Histopathological Effects of the Yen-Tc Toxin Complex from Yersinia entomophaga MH96 (Enterobacteriaceae) on the Costelytra zealandica (Coleoptera: Scarabaeidae) Larval Midgut
| Autor: | Sandra C. Jones, Mark R. H. Hurst, Duane P. Harland, Michelle C. Hares, Lincoln A. Harper, James R. Vernon, Trevor A. Jackson, Sean D. G. Marshall |
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| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Programmed cell death
media_common.quotation_subject Bacterial Toxins Insect Yersinia medicine.disease_cause Applied Microbiology and Biotechnology Microbiology Lepidoptera genitalia Microscopy Electron Transmission medicine Invertebrate Microbiology Animals Humans media_common Ecology Costelytra zealandica biology Toxin Midgut biology.organism_classification Enterobacteriaceae Coleoptera Larva Caco-2 Cells Digestive System Food Science Biotechnology |
| Popis: | Yersinia entomophaga MH96, which was originally isolated from the New Zealand grass grub, Costelytra zealandica , produces an orally active proteinaceous toxin complex (Yen-Tc), and this toxin is responsible for mortality in a range of insect species, mainly within the Coleoptera and Lepidoptera. The genes encoding Yen-Tc are members of the toxin complex (Tc) family, with orthologs identified in several other bacterial species. As the mechanism of Yen-Tc activity remains unknown, a histopathological examination of C. zealandica larvae was undertaken in conjunction with cultured cells to identify the effects of Yen-Tc and to distinguish the contributions that its individual subunit components make upon intoxication. A progressive series of events that led to the deterioration of the midgut epithelium was observed. Additionally, experiments using a cell culture assay system were carried out to determine the cellular effects of intoxication on cells after topical application and the transient expression of Yen-Tc and its individual components. While observations were broadly consistent with those previously reported for other Tc family members, some differences were noted. In particular, the distinct stepwise disintegration of the midgut shared features associated with both apoptosis and necrotic programmed cell death pathways. Second, we observed, for the first time, a contribution of toxicity from two chitinases associated with the Yen-Tc complex. Our findings were suggestive of the activities encoded within the subunit components of Yen-Tc targeting different sites along putative programmed cell death pathways. Given the observed broad host range for Yen-Tc, these targeted loci are likely to be widely shared among insects. |
| Databáze: | OpenAIRE |
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