母鸡老化导致的蛋壳质量下降对鸡蛋行业的经济利益构成威胁。随着年龄的增长,蛋壳质量的下降可以归因于其超微结构和化学成分的变化。蛋壳中的特定基质蛋白在控制晶体生长和调节结构组织中起作用。然而,对老化母鸡蛋壳的超微结构和有机基质的变化知之甚少。这项研究评估了身体特征,机械质量,化学成分,以及38、58、78和108周龄的JingTint6母鸡卵的微观结构和纳米结构特性。随后,进行了定量蛋白质组学分析,以确定38至108周龄蛋壳中蛋白质丰度的差异。结果表明,壳厚度显著下降,断裂强度,索引,断裂韧性,与其他组相比,108周龄组的硬度和硬度(P<0.05)。超微结构变化主要涉及108周龄组的乳头层比例增加和蛋壳有效层厚度减小(P<0.05)。然而,各年龄组蛋壳组成无显著差异(P>0.05)。蛋白质组学分析显示,在38周年龄组和108周年龄组的蛋壳中鉴定出76种差异表达蛋白(DEP),其中包含与生物矿化相关的蛋白质,钙离子结合,豁免权,以及蛋白质合成和折叠。Ovocleidin-116,骨桥蛋白的下调,和钙离子相关的蛋白质,随着卵清蛋白的上调,溶菌酶C,和抗菌蛋白,有可能影响蛋壳的结构组织。因此,随着年龄的增长,蛋壳质量的下降可能归因于超微结构的改变和基质蛋白的丰富。
The decline in eggshell quality resulting from aging hens poses a threat to the financial benefits of the egg industry. The deterioration of eggshell quality with age can be attributed to changes in its ultrastructure and chemical composition. Specific matrix proteins in eggshells have a role in controlling crystal growth and regulating structural organization. However, the variations in ultrastructure and organic matrix of eggshells in aging hens remain poorly understood. This study assessed the physical traits, mechanical quality, chemical content, as well as the microstructural and nanostructural properties of eggs from Jing Tint 6 hens at 38, 58, 78, and 108 wk of age. Subsequently, a quantitative proteomic analysis was conducted to identify differences in protein abundance in eggshells between the ages of 38 and 108 wk. The results indicated a notable decline in shell thickness, breaking strength, index, fracture toughness, and stiffness in the 108-wk-age group compared to the other groups (P < 0.05). The ultrastructure variations primarily involved an increased ratio of the mammillary layer and a reduced thickness of the effective layer of eggshell in the 108-wk-age group (P < 0.05). However, no significant differences in eggshell compositions were observed among the various age groups (P > 0.05). Proteomic analysis revealed the identification of 76 differentially expressed proteins (DEPs) in the eggshells of the 38-wk-age group and 108-wk-age group, which comprised proteins associated with biomineralization, calcium ion binding, immunity, as well as protein synthesis and folding. The downregulation of ovocleidin-116, osteopontin, and calcium-ion-related proteins, together with the upregulation of ovalbumin, lysozyme C, and antimicrobial proteins, has the potential to influence the structural organization of the eggshell. Therefore, the deterioration of eggshell quality with age may be attributed to the alterations in ultrastructure and the abundance of matrix proteins.