家蚕五龄幼虫中部丝腺细胞的蛋白质组成比较

 对家蚕5龄期中部丝腺细胞不同区段的蛋白质组成研究，有利于发现与丝胶蛋白合成和分泌有关的功能蛋白质。本研究采用蛋白质双向电泳和图像分析技术，发现家蚕中部丝腺前、中、后3个不同区段的细胞的蛋白质组成具有显著差异；仅在前段表达的20个特异性蛋白质，可能与Ser2A、Ser2B、S4和S5这4种丝胶蛋白的合成与分泌有关；仅在中段表达的22个特异性蛋白质，可能与Ser1B、Ser1C、Ser1D和S3这4种丝胶蛋白的合成与分泌有关；仅在后段表达的27个特异性蛋白质，可能与Ser1A和S3这2种丝胶蛋白的合成与分泌有关。另外，在中段和后段表达、前段不表达的51个差异性蛋白质、表达量在中段和后段比在前段高的20个差异性蛋白质，可能参与了中、后段相应的丝胶蛋白的合成。

A Comparison of the Protein Composition of the Middle Silk Gland Cells of the Fifth Instar Larvae of Silkworm

Research of the protein composition of different parts of the middle silk gland (MSG) cells of the fifth instar larvae of silkworm (Bombyx mori L.)are useful to find the functional protein concerned with the composition and secretion of the sericin protein. Using the protein two dimensional electrophoresis (2D-PAGE) and the image analysis technology, a significant differences of the protein composition among the anterior, middle and posterior parts of the MSG cells of silkworm were found. Twenty specific proteins that expressed only in anterior part of the MSG cells were likely to relate with the composition and secretion of 4 kinds of sericin proteins, which are Ser2A, Ser2B, S4 and S5. Twenty-two specific proteins that expressed only in middle part of the MSG cells were likely to relate with the composition and secretion of 4 kinds of sericin proteins, which are Ser1B, Ser1C, Ser1D and S3. Twenty-seven specific proteins that expressed only in posterior part of the MSG cells were likely to relate with the composition and secretion of 2 kinds of sericin proteins, which are Ser1A and S3. Moreover, fifty-one specific proteins which expressed in middle and posterior, but not in anterior part of MSG cells and twenty proteins whose volume in middle and posterior part of MSG cells were higher than that in anterior part likely participated in the synthesis of the sericin protein of the corresponding parts.