Although the microcrustacean Daphnia is becoming an organism of choice for proteomic studies, protein expression across its life cycle have not been fully characterized. Proteomes of adult females, juveniles, asexually produced embryos, and the ephippia-resting stages containing sexually produced diapausing freezing- and desiccation-resistant embryos are analyzed. Overall, proteins with known molecular functions are more likely to be detected than proteins with no detectable orthology. Similarly, proteins with stronger gene model support in two independent genome assemblies can be detected, than those without such support. This suggests that the proteomics pipeline can be applied to verify hypothesized proteins, even given questionable reference gene models. In particular, upregulation of vitellogenins and downregulation of actins and myosins in embryos of both types, relative to juveniles and adults, and overrepresentation of cell-cycle related proteins in the developing embryos, relative to diapausing embryos and adults, are observed. Upregulation of small heat-shock proteins and peroxidases, as well as overrepresentation of stress-response proteins in the ephippium relative to the asexually produced non-diapausing embryos, is found. The ephippium also shows upregulation of three trehalose-synthesis proteins and downregulation of a trehalose hydrolase, consistent with the role of trehalose in protection against freezing and desiccation.

中文翻译：

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定量蛋白质组学揭示了水蚤整个生命阶段蛋白质库的重塑。

尽管微甲壳类水蚤正在成为蛋白质组学研究的首选生物，但尚未对其整个生命周期中的蛋白质表达进行充分表征。分析了成年雌性，幼体，无性繁殖的胚胎的蛋白质组，以及包含有性繁殖的滞育性的抗冷冻和抗干燥胚胎的ephephia-resting阶段。总体而言，具有已知分子功能的蛋白质比没有可检测的正畸学的蛋白质更有可能被检测到。同样，与没有这种支持的蛋白质相比，可以检测到在两个独立的基因组装配中具有更强的基因模型支持的蛋白质。这表明，即使给出了可疑的参考基因模型，蛋白质组学流水线也可以用于验证假设的蛋白质。特别是，相对于少年和成年，这两种类型的胚胎中卵黄蛋白原的上调以及肌动蛋白和肌球蛋白的下调，相对于滞育性的胚胎和成年，观察到发育中的胚胎中细胞周期相关蛋白的过度表达。发现相对于无性繁殖的无尿胚胎，小热休克蛋白和过氧化物酶的上调，以及ipp中应激反应蛋白的过度表达。也显示三种海藻糖合成蛋白的上调和海藻糖水解酶的下调，这与海藻糖在防止冷冻和干燥中的作用一致。被观察到。发现相对于无性繁殖的无尿胚胎，小热休克蛋白和过氧化物酶的上调，以及ipp中应激反应蛋白的过度表达。也显示三种海藻糖合成蛋白的上调和海藻糖水解酶的下调，这与海藻糖在防止冷冻和干燥中的作用一致。被观察到。发现相对于无性繁殖的无尿胚胎，小热休克蛋白和过氧化物酶的上调，以及ipp中应激反应蛋白的过度表达。也显示三种海藻糖合成蛋白的上调和海藻糖水解酶的下调，这与海藻糖在防止冷冻和干燥中的作用一致。