Properties, Genetics and Innate Immune Function of the Cuticle in Egg-Laying Species.
Properties, Genetics and Innate Immune Function of the Cuticle in Egg-Laying Species.
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DOI：
10.3389/fimmu.2022.838525
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发表时间：
2022
影响因子：
7.3
通讯作者：
Hincke MT
中科院分区：
文献类型：
--
作者：
Kulshreshtha G;D'Alba L;Dunn IC;Rehault-Godbert S;Rodriguez-Navarro AB;Hincke MT
克莱德虫卵拥有非常有效和有组织的系统来保护胚胎免受外部微生物的伤害，直到孵化。在许多鸟类和一些爬行动物中，角质层是壳层表面的蛋白层。一个完整的角质层形成一个毛孔堵塞，堵塞呼吸毛孔，是一个有效的物理和化学屏障，防止微生物渗透。鸡蛋的内部通常被认为是无菌的，而蛋壳外部的角质层是微生物的宿主。蛋壳微生物群落的多样性来自母体微生物区系和筑巢环境。鸡蛋的表面特征、外层湿润层和组成角质层的抗菌分子的存在决定了蛋壳表面微生物群落的组成。在不同的地面筑巢物种中，鸟类的角质层影响蛋壳的润湿性、水蒸气导度和紫外线反射率；此外，它的组成、厚度和覆盖程度取决于物种、母鸡年龄和生理应激因素。对国内禽类的研究表明，就沙门氏菌和大肠杆菌等细菌病原体污染的风险而言，角质层的变化会影响鸡蛋的食品安全。此外，防止内部蛋成分的污染是优化鸟类孵化成功的关键。在鸡中，有中等遗传力(38%)的角质层沉积具有遗传改良的潜力。然而，对其他鸟类或爬行动物角质层的了解要少得多。本文综述了有关蛋壳角质层的研究现状，并对其在爬行动物分支中的进化提供了深入的认识。详细讨论了蛋壳微生物群的起源、组成和调节，以及角质层作为鸡蛋防御的第一屏障的潜在功能。根据污染风险，我们评估了角质层的变化如何影响食用鸡蛋的食品安全和病原体在生产链中的垂直传播。因此，本文综述了蛋壳角质层在蛋禽和爬行动物中与其保护功能(先天免疫)有关的生理和微生物学特性。
Cleidoic eggs possess very efficient and orchestrated systems to protect the embryo from external microbes until hatch. The cuticle is a proteinaceous layer on the shell surface in many bird and some reptile species. An intact cuticle forms a pore plug to occlude respiratory pores and is an effective physical and chemical barrier against microbial penetration. The interior of the egg is assumed to be normally sterile, while the outer eggshell cuticle hosts microbes. The diversity of the eggshell microbiome is derived from both maternal microbiota and those of the nesting environment. The surface characteristics of the egg, outer moisture layer and the presence of antimicrobial molecules composing the cuticle dictate constituents of the microbial communities on the eggshell surface. The avian cuticle affects eggshell wettability, water vapor conductance and regulates ultraviolet reflectance in various ground-nesting species; moreover, its composition, thickness and degree of coverage are dependent on species, hen age, and physiological stressors. Studies in domestic avian species have demonstrated that changes in the cuticle affect the food safety of eggs with respect to the risk of contamination by bacterial pathogens such as Salmonella and Escherichia coli. Moreover, preventing contamination of internal egg components is crucial to optimize hatching success in bird species. In chickens there is moderate heritability (38%) of cuticle deposition with a potential for genetic improvement. However, much less is known about other bird or reptile cuticles. This review synthesizes current knowledge of eggshell cuticle and provides insight into its evolution in the clade reptilia. The origin, composition and regulation of the eggshell microbiome and the potential function of the cuticle as the first barrier of egg defense are discussed in detail. We evaluate how changes in the cuticle affect the food safety of table eggs and vertical transmission of pathogens in the production chain with respect to the risk of contamination. Thus, this review provides insight into the physiological and microbiological characteristics of eggshell cuticle in relation to its protective function (innate immunity) in egg-laying birds and reptiles.