Active Research Evolutionary genomics of Drosophila Genetic diversity of P. falciparum Evolution of hybrid incompatibilities Evolution of gene expression Natural selection and protein evolution   Past Research Evolution of novel gene functions Bioinformatics Selective sweep C-value paradox Transposable element mariner Structure and sequence of the Drosophila genome Genome structure and evolution in D. virilis Cosuppression of transposable elements Molecular evolution in enteric bacteria Gregor Mendel

Genome structure and evolution in Drosophila virilis Comparisons between the physical maps of divergent species can be used to identify conserved blocks of closely linked genes whose synteny is possibly under selective constraint. We used in situ hybridization to determine the genomic position of 732 randomly selected clones from a bacteriophage P1 library of D. virilis. The resulting map included at least one clone in each of 69 percent of the subdivisions into which the D. virilis polytene chromosomes are divided. A subset of ~100 of these clones was used to carry out a comparative analysis of D. virilis, D. montana, and D. novamexicana. The data indicated that, in the virilis species group, the X chromosome has up to four times the number of rearrangements as are observed in chromosome 3. Detailed chromosomal analysis also revealed extensive rearrangements have occurred in the chromosome arms in the evoution of D. virilis and D. melanogaster.     Vieira, C. P., J. Vieira and D. L. Hartl, 1997 The evolution of small gene clusters: Evidence for an independent origin of the maltase gene cluster in D. virilis and D. melanogaster. Mol. Biol. Evol. 14: 985-993.       Vieira, J., C. P. Vieira, D. L. Hartl and E. R. Lozovskaya, 1997 Discordant rates of chromosome evolution in the Drosophila virilis species group. Genetics 147: 223-230.     PDF Vieira, J., C. P. Vieira, D. L. Hartl and E. R. Lozovskaya, 1997 A framework physical map of Drosophila virilis based on P1 clones: Applications in genome evolution. Chromosoma 106: 99-107.       Hartl, D. L. and E. R. Lozovskaya, 1994 Genome evolution: Between the nucleosome and the chromosome, pp. 579-592 in B. Schierwater, B. Streit, G. P. Wagner, and R. DeSalle (editors) Molecular Ecology and Evolution: Approaches and Applications, Birkhauser Verlag, Basel.       Lozovskaya, E. R., D. A. Petrov and D. L. Hartl, 1993 A combined molecular and cytogenetic approach to genome evolution in Drosophila using large-fragment DNA cloning. Chromosoma 102: 253-266.