BOA, INRA, Université de Tours, 37380 Nouzilly, France.
PRC, INRA, CNRS, IFCE, Université de Tours, Nouzilly 37380, France.
Mol Cell Proteomics. 2019 Mar 15;18(Suppl 1):S174-S190. doi: 10.1074/mcp.RA117.000459. Epub 2018 Feb 14.
In many amniotes, the amniotic fluid is depicted as a dynamic milieu that participates in the protection of the embryo (cushioning, hydration, and immunity). However, in birds, the protein profile of the amniotic fluid remains unexplored, even though its proteomic signature is predicted to differ compared with that of humans. In fact, unlike humans, chicken amniotic fluid does not collect excretory products and its protein composition strikingly changes at mid-development because of the massive inflow of egg white proteins, which are thereafter swallowed by the embryo to support its growth. Using GeLC-MS/MS and shotgun strategies, we identified 91 nonredundant proteins delineating the chicken amniotic fluid proteome at day 11 of development, before egg white transfer. These proteins were essentially associated with the metabolism of nutrients, immune response and developmental processes. Forty-eight proteins were common to both chicken and human amniotic fluids, including serum albumin, apolipoprotein A1 and alpha-fetoprotein. We further investigated the effective role of chicken amniotic fluid in innate defense and revealed that it exhibits significant antibacterial activity at day 11 of development. This antibacterial potential is drastically enhanced after egg white transfer, presumably due to lysozyme, avian beta-defensin 11, vitelline membrane outer layer protein 1, and beta-microseminoprotein-like as the most likely antibacterial candidates. Interestingly, several proteins recovered in the chicken amniotic fluid prior and after egg white transfer are uniquely found in birds (ovalbumin and related proteins X and Y, avian beta-defensin 11) or oviparous species (vitellogenins 1 and 2, riboflavin-binding protein). This study provides an integrative overview of the chicken amniotic fluid proteome and opens stimulating perspectives in deciphering the role of avian egg-specific proteins in embryonic development, including innate immunity. These proteins may constitute valuable biomarkers for poultry production to detect hazardous situations (stress, infection, etc.), that may negatively affect the development of the chicken embryo.
在许多羊膜动物中，羊水被描绘为一种参与保护胚胎的动态环境（缓冲、水合和免疫）。然而，在鸟类中，羊水的蛋白质谱仍未被探索，尽管其蛋白质组学特征预计与人类不同。事实上，与人类不同的是，鸡羊水不会收集排泄物，其蛋白质组成在中期发育时会发生显著变化，因为大量的蛋清蛋白涌入，然后被胚胎吞噬，以支持其生长。使用 GeLC-MS/MS 和鸟枪法策略，我们在蛋清转移前的发育第 11 天鉴定了 91 个非冗余蛋白，这些蛋白描绘了鸡羊水的蛋白质组。这些蛋白主要与营养物质代谢、免疫反应和发育过程有关。48 种蛋白在鸡和人羊水中共存，包括血清白蛋白、载脂蛋白 A1 和甲胎蛋白。我们进一步研究了鸡羊水在先天防御中的有效作用，发现它在发育第 11 天就具有显著的抗菌活性。这种抗菌潜力在蛋清转移后大大增强，推测是由于溶菌酶、禽β-防御素 11、卵黄膜外层蛋白 1 和β-微精蛋白样蛋白是最有可能的抗菌候选物。有趣的是，在蛋清转移前后从鸡羊水回收的几种蛋白仅在鸟类（卵白蛋白和相关蛋白 X 和 Y、禽β-防御素 11）或卵生动物（卵黄原蛋白 1 和 2、核黄素结合蛋白）中发现。本研究提供了鸡羊水蛋白质组的综合概述，并为阐明鸟类卵特异性蛋白在胚胎发育中的作用，包括先天免疫，提供了新的思路。这些蛋白可能成为家禽生产中检测危险情况（应激、感染等）的有价值的生物标志物，这些情况可能会对鸡胚胎的发育产生负面影响。
