title: Cytopathological process by multiple nucleopolyhedrovirus in the testis of Bombyx mori L., 1758 (Lepidoptera: Bombycidae).
abstract: A cytopathological methodology was used to analyze infection by Bombyx mori multiple nucleopolyhedrovirus (BmMNPV), a geographic isolate of the family Baculoviridae, in the caterpillar testes of the B. mori. Japanese B. mori strain caterpillar, fifth instar, were inoculated with BmMNPV and their testes were collected and processed for light and transmission electronic microscopy. Epithelial coating cells and interfollicular septa in testes were susceptible to BmMNPV. The first evidence of infection was detected on the 6th day post-inoculation (p.i.) in the external epithelium, and on the 7th day p.i. in the internal epithelium and interfollicular septa. Cytopathological characteristics consisted of hypertrophied nuclei, the formation of virogenic stroma, and the occlusion of virions in polyhedron protein crystals in several stages of development. At the end of the infectious process, cell lysis and release of polyhedra into the extracellular medium occurred. Histopathology revealed early infection foci in the surrounding regions of tracheal insertions, thus underlining the role of the trachea as an infection-spreading organ in insects. This spreading occurs through penetration of the basal lamina, which facilitates entry of the budded virus into the testis. Additionally, an alignment of a partial sequence of the ORF 14 of the BmMNPV geographic isolate with other NPV certified the virus genera.
authors.affiliation: Departamento de Biologia Celular e Genética, Laboratório de Morfologia e Citogenética de Insetos, Universidade Estadual de Maringá, PR, Brazil.
authors.forename: Eliana Peliçon
authors.initials: EP
authors.lastname: Pereira
authors.forename: Hélio
authors.initials: H
authors.lastname: Conte
authors.forename: Lucinéia de Fátima Chasko
authors.initials: Lde F
authors.lastname: Ribeiro
authors.forename: Daniela Bertolini
authors.initials: DB
authors.lastname: Zanatta
authors.forename: Juliana Pereira
authors.initials: JP
authors.lastname: Bravo
authors.forename: Maria Aparecida
authors.initials: MA
authors.lastname: Fernandez
authors.forename: Rose Meire Costa
authors.initials: RM
authors.lastname: Brancalhão
mesh_terms: D000818:Animals; D012831:Bombyx / Q000502:physiology / Q000821:virology*; D002467:Cell Nucleus / Q000648:ultrastructure / Q000821:virology; D003593:Cytoplasm / Q000648:ultrastructure / Q000821:virology; D004266:DNA Virus Infections / Q000821:virology*; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D015967:Gene Expression Regulation, Viral; D054884:Host-Pathogen Interactions / Q000502:physiology; D008018:Life Cycle Stages / Q000502:physiology; D008297:Male; D046529:Microscopy, Electron, Transmission; D017924:Nucleopolyhedroviruses / Q000472:pathogenicity / Q000502:physiology*; D013737:Testis / Q000473:pathology* / Q000821:virology
chemical_list: D004279:DNA, Viral