Evolutionary Relationships in the Drosophila ananassae Species Cluster Based on Introns of Multiple Nuclear Loci

The Drosophila ananassae species cluster includes D. ananassae, D. pallidosa, D. parapallidosa, and the cryptic species “pallidosa-like”, “pallidosa-like Wau” and “papuensis-like” Some of the taxa are sympatric in the South Pacific, Papua New Guinea, and Southeast Asia, and gene flow between different taxa has been suspected for a handful of genes. In the present analysis, we examined DNA sequences of introns in four loci: alpha actinin (Actn) on XL, white (w) on XR, CG7785 on 2L, and zinc ion transmembrane transporter 63C (ZnT63C) on 2R. Phylogenetic trees (neighbor-joining and haplotype network) were inconsistent among these loci. Some haplotypes shared between taxa were found for w, CG7785, and ZnT63C, suggesting recent gene flow. However, no haplotypes were shared, for example, between D. ananassae and D. pallidosa for CG7785, which is close to the proximal breakpoint of In(2L)D. This suggests that taxon-specific inversions prevent gene flow, as predicted by the chromosomal speciation hypothesis

アナナスショウジョウバエ亜群の染色体変異と類縁関係

Gene arrangements of 854 isofemale lines of D. ananassae collected from 39 localities ranging from Africa, India, Southeast Asia, Japan, Micronesia, Melanesia, and Polynesia to South America were investigated. In order to determine the breakpoint of inversions and translocations, a revised photomap of the polytene chromosome was prepared. A total of 52 paracentric inversions, 7 pericentric inversions and one translocation were detected. Three cosmopolitan inversions of D. ananassae, In(2L)A, In(3L)A, and In(3R)A, were found in most of the localities surveyed and no appreciable geographical divergence was found in the composition of inversions, although some inversions were restricted in their distribution to particular localities. However, the three reproductively isolated populations have been inhabiting in the same locality of Papua New Guinea were found: the first one is the cosmopolitan form of ananassae, the second one is papueftsis-like similar to the population proposed by Futch (1966) as a new species ("paptcensis"), and the third one is pallidosa-like. In Kota Kinabalu, Malaysia, we found a reproductively isolated population which is considered to be a new taxon. Using overlapping inversions we propose the phylogenetic relationship of the chromosome arrangements of D. ananassae and its close relatives.東京都立大学, 1993-02-18, 博士（理学）, 乙第809号

Polytene Chromosomal Maps of 11 Drosophila Species: The Order of Genomic Scaffolds Inferred From Genetic and Physical Maps

The sequencing of the 12 genomes of members of the genus Drosophila was taken as an opportunity to reevaluate the genetic and physical maps for 11 of the species, in part to aid in the mapping of assembled scaffolds. Here, we present an overview of the importance of cytogenetic maps to Drosophila biology and to the concepts of chromosomal evolution. Physical and genetic markers were used to anchor the genome assembly scaffolds to the polytene chromosomal maps for each species. In addition, a computational approach was used to anchor smaller scaffolds on the basis of the analysis of syntenic blocks. We present the chromosomal map data from each of the 11 sequenced non-Drosophila melanogaster species as a series of sections. Each section reviews the history of the polytene chromosome maps for each species, presents the new polytene chromosome maps, and anchors the genomic scaffolds to the cytological maps using genetic and physical markers. The mapping data agree with Muller's idea that the majority of Drosophila genes are syntenic. Despite the conservation of genes within homologous chromosome arms across species, the karyotypes of these species have changed through the fusion of chromosomal arms followed by subsequent rearrangement events

Evolution of genes and genomes on the Drosophila phylogeny

Affiliations des auteurs : cf page 216 de l'articleInternational audienceComparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species

Evolution of genes and genomes on the Drosophila phylogeny

Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species