Sperm proteome and sperm parameters of captive Amazon squirrel monkeys (Saimiri collinsi Osgood, 1916) during nonfatted and fatted condition

The present study evaluates the sperm proteome after the dilution of the seminal coagulum and the sperm parameters during nonfatted and fatted conditions in Saimiri collinsi (Amazon squirrel monkey). Thirty-five semen samples were collected by electroejaculation, and extracted proteins were trypsin-digested, desalted, and analyzed by LC-MS/MS. The Mascot software searches were performed on an in-house server against an online Saimiri boliviensis boliviensis database. Label-free LC-MS/MS allowed the identification of 1,161 proteins in sperm samples. Out of the 65 proteins that were differently expressed. The most important biological processes related to the upregulation of in animals of nonfatted condition were cellular processes and metabolic processes. The main molecular functions of these proteins were determined to be catalytic activity and binding. Sperm proteins were mainly defined as cellular anatomical entities and protein complexes, as cellular components. The protein classes identified in the study included metabolite interconversion enzyme, transport, chaperone, and protein modifying enzyme. In fatted condition, the most important biological processes related to the upregulation proteins were cellular processes, metabolic processes, and localization. The main molecular functions of these proteins were determined to be binding, catalytic activity, ATP-dependent activity, and transport activity. Regarding cellular components, the proteins were mainly defined as cellular anatomical entities and protein complexes. The study identified protein classes included cytoskeletal protein, metabolite interconversion enzyme, transporter, RNA metabolism protein, chaperone and Protein modifying enzyme. After analyzing the data using DAVID, we discovered that 20 genes were in nonfatted and 25 genes in fatted conditions. In nonfatted conditions associated with biological processes, molecular functions such as chaperone and cellular components such as cilium, flagellum, and cell projection. In fatted conditions, proteins were highly represented in biological processes such as fertilization, spermatogenesis, and transport, also involved in molecular functions such as chaperone and motor protein, and cellular components such as dynein, cytoskeleton, proteasome, cell projection, and cytoplasm. This represents the most comprehensive overview of the sperm proteome in the Amazon squirrel monkey sperm and will contribute to the elucidation of the underlying mechanisms associated with sperm function.

本研究针对科氏松鼠猴（Saimiri collinsi，亚马逊松鼠猴），在非脂肪化与脂肪化处理条件下，对精液凝块（seminal coagulum）稀释后的精子蛋白质组以及精子参数展开评估。
研究通过电刺激采精（electroejaculation）法收集35份精液样本，对提取的蛋白质进行胰蛋白酶消化（trypsin-digested）、脱盐处理后，采用液相色谱-串联质谱（LC-MS/MS）进行分析。依托内部服务器（in-house server）的Mascot软件（Mascot software），针对公开的玻利维亚松鼠猴（Saimiri boliviensis boliviensis）数据库进行序列检索。
无标记液相色谱-串联质谱（Label-free LC-MS/MS）分析共在精子样本中鉴定出1161种蛋白质，其中65种蛋白质呈现差异表达。
非脂肪化组上调蛋白质所关联的核心生物过程为细胞过程与代谢过程，此类蛋白质的主要分子功能为催化活性与结合活性；在细胞组分分类中，这些蛋白质主要被归类为细胞解剖实体与蛋白质复合物。本研究鉴定出的蛋白质类别包括代谢物转换酶、转运蛋白、分子伴侣以及蛋白质修饰酶。
脂肪化组上调蛋白质所关联的核心生物过程为细胞过程、代谢过程与定位过程，此类蛋白质的主要分子功能为结合活性、催化活性、ATP依赖活性以及转运活性；在细胞组分分类中，这些蛋白质同样主要归类为细胞解剖实体与蛋白质复合物。本研究鉴定出的蛋白质类别包括细胞骨架蛋白、代谢物转换酶、转运蛋白、RNA代谢蛋白、分子伴侣以及蛋白质修饰酶。
通过DAVID数据库对数据进行富集分析后发现，非脂肪化组与脂肪化组分别富集到20个与25个相关基因。非脂肪化组的相关富集条目涵盖生物过程、分子功能（如分子伴侣）以及细胞组分（如纤毛、鞭毛与细胞突起）。脂肪化组中，相关蛋白质显著富集于受精、精子发生与转运等生物过程，同时涉及分子伴侣、动力蛋白等分子功能，以及动力蛋白、细胞骨架、蛋白酶体、细胞突起与细胞质等细胞组分。
本研究是目前针对亚马逊松鼠猴精子蛋白质组最为全面的概述成果，将为阐明精子功能相关的潜在分子机制提供重要参考。