Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/27/2007
Publication Date: 9/1/2008
Citation: Harrison, R.L., Lynn, D.E. 2008. New cell lines derived from the black cutworm, Agrotis ipsilon, that support replication of the A. ipsilon multiple nucleopolyhedrovirus and several group I nucleopolyhedroviruses. Journal of Invertebrate Pathology. 99:28-34. Interpretive Summary: Insects, such as the black cutworm, cause billions of dollars of damage to crops each year. The use of chemical insecticides to control insect pests can have negative ecological, environmental, and health consequences. Biological pest control agents such as insect viruses can be effective alternatives and are generally safer but are also more expensive and difficult to produce. In this study, we have established two new cell lines from the black cutworm. We have also shown that these cell lines are susceptible to various insect viruses which are potential biological control agents. Researchers at universities, government and commercial laboratories that are involved in developing these viruses as alternatives to chemical pesticides can use these cell lines for the development of these and other biological pest control agents.
Technical Abstract: New cell lines were recently developed from the embryos of the black cutworm, Agrotis ipsilon (Lepidoptera: Noctuidae). A primary culture was initiated from 4 day-old A. ipsilon eggs in ExCell420 medium supplemented with 5% fetal bovine serum. This initial culture produced sufficient cell growth to allow subcultivation and eventually led to the establishment of 8 distinct strains. Two of these strains (AiE1611T and AiEd6T) were selected for further characterization. Extracts of these strains were compared to an extract from A. ipsilon eggs by isozyme analysis and shown to be from the same species. Both strains were susceptible to infection by the Agrotis ipsilon multiple nucleopolyhedrovirus (AgipMNPV), as well as to lepidopteran group I NPVs from Autographa californica, Anagrapha falcifera, Anticarsia gemmatalis, Galleria mellonella, Helicoverpa armigera, Plutella xylostella, and Rachiplusia ou, with large numbers of occlusion bodies produced in most of the inoculated cells. The cell lines did not support the replication of group II NPVs from Helicoverpa zea, Lymantria dispar, and Spodoptera exigua. Both cell lines produced confluent monolayers in plaque assays and supported the formation of plaques upon infection with AgipMNPV and Autographa californica (Ac)MNPV. Twenty AgipMNPV plaques were picked from either AiE1611T or AiEd6T monolayers, and the plaque isolates were serially passaged three times through A. ipsilon cells. Only one isolate from AiE1611T cells exhibited genotypic variation in the form of an altered restriction fragment profile. Our results suggest these new lines can be useful in the study of AgipMNPV and A. ipsilon cellular and molecular biology.