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Silkworm salivary glands are not susceptible to Bombyx mori nuclear polyhedrosis virus
L A Dourado1, L F C Ribeiro, R M C Brancalhão
1Laboratório de Organização Funcional do Núcleo, Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Maringá, PR, Brasil.
Abstract:
A nuclear polyhedrosis virus isolated from infected Bombyx mori, BmNPV, was used to inoculate silkworms to determine salivary gland cell susceptibility. The salivary gland was removed from infected silkworms at different times post-inoculation and examined by light microscopy. The salivary gland cells did not exhibit any signs of BmNPV infection; however, fat body and tracheal cells, used as positive controls, showed characteristic cytopathological changes caused by BmNPV infection, which confirmed inoculum viability. The morphological distribution of tracheal branches and the basal lamina, which serves as a barrier to viral penetration, are apparently involved in this resistance to infection.
Insights
Bombyx mori nuclear polyhedrosis virus (BmNPV) did not infect silkworm salivary glands. Tracheal branches and basal lamina appear to prevent BmNPV infection in these tissues.
Area of Science:
- Virology
- Insect Pathology
- Molecular Biology
Background:
- Nuclear polyhedrosis viruses (NPVs) are significant pathogens of insects.
- Bombyx mori nuclear polyhedrosis virus (BmNPV) is a well-studied baculovirus.
- Understanding tissue tropism is crucial for viral pathogenesis research.
Purpose of the Study:
- To investigate the susceptibility of Bombyx mori salivary gland cells to BmNPV infection.
- To identify potential barriers to BmNPV infection in silkworm tissues.
Main Methods:
- Inoculation of silkworms with BmNPV.
- Collection of salivary glands at various time points post-inoculation.
- Examination of salivary glands using light microscopy.
- Utilizing fat body and tracheal cells as positive controls.
Main Results:
- Silkworm salivary gland cells showed no cytopathological signs of BmNPV infection.
- Positive control tissues (fat body and tracheal cells) exhibited characteristic BmNPV-induced changes.
- Inoculum viability was confirmed by positive control infections.
- Tracheal branch morphology and the basal lamina were identified as potential factors in salivary gland resistance.
Conclusions:
- Silkworm salivary glands are resistant to BmNPV infection.
- The physical structure of tracheal branches and the basal lamina may act as barriers to viral entry.
- Further research is needed to elucidate the precise mechanisms of BmNPV resistance in salivary glands.
