BAC Libraries for Fundamental Studies in Lepidoptera

University Of Rhode Island, Kingston RI

Investigators

Abstract

0208388 Goldsmith The goal of this proposal is to build a public facility for distribution of BAC libraries for accelerated research in development and evolution for a set of well-established lepidopteran insect models in two key areas: 1) developmental and functional neurobiology and 2) the genetic and developmental basis of adaptation. Readily available BAC libraries for these species will accelerate research into the genetic mechanisms underlying lepidopteran development, behavior, morphology, and evolution. Specific objectives of the research and how they will be achieved are: 1. To produce 6 high-quality BAC libraries for three different experimentally important lepidopteran species. In order to achieve complementary overlaps and deep genome coverage, two BAC libraries equivalent to 10X genome coverage will be made for each species by partial digestion of high molecular weight DNA using one of two enzymes that recognizes different base composition restriction sites and arrayed in 384-well microplates. 2. To characterize each library for percentage of insert-empty clones, average insert size, insert size distribution, clone stability, and cytoplasmic contamination to ensure high library quality. 3. To assess true genome coverage and provide preliminary comparative genome data by screening each library with a set of well-conserved gene sequences. 4. To maintain, archive and disseminate the libraries to the public on a cost-recovery basis through the Texas A and M University GENEfinder Genomic Resources, one of the largest genomic resource centers in the world. The species were chosen primarily for their centrality as experimental models for a wide range of research problems. They are: 1. a Sphingid moth, the tobacco hornworm, Manduca sexta, which is a model for developmental mechanisms, neurobiology, cell biology, physiology, chemical communication, and hostplant selection studied by a large international community 2. a Noctuid moth, the tobacco budworm, Heliothis virescens, a genetically tractable member of a widespread group of largely agricultural pests used as a model for investigating genes that change under differential selection, such as resistance to chemical and biological pesticides 3. a Heliconid butterfly, Heliconius erato, which is a classic model for mullerian mimicry and convergent evolutionary change. The first fruits of the BAC libraries proposed here will be to provide a set of conserved anchor loci that will serve as a framework to unify genetic studies in the Lepidoptera and to investigate phylogenetic relationships, which are still largely unresolved for most of the clade. For the long term, the construction of a set of lepidopteran BAC libraries will provide critically important tools for every aspect of insect science, especially for comparative genomics and future sequencing of model genomes. It will also provide new insights into long-held questions such as 1) how development constrains evolution, 2) the extent to which patterning loci are reused in evolution, and 3) what kinds of developmental changes are preferred by evolution, as well as how they vary across diverse butterfly lineages and different selective landscapes.