Yazaki K, Miura K
Hepatitis Division, Tokyo Metropolitan Institute of Medical Science, Honkomagome, Bunkyo-ku, Tokyo, 113, Japan.
Virology. 1980 Sep;105(2):467-79. doi: 10.1016/0042-6822(80)90047-1.
Cytoplasmic polyhedrosis virus (CPV) was observed under an electron microscope using a combination of staining and shadowing methods. Projections, not only in positions horizontal to the grid but also vertical, were clearly visualized. When the particle was mildly disrupted with EDTA, genome dsRNA was released from a projection. If the particle was previously fixed with glutaraldehyde and then disrupted, dsRNA was released with a protein particle, which seemed to correspond to the base part of the projection. The protein particle was in most cases at the end of the strand, which sometimes takes a supercoiled structure. When CPV was incubated during mRNA synthesis, the protein particles appeared in various positions along the strands, and loop formations of dsRNA appeared. From these observations, we suggest that transcription in this virus particle proceeds as follows: genome dsRNA is transcribed by passing through the base part of the projection, where the enzymes for mRNA synthesis are located. A completed mRNA is released from the virion at the projection.
利用染色和投影法相结合的方式，在电子显微镜下观察细胞质多角体病毒（CPV）。不仅在与网格水平的位置，而且在垂直位置的突起都清晰可见。当用乙二胺四乙酸（EDTA）对病毒颗粒进行轻度破坏时，基因组双链RNA（dsRNA）从一个突起处释放出来。如果病毒颗粒事先用戊二醛固定，然后再破坏，双链RNA会与一个蛋白质颗粒一起释放出来，这个蛋白质颗粒似乎对应于突起的基部。蛋白质颗粒在大多数情况下位于链的末端，链有时呈超螺旋结构。当CPV在mRNA合成过程中进行孵育时，蛋白质颗粒沿链出现在不同位置，并且出现双链RNA的环状结构。从这些观察结果来看，我们认为该病毒颗粒中的转录过程如下：基因组双链RNA通过位于突起基部的mRNA合成酶所在位置进行转录。完整的mRNA在突起处从病毒粒子中释放出来。
