Trougakos I P, Margaritis L H
Division of Cell Biology and Biophysics, University of Athens, Athens, Panepistimiopolis, 15701, Greece.
J Struct Biol. 1998 Oct;123(2):111-23. doi: 10.1006/jsbi.1998.4028.
We have shown by means of conventional electron microscopy that the eggshell of Drosophila virilis at the main body of the laid egg consists of the vitelline membrane and the multilayered chorion, which includes the wax layer, the innermost chorionic layer, the endochorion, and the exochorion, while several specialized regions of the eggshell are seen across the anterior-posterior axis of the egg. Biochemical analysis revealed the existence of six quantitatively enriched chorion proteins. Among them, Dvs38 and Dvs36 are synthesized when the innermost chorionic layer and the endochorion are assembled. Immunogold electron microscopy has shown that these two proteins are incorporated in the morphologically complete vitelline membrane apparently through an intercalation process and represent structural components of the endochorion in all the specialized regions of the eggshell. Additionally, by cytochemical means, the enzyme eggshell peroxidase, which is synthesized in parallel with Dvs38 and Dvs36, has been identified as a structural component of the innermost chorionic layer and the endochorion. These findings suggest a complex protein-protein recognition pattern during the formation of the eggshell since the cosecretion of its components (i.e., Dvs38, Dvs36 chorion proteins and eggshell peroxidase) does not recommend their colocalization in the eggshell sublayers and the timing of their synthesis is not related to their final position on the eggshell (i.e., the identification of Dvs38 and Dvs36 chorion proteins as vitelline membrane components).
我们通过传统电子显微镜观察发现，果蝇卵产下时主体部分的卵壳由卵黄膜和多层绒毛膜组成，多层绒毛膜包括蜡层、最内层绒毛膜层、内 chorion 和外 chorion，而在卵的前后轴上可以看到卵壳的几个特殊区域。生化分析揭示了六种定量富集的绒毛膜蛋白的存在。其中，Dvs38 和 Dvs36 是在最内层绒毛膜层和内 chorion 组装时合成的。免疫金电子显微镜显示，这两种蛋白质显然通过插入过程整合到形态完整的卵黄膜中，并代表卵壳所有特殊区域内 chorion 的结构成分。此外，通过细胞化学方法，与 Dvs38 和 Dvs36 平行合成的酶卵壳过氧化物酶已被鉴定为最内层绒毛膜层和内 chorion 的结构成分。这些发现表明，在卵壳形成过程中存在复杂的蛋白质 - 蛋白质识别模式，因为其成分（即 Dvs38、Dvs36 绒毛膜蛋白和卵壳过氧化物酶）的共分泌并不意味着它们在卵壳亚层中共定位，并且它们的合成时间与它们在卵壳上的最终位置无关（即 Dvs38 和 Dvs36 绒毛膜蛋白被鉴定为卵黄膜成分）。
