Michael P. Kambysellis - US grants

The Hawaiian Islands with their populations of endemic Drosophila species provide an ideal natural laboratory for studying evolution and ecological adaptations. The vitellogenin or yolk protein genes of these diverse Hawaiian flies comprise an exceptional model system for analyzing mechanisms and rates of gene evolution in higher organisms. The members of this gene cluster, encoding three vitellogenin proteins, are subject to strict developmental regulation, which controls timing, tissue- specificity and rates of vitellogenin synthesis to coordinate egg maturation of each species with its particular ecological habitat. The proposed research will use the most recently developed techniques of molecular biology to expedite determination of DNA sequences of these genes in nine species and assay levels of sequence variation within and between populations of two species. DNA sequence comparisons will identify the molecular basis of interspecific differences in vitellogenin gene structure and function. Gene changes between species will be related to adaptive shifts in host plants and reproductive strategies, the goal being to distinguish the roles played by various types of DNA sequences in species evolution. Comparisons of phylogenies constructed using divergence in coding versus control sequences will test the hypothesis that regulatory changes in the genome are more closely aligned with adaptive and phylogenetic change.

9317097 Kambysellis Craddock This award supports collaboration between Michael Kambysellis, New York University, and Peng Tongxu, Guangdong Entomological Institute, on the evolution of Chinese Drosophila and the comparison of the biology of island endemic species (Hawaii) with species endemic to continents. This will be a multiyear collaboration with part of the work being carried out in Guangzhou and part in New York. The collaborative arrangements will provide the opportunity to examine the speciose Chinese Drosophila fauna and make comparisons to the extraordinary drosophila fauna of the Hawaiian Island. This work contributes to the current worldwide efforts to understand and catalogue global biodiversity. The project will involve participation of graduate students in both China and the United States.

9505535 Kambysellis Dr. Kambyselis requests funds for a small Grant for Exploratory Research (SGER). The project aims to develop an experimental methodology whereby specific genes can be transferred from the genome of one Drosophila species into another, without the use of genetic markers in the recipient species as traditionally required for such genetic manipulations. Whereas there is a vast array of genetic mutants available for the species Drosophila melanogaster, most other Drosophila species of interest to evolutionary and developmental biologist lack available mutants, limiting their genetic analysis. To rectify this situation and facilitate analysis of gene expression and the evolution of gene regulation in the endemic Hawaiian Drosophila and other groups, novel vectors using as markers neomycin resistance or the green fluorescent protein will be developed to establish a transformation system applicable to any Drosophila species. The successful development of this methodology will have broad application, facilitating genetic analyses of basic phenomena such as behavior, evolution, and the role of pattern formation is development, as examples. Even wider application may ensure if the general approach of transgenic insect formation can subsequently be extended to insects of economic importance, enabling novel approaches to agricultural problems.

9707869 KAMBYSELLIS Fruit flies (family Drosophilidae) have been used for more than a century as model systems to explore major issues in biological and environmental sciences. The Hawaiian Drosophilidae, an assemblage of about a thousand species, represent the premier example of founder-effect speciation and adaptive radiation on oceanic islands, but except for the picture-winged cluster of about 100 species, their taxonomy and systematics are poorly known. In this collaborative project, the systematic biology of the Hawaiian drosophilids will be reviewed, and a robust phylogeny reconstructed. The work will include field collections, descriptions of species, establishment of cultures, and collections of morphological, molecular and behavioral characters for phylogenetic analysis. The resulting analysis is expected to be definitive, and to support future analyses of developmental and behavioral pathways in these flies.