Centennial Honors College
Western Illinois University
Undergraduate Research Day 2012
Poster Presentation
The Gene Expression of Caterpillar Midguts after Feeding on Tobacco Plants
Donna James
Faculty Mentor: Richard Musser
Biology
The polyphagous eating habits of the corn earworm, Helicoverpa zea (Boddy), are
underscored by its status as a major agricultural pest with a wide geographic distribution
and host plant repertoire. To study the transcriptomic response to toxins in diet, a
microarray analysis was conducted on 6th instar caterpillars feeding on artificial diet, or
tobacco plants Nicotiana tabacum (L.) plants. The mid-guts of the caterpillars were
dissected from the caterpillars after 24 hours of feeding on the respective treatments
and placed immediately in trizol. Then total RNA was purified, amplified and labeled a
placed onto a caterpillar microarray chip. 1000s of genes were altered in the
transciptome reflecting an abundant expression of proteases, cytochrome P450 and
immune-related genes which are likely in part adaptive to feeding on the more toxic and
more difficult to digest tobacco leaves in comparison to the artificial diet. My study
provides a beginning to understanding the broad regulation of genes associated with
feeding on plants and their defense responses.