RESUMO
We constructed a bacterial artificial chromosome (BAC)-based physical map of chromosomes 2 and 3 of Drosophila melanogaster, which constitute 81% of the genome. Sequence tagged site (STS) content, restriction fingerprinting, and polytene chromosome in situ hybridization approaches were integrated to produce a map spanning the euchromatin. Three of five remaining gaps are in repeat-rich regions near the centromeres. A tiling path of clones spanning this map and STS maps of chromosomes X and 4 was sequenced to low coverage; the maps and tiling path sequence were used to support and verify the whole-genome sequence assembly, and tiling path BACs were used as templates in sequence finishing.
Assuntos
Mapeamento de Sequências Contíguas , Drosophila melanogaster/genética , Genoma , Animais , Centrômero/genética , Cromatina/genética , Cromossomos Bacterianos/genética , Clonagem Molecular , Impressões Digitais de DNA , Eucromatina , Biblioteca Gênica , Genes de Insetos , Marcadores Genéticos , Vetores Genéticos , Hibridização In Situ , Sequências Repetitivas de Ácido Nucleico , Mapeamento por Restrição , Análise de Sequência de DNA , Sitios de Sequências Rotuladas , Telômero/genéticaRESUMO
A moderate resolution single nucleotide polymorphism (SNP) map of the genome of Drosophila melanogaster that is designed for use in quantitative genetic mapping is described. Seventeen approximately 500 nucleotide gene sequences spaced at 10 to 20 centimorgan intervals were combined with 49 shorter sequence tag sites (STSs) at 5 to 10 centimorgan intervals to generate a map that should not leave any gaps greater than one half of a chromosome arm when any two wild type lines are compared. Of 20 markers with sufficient polymorphism to construct haplotype cladograms, 13 showed evidence for two divergent classes of haplotype. The possible mechanisms for and implications of the unexpected finding that two thirds of all short gene sequences in D. melanogaster may be dimorphic are discussed, including the suggestion that admixture between two separate lineages may have been a major event in the history of the species.
Assuntos
Drosophila melanogaster/genética , Genoma , Polimorfismo de Nucleotídeo Único/genética , Animais , Sequência de Bases , Haplótipos/genética , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNARESUMO
For nearly a century, genetic analysis in Drosophila melanogaster has been a powerful tool for analyzing gene function, yet Drosophila lacks the molecular genetic mapping tools that recently have revolutionized human, mouse, and plant genetics. Here, we describe the systematic characterization of a dense set of molecular markers in Drosophila by using a sequence tagged site-based physical map of the genome. We identify 474 biallelic markers in standard laboratory strains of Drosophila that span the genome. Most of these markers are single nucleotide polymorphisms and sequences for these variants are provided in an accessible format. The average density of the new markers is one per 225 kb on the autosomes and one per megabase on the X chromosome. We include in this survey a set of P-element strains that provide additional use for high-resolution mapping. We show one application of the new markers in a simple set of crosses to map a mutation in the hedgehog gene to an interval of <1 Mb. This new map resource significantly increases the efficiency and resolution of recombination mapping and will be of immediate value to the Drosophila research community.