Collaborative Research: The Evolution of Patterning Mechanisms Within Arthropod Limbs

University Of Arizona, Tucson AZ

Investigators

Abstract

0236193 Nagy Arthropods can be found in virtually every habitat on earth - a radiation driven in large part by the diverse specializations of their limbs. In spite of the enormous variability in limb structures, the initial comparative studies of genes that pattern limbs have emphasized conserved patterns of gene expression. Perhaps this is because similarities to the model system (Drosophila) are more easily explicable than differences. However, Drs. Nagy and Williams seek to understand the morphological diversification of arthropod limbs. To this end, they propose a series of experiments to dissect the function of both genes whose expression varies from the known Drosophila pattern and ones whose expression is conserved. They use the insect- crustacean clade for this analysis since crustaceans have extremely diverse limb morphologies, while insects have the best studied molecular mechanisms of limb formation. Their goal is to uncover mechanisms underlying the generation of morphological diversity among insect-crustacean limbs. They approach this goal using both descriptive, genetic and experimental studies on a variety of species. Because these studies involve a number of both insect and crustacean species, they provide a framework for inferences as to the ancestral patterning circuitry for the insect/crustacean lineage. In addition, because they evaluate function in both conserved and varying genes, these studies will be informative about how a similar set of genes has been redeployed throughout evolution. Broader impact: This project promotes education at multiple levels of inquiry. Some of the proposed work forms the basis of graduate training; other aspects will form undergraduate research projects. Continued analysis of results from the previously funded project will become an online lesson plan in genetics and development, created in a high school teacher education program. The results of our research will be published in scientific journals and regularly presented at local, national and international meetings and discussed in undergraduate classes, seminars, and online discussion sections. The arthropods maintained in laboratory culture provide a much needed resource to local pre- and elementary schools and high school science classes.