, and 93 proteins were common to both stages. The most represented terms in various GO categories were similar among the three subsets of proteins. The most represented CC terms were extracellular region and cell, the most represented MF terms were catalytic activity and binding, and the most represented BP terms were metabolic process and cellular process. In conclusion, proteomic analysis of the uterine flush fluid enabled the identification of subsets of proteins unique to oestrus or dioestrus, or common to both stages. The results of this study can serve as a baseline for future research focused on finding stage‐specific protein markers or evaluating differences in the uterine flush fluid proteome between normal mares and those with uterine disease.

中文翻译：

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发情和发情期母马子宫蛋白质组的定性分析和功能分类。

先前已经报道了发情期和二发情期母马子宫冲洗液蛋白质组的定量分析。这项研究的目的是：a）评估发情母马和发情母马子宫冲洗液蛋白质组的质量差异，以及b）对每个阶段或两个阶段之间共有的蛋白质进行功能分类。从发情期（n  = 5）或二发情期（n = 3）。使用液相色谱-串联质谱法对样品进行蛋白质组学分析。使用Scaffold软件（版本4.4.8，Proteome Software Inc.，波特兰，俄勒冈州）鉴定了仅在发情期或发情期以及这两个阶段共有的蛋白质。使用PANTHER（www.pantherdb.org）分类系统14.0版将识别出的蛋白质分为基因本体（GO）类别（细胞成分[CC]，分子功能[MF]和生物过程[BP]）。在鉴定出的172种蛋白质中，分别在发情期和发情期的母马中分别检测到51种和28种，这两个阶段共有93种蛋白质。在三个GO蛋白质子集中，各种GO类别中最具代表性的术语相似。最具代表性的CC术语是细胞外区域和细胞，最典型的MF术语是催化活性和结合力，最典型的BP术语是代谢过程和细胞过程。总之，对子宫冲洗液的蛋白质组学分析能够鉴定发情期或二情期或两个阶段共有的蛋白质子集。这项研究的结果可以作为未来研究的基线，该研究的重点是寻找阶段特定的蛋白质标记或评估正常母马和患有子宫疾病的母马的子宫冲洗液蛋白质组的差异。