Pérez-Huerta Alberto, Dauphin Yannicke
Department of Geological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA.
UFR TEB, Université P. & M. Curie, case 104, 4 place Jussieu, 75252 Paris cedex 05, France.
Zoology (Jena). 2016 Feb;119(1):52-63. doi: 10.1016/j.zool.2015.11.002. Epub 2015 Nov 25.
The structure and composition of the eggshells of two commercial species (guinea fowl and greylag goose) have been studied. Thin sections and scanning electron microcopy show the similarity of the overall structure, but the relative thickness of the layers differs in these two taxa. Atomic force microscopy shows that the different layers are composed of rounded, heterogeneous granules, the diameter of which is between 50 and 100 nm, with a thin cortex. Infrared data and thermogravimetric analyses show that both eggshells are made of calcite, but differing on the quality and quantity when the organic component is considered. Chemical maps show that chemical element distribution is not uniform within a sample, and differs between the species, but with low magnesium content. Electron back scattered diffraction confirms the eggshells are calcite, but the microtexture strongly differs between the two species. Based on the chemical-structural differences, a species-specific biological control on the biomineralization is found, despite the rapid formation of an eggshell. Overall results indicate that to estimate the quality of eggshells, such as resistance to breakage, is not a straightforward process because of the high complexity of avian eggshell biomineralization.
对两种商业养殖物种（珍珠鸡和灰雁）的蛋壳结构和组成进行了研究。薄片和扫描电子显微镜显示了整体结构的相似性，但这两个分类群中层的相对厚度有所不同。原子力显微镜显示，不同的层由直径在50至100纳米之间、带有薄皮层的圆形、异质颗粒组成。红外数据和热重分析表明，两种蛋壳均由方解石制成，但在考虑有机成分时，质量和数量存在差异。化学图谱显示，样品内化学元素分布不均匀，且物种间存在差异，但镁含量较低。电子背散射衍射证实蛋壳为方解石，但两种物种的微观结构差异很大。基于化学结构差异，尽管蛋壳形成迅速，但发现了对生物矿化的物种特异性生物控制。总体结果表明，由于禽蛋壳生物矿化的高度复杂性，估计蛋壳质量（如抗破损性）并非易事。
