Presentation Detail

Speciation

Wadsworth, Crista [1], Dopman, Erik [1].

The molecular genetic basis of seasonal asynchrony of the European Corn Borer (Ostrinia nubilalis).

Speciation is the driving force behind evolution, and results in the vast varieties of species seen on this planet today. Using an invasive moth pest, the European Corn Borer (ECB), this study focuses on seasonal asynchrony. We are interested in addressing the molecular mechanisms responsible for this reproductive barrier. In ECB there are two distinct phenotypes for post-diapause developmenttime (PDD), which is the time it takes a diapausing caterpillar to pupate once they have received a specific diapause-breaking cue. For insects in upstate NY, PDD long strain ECB remain in PDD for 44 days and PDD short strain ECB remain in PDD for 14 days. This difference alters the life histories between the strains and results in different voltinism patterns seen in the field, with the PDD long strain being univoltine and the PDD short strain being bivoltine. Differential PDD acts as a prezygotic reproductive barrier and reduces gene flow by up to 85% in sympatric populations. In this study we seek to, 1) use metabolism as a biomarker to isolate days in PDD that the two strains show major physiological differences, 2) ask if the shapes of the metabolic trajectories can tell us about the mechanism controlling differential PDD, and 3)use transcriptome sequencing to quantify differential expression of genes between the strains in a time course during PDD. We address, what the molecular basis of diapause termination and maintenance is in Lepidoptera, what candidate genes are responsible for a "switch" that leads to divergent seasonal timing, and we identify conserved pathways that are present in other taxonomic groupings and different diapause strategies. Ultimatley this research can help us to understand how organisms adapt to changing seasonal conditions which is extrodinarily important in our warming planet of today.

1 - Tufts University, Biology, 200 Boston Ave , Suite 4700, Medford, MA, 02155, USA

Keywords:
Speciation
transcrimptomics
next-generation sequencing
reproductive isolation
lepidopteran
agricultural pest
seasonal timing
diapause
seasonal asynchrony.

Presentation Type: Regular Oral Presentation
Session: 122
Location: Cotton C/Snowbird Center
Date: Tuesday, June 25th, 2013
Time: 8:30 AM
Number: 122001
Abstract ID:31
Candidate for Awards:W.D. Hamilton Award for Outstanding Student Presentation