Submitted to: PLoS One
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/7/2013
Publication Date: 5/1/2013
Citation: Sparks, M., Blackburn, M.B., Kuhar, D.J., Gundersen, D.E. 2013. Transcriptome of the lymantria dispar (gypsy moth) larval midgut and its response to infection by bacillus thuringiensis. PLoS One. 8(5):e61190. Interpretive Summary: The gypsy moth (Lymantria dispar) is a serious insect pest of hardwood and shade trees in the Northeast United States, costing millions of dollars annually in damage and control costs. Very little genetic information has been generated for gypsy moth even though this information would help scientists devise new biological control strategies that may slow the spread of the gypsy moth. In order to analyze the total genetic components (called the “transcriptome”) produced by the insect, we examined gypsy moth midgut tissues in healthy caterpillars and in caterpillars infected with bacteria called Bacillus thuringiensis that is commonly used as a biological pesticide. We generated new genetic information for the gypsy moth caterpillar pest that will be publicly accessible. We found numerous candidate genetic components associated with the gypsy moth pest that could represent new targets for biological control strategies or could give us information about resistance development by gypsy moth caterpillars in the environment. This information will be of interest to scientists and biopesticide companies that are interested in developing new or molecule-based strategies towards control of gypsy moth.
Technical Abstract: Transcriptomic profiles of the serious lepidopteran insect pest Lymantria dispar (gypsy moth) were characterized in the larval midgut in response to infection by Bacillus thuringiensis kurstaki, a biopesticide commonly used for its control in nature. RNA-Seq approaches were used to define a set of 49,613 assembled transcript sequences, of which 838, 1,248 and 3,305 were partitioned into high-, mid- and low-quality tiers, respectively, on the basis of homology information. RNA-Seq-based expression profiles were used to suggest genes that may have been differentially expressed in response to infection, which were validated by use of qRT-PCR analysis on distinct genes. Strong down-regulation of genes related to digestion and up-regulation of genes related to antibacterial response, binding, and hormone regulation, as well as several hypothetical protein genes of uncharacterized function. These results suggest important genes that could be involved in biopesticide resistance development or could serve as targets for biologically-based control mechanisms of this insect pest.