McLean Lynn, Doherty Mary K, Deeming D Charles, Beynon Robert J
Department of Veterinary Preclinical Sciences, University of Liverpool, Liverpool L69 7ZJ, United Kingdom.
Mol Cell Proteomics. 2004 Mar;3(3):250-6. doi: 10.1074/mcp.M300104-MCP200. Epub 2004 Jan 13.
An appropriate level of water loss from eggs is critical to successful hatching. This water may be lost from the egg by evaporation, but where water loss is suboptimal, it is commonly observed that the hatchlings contain substantial amounts of a subcutaneous gel-like fluid. To characterize this fluid, we have analyzed the proteins that are contained within it. The protein complement comprised a small number of proteins in high concentrations. Proteomics analysis of the constituent proteins identified virtually all of these abundant proteins and confirmed that the subcutaneous gel was very similar in protein composition to plasma. However, the subcutaneous gel was substantially depleted of fibrinogen. It is possible that activation of the final stages of the coagulation process might account for the enhanced viscosity, creating a gel-like material that is relatively immobile in the subcutaneous space. This gel may function as a water volume that is partitioned during embryonic development in order to mitigate the effects of high water content of the egg caused by low mass loss during incubation and in some instances might also function as a water reserve to support the hatchling in the first few hours of life free of the shell.
卵的适度失水对成功孵化至关重要。这种水分可能通过蒸发从卵中流失，但在失水不理想的情况下，通常会观察到幼体含有大量皮下凝胶状液体。为了表征这种液体，我们分析了其中所含的蛋白质。蛋白质组成包括少量高浓度的蛋白质。对组成蛋白质的蛋白质组学分析几乎鉴定出了所有这些丰富的蛋白质，并证实皮下凝胶在蛋白质组成上与血浆非常相似。然而，皮下凝胶中的纤维蛋白原大量减少。凝血过程最后阶段的激活可能导致粘度增加，形成一种在皮下空间相对不流动的凝胶状物质。这种凝胶可能起到在胚胎发育过程中分配水量的作用，以减轻孵化期间质量损失低导致的卵含水量过高的影响，在某些情况下还可能作为水储备，在幼体脱离蛋壳后的最初几个小时内为其提供支持。
