Ultrastructure of avian eggshell during resorption following egg fertilization
Ultrastructure of avian eggshell during resorption following egg fertilization
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DOI：
10.1016/j.jsb.2009.07.005
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发表时间：
2009-12-01
影响因子：
3
通讯作者：
McKee, M. D.
中科院分区：
文献类型：
--
作者：
Chien, Y. -C.;Hincke, M. T.;McKee, M. D.
为了骨骼矿化，鸟类胚胎从其钙化蛋壳中动员钙。这是通过壳的特定内部区域的溶解发生的，这个过程也削弱了壳，使其能够孵化。在这里，我们研究了在受精卵（孵化）和小鸡（Gallus Gallus）孵化之间发生的溶解过程中蛋壳的超微结构。我们关注的是大多数溶解发生的壳类哺乳动物的变化。利用扫描电子显微镜，我们描述了在未受精卵（未被吸收的蛋壳）中未观察到的基质-矿物结构和关系的差异。我们记录了钙储备体的变化-哺乳动物的一个重要的亚室-与它是胚胎骨骼生长所必需的钙的早期主要来源相一致。钙储备囊和钙储备体底板的溶解事件，以及周围大乳头结构的类似变化，都与骨骼胚胎钙化的推进有关。哺乳动物亚结构的变化通常可以表征为矿物溶解在剩余矿物表面上显示出精细的表面地形，以及广泛的晶体内（封闭）有机基质网络的暴露。我们提出，这种矿物质闭塞网络通过提供溶解通道促进胚胎骨骼钙的释放来调节壳矿物的溶解方式。爱思唯尔公司2009年版权所有版权所有。
For skeletal mineralization, the avian embryo mobilizes calcium from its calcitic eggshell. This occurs through dissolution of specific interior regions of the shell in a process that also weakens the shell to allow hatching. Here, we have examined eggshell ultrastructure during dissolution occurring between laying of a fertilized egg (with incubation) and hatching of the chick (Gallus gallus). We have focused on changes in shell mammillae where the majority of dissolution takes place. Using scanning electron microscopy, we describe differences in matrix-mineral structure and relationships not observed in unfertilized eggs (unresorbed eggshell). We document changes in the calcium reserve body - an essential sub-compartment of mammillae - consistent with it being an early, primary source of calcium essential for embryonic skeletal growth. Dissolution events occurring in the calcium reserve sac and in the base plate of the calcium reserve body, and similar changes in surrounding bulk mammillae structure, all correlate with advancing skeletal embryonic calcification. The changes in mammillae sub-structures can generally be characterized as mineral dissolutions revealing fine surface topographies on remaining mineral surfaces and the exposure of an extensive, intracrystalline (occluded) organic matrix network. We propose that this mineral-occluded network regulates how shell mineral is dissolved by providing dissolution channels facilitating calcium release for the embryonic skeleton. Crown Copyright (C) 2009 Published by Elsevier Inc. All rights reserved.