Department of Animal Resource Production, Gifu University, Gifu 501-1193, Japan.
Poult Sci. 2009 Dec;88(12):2670-6. doi: 10.3382/ps.2009-00108.
Two calcified structures, the eggshell and sperm-associated body (SB), are present in the eggs of the Japanese quail, Coturnix japonica. X-ray diffractometry showed that calcium carbonates take the form of calcite in the eggshell and aragonite in the SB. The aim of the present study was to identify the factors that determine the morphology of calcium carbonate crystals. The matrix of EDTA-treated eggshell was a meshwork of vesicles, 200 to 500 nm in diameter, connected by fine fibers or fibrous sheets. The matrix of SB cortex was a radiation of rod-shaped projections approximately 130 nm in width. In vitro crystal formation was achieved by adding dissociated matrix substances to test solutions. When eggshell matrix material was added, formation of calcite crystals, which had many vesicular holes on their surface, was observed. When SB matrix material dissociated by sonication was added, rhombohedral calcite crystals formed at protein concentrations of 100 microg/mL or lower, and elongated and bundled crystals formed at concentrations of 150 microg/mL or higher. When SB matrix material dissociated by pipetting was added, aragonite crystals formed. These observations indicate that the matrix structure is the principal factor in determining the crystal polymorphism of calcium carbonate.
两种钙化结构，蛋壳和精子相关体（SB），存在于日本鹌鹑 Coturnix japonica 的卵中。X 射线衍射分析表明，蛋壳中的碳酸钙形式为方解石，SB 中的碳酸钙形式为文石。本研究的目的是确定决定碳酸钙晶体形态的因素。EDTA 处理的蛋壳基质是直径为 200 至 500nm 的泡囊的网格，通过细纤维或纤维片连接。SB 皮质基质是约 130nm 宽的棒状突起的辐射。体外晶体形成是通过将分离的基质物质添加到测试溶液中实现的。当添加蛋壳基质材料时，观察到表面有许多泡囊孔的方解石晶体形成。当添加通过超声处理解离的 SB 基质材料时，在蛋白质浓度为 100μg/mL 或更低时形成菱面体方解石晶体，在浓度为 150μg/mL 或更高时形成拉长和束状晶体。当添加通过移液管解离的 SB 基质材料时，形成文石晶体。这些观察结果表明，基质结构是决定碳酸钙晶体多型性的主要因素。
