Some observations on the structure and function of the spinning apparatus in the silkworm Bombyx mori
Some observations on the structure and function of the spinning apparatus in the silkworm Bombyx mori
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DOI：
10.1021/bm060874z
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发表时间：
2007-01-01
影响因子：
6.2
通讯作者：
Knight, David
中科院分区：
文献类型：
--
作者：
Asakura, Tetsuo;Umemura, Kosuke;Knight, David
蚕丝具有优异的机械性能，尽管是在室温和水溶液中纺制的。虽然已经提出纤维的形成主要是由纤维中的剪切和拉伸流动引起的，但是家蚕纺丝器的详细结构和功能仍然没有完全阐明。在本文中，我们描述了三个方面的功能显微解剖的纺纱装置：丝腺导管的直径的变化与距离沿着管道，如何双折射的丝蛋白的变化，因为它向下流动的管道，和详细的三维结构的压力机和相关的结构。双逃逸液晶织构的存在下，在一个区域的管道中的丝素蛋白进行了描述。在该区域之后，双折射突然消失，直到内部拉伸锥形开始，该内部拉伸锥形刚好在丝网压榨之前开始。在内部下拉锥中，当从丝心蛋白凝胶中拉出线时，双折射率急剧增加至渐近值。压丝机的结构表明，它作为一个限制模具，其直径可以调节。
Silkworm silk has outstanding mechanical properties despite being spun at room temperature and from aqueous solution. Although it has been proposed that fiber formation is mainly induced by shearing and extensional flow in the spinneret, the detailed structure and function of the spinning apparatus of Bombyx mori silkworms are still not fully elucidated. In this paper we describe three aspects of the functional microanatomy of the spinning apparatus: changes in the diameter of the silk gland duct with distance along the duct, how the birefringence of the fibroin changes as it flows down the duct, and the detailed three-dimensional structure of the silk press and related structures. The existence of a double escaped nematic liquid crystal texture in the fibroin in a region of the duct is described. After this region the birefringence suddenly disappeared until the start of an internal draw down taper which commenced just before the silk press. In the internal draw down taper the birefringence increased dramatically to an asymptotic value as a thread was drawn from the fibroin gel. The structure of the silk press suggests that it acts as a restriction die whose diameter can be regulated.