Submitted to: PLoS One
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/12/2012
Publication Date: 2/27/2012
Publication URL: http://handle.nal.usda.gov/10113/55771
Citation: Valles, S.M., Oi, D.H., Yu, F., Tan, X., Buss, E.A. 2012. Metatranscriptomics and pyrosequencing facilitate discovery of potential viral natural enemies of the invasive Caribbean crazy ant, Nylanderia pubens. PLoS One. 7(2):1-9. Interpretive Summary: The exotic and invasive ant known as the Caribbean crazy ant (CCA), Rasberry crazy ant, or the hairy crazy ant, inundates structures, landscapes, and natural areas. Their sheer numbers result in incessant complaints, electrical malfunctions, and crop damage from tending of aphids and mealybug pests to causing pollinator honeybees to vacate hives. They are well established in Florida and Texas, and are spreading to other southern states. Effective methods to reduce populations and mitigate their spread are urgently needed. Scientists at the USDA-ARS Center for Medical, Agricultural, and Veterinary Entomology and the University of Florida, Entomology and Nematology Department sequenced the transcriptome of CCA populations from various regions in Florida in an effort to identify pathogens for possible use in controlling the ant. Analyses of over 1.3 million raw gene sequences yielded 5 sequences that were likely of viral origin. This is the first step toward identifying and utilizing biological control agents for self-sustaining suppression of CCA. In addition, the transcriptome of this ant generated from this study, provides a genetic resource that is especially important for developing a knowledgebase for this invasive pest.
Technical Abstract: Background: Nylanderia pubens (Forel) is an invasive ant species that in recent years has developed into a serious nuisance problem in the Caribbean and United States. A rapidly expanding range, explosive localized population growth, and control difficulties have elevated this ant to pest status. Professional entomologists and the pest control industry in the United States are scrambling to understand its biology and develop effective control methods. Currently, no known biological-based control agents are available for use in controlling N. pubens. Methodology and Principal Findings: Metagenomics and pyrosequencing techniques were employed to examine the transcriptome of field-collected N. pubens colonies in an effort to identify virus infections with potential to serve as control agents against this pest ant. The 454 pyrosequencing of a non-normalized N. pubens expression library generated 1,306,177 raw sequence reads comprising 450 Mbp. Assembly resulted in generation of 59,017 non-redundant sequences, including 27,348 contigs and 31,669 singlets. BLAST analysis of these non-redundant sequences yielded 51 sequences of potential viral origin. Additional analyses winnowed this list of potential viruses to 3 that appear to replicate in N. pubens. Conclusions: Pyrosequencing the transcriptome of field-collected samples of N. pubens has identified at least 3 sequences that are likely of viral origin and, in which, N. pubens serves as host. In addition, the N. pubens transcriptome provides a genetic resource for the scientific community which is especially important at this early stage of developing a knowledgebase for this new pest.