SGER: Spontaneous Mutation in the Moth, Heliothis virescens

Michigan State University, East Lansing MI

Investigators

Abstract

Genetic mutation can be caused by external mutagenic agents such as chemical mutagens or radiation, or it can occur without the impact of external agents. Natural mutagenesis due to transposable elements is understood primarily from research in fruit flies; it results when a gene is affected by the movement of another gene causing a change in phenotype. Activity of a Mariner element was observable in Drosophila mauritiana as a high frequency of mosaicism or speckling in the eye controlled by the Mos1 gene (Hartl, 2001). Although it appears that many transposable elements have become silenced leaving an inactive sequence in the host genome, the mechanism of regulation is not understood. There are few models of natural mutagenesis apart from those in fruit flies. The objective of this project is to develop a new genetic model for natural mutagenesis, focusing on understanding the mechanism by which multiple spontaneous mutations of pigmentation (black eye, golden eye, et al.) and patterning (striped eye) arose in a lineage of a moth, Heliothis virescens (Lepidoptera: Noctuidae). While there are many possible mechanisms for this phenomenon, this project will focus on one working hypothesis that each of the various phenotypes is controlled by mutation in a corresponding gene. Each putative gene will be purified while gathering physiological data on mechanisms of altered pigmentation so that the mutations and any novel genetic mechanism involved can be identified subsequently. This project bears the risks of disproving the stated hypothesis; however, in that case this approach will provide information applicable to an alternate hypothesis. The significance of discovering a new type of natural mutagenesis if present will be in advancing the basic science of eukaryotic genetics leading to scientific applications to benefit society. Examples of present and anticipated applications of understanding mutation include defense against genetic weapons and genetic control of mosquitoes and other pests.