Soares José S, Ribeiro Bergmann M
Laboratory of Electron Microscopy and Virology, University of Brasília, Brasília, DF, CEP 70910-900, Brazil.
Res Microbiol. 2005 Mar;156(2):263-9. doi: 10.1016/j.resmic.2004.09.015. Epub 2004 Dec 15.
Light and stereomicroscopy examinations of Anticarsia gemmatalis multicapsid nucleopolyhedrovirus (AgMNPV)-infected insects were performed in order to follow infection in its host, A. gemmatalis. Fourth-instar A. gemmatalis larvae were infected by administration of occluded virus (polyhedra) from two recombinant AgMNPV viruses (vAgEGTDelta-lacZ or vAgGalA2) directly into the larvae foregut. The recombinant virus vAgEGTDelta-lacZ has the beta-galactosidase gene (lac-Z) of Escherichia coli under the control of a constitutive promoter (hsp70 from Drosophila melanogaster). The vAgGalA2 virus has the reporter gene lac-Z under the control of the AgMNPV very late polyhedrin gene promoter. At different times post-infection (p.i.) the infected larvae were dissected, fixed, and the product of the expression of the lac-Z gene detected by incubating the insects in a buffer containing X-gal. This allowed us to follow the infection through the blue cells (due to the degradation of X-gal by the enzyme Lac-Z). Insect larvae inoculated with polyhedra from the recombinant viruses showed midgut cells to be infected first, followed by tracheal cells, hemolymph, fat body, Malpighian tubules and brain cells. The infection was similar for the two recombinant viruses, with blue cells appearing earlier in insects infected with the vAgEGTDelta-lacZ virus when compared to the vAgGalA2 virus.
为了追踪苜蓿银纹夜蛾多核衣壳核型多角体病毒（AgMNPV）在其宿主苜蓿银纹夜蛾中的感染情况，对感染该病毒的昆虫进行了光学显微镜和体视显微镜检查。将来自两种重组AgMNPV病毒（vAgEGTDelta-lacZ或vAgGalA2）的包涵体病毒（多角体）直接注入四龄苜蓿银纹夜蛾幼虫的前肠，使其感染。重组病毒vAgEGTDelta-lacZ在组成型启动子（来自黑腹果蝇的hsp70）控制下具有大肠杆菌的β-半乳糖苷酶基因（lac-Z）。vAgGalA2病毒的报告基因lac-Z受AgMNPV极晚期多角体蛋白基因启动子控制。在感染后不同时间（p.i.），解剖并固定感染的幼虫，通过将昆虫置于含有X-gal的缓冲液中孵育来检测lac-Z基因表达产物。这使我们能够通过蓝色细胞（由于Lac-Z酶降解X-gal所致）追踪感染情况。接种重组病毒多角体的昆虫幼虫显示，中肠细胞首先被感染，随后是气管细胞、血淋巴、脂肪体、马氏管和脑细胞。两种重组病毒的感染情况相似，与vAgGalA2病毒相比，感染vAgEGTDelta-lacZ病毒的昆虫中蓝色细胞出现得更早。
