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
The fly Drosophila melanogaster is one of the most intensively studied organisms in biology and serves as a model system for the investigation of many developmental and cellular processes common to higher eukaryotes, including humans. We have determined the nucleotide sequence of nearly all of the approximately 120-megabase euchromatic portion of the Drosophila genome using a whole-genome shotgun sequencing strategy supported by extensive clone-based sequence and a high-quality bacterial artificial chromosome physical map. Efforts are under way to close the remaining gaps; however, the sequence is of sufficient accuracy and contiguity to be declared substantially complete and to support an initial analysis of genome structure and preliminary gene annotation and interpretation. The genome encodes approximately 13,600 genes, somewhat fewer than the smaller Caenorhabditis elegans genome, but with comparable functional diversity.
Assuntos
Drosophila melanogaster/genética , Genoma , Análise de Sequência de DNA , Animais , Transporte Biológico/genética , Cromatina/genética , Clonagem Molecular , Biologia Computacional , Mapeamento de Sequências Contíguas , Sistema Enzimático do Citocromo P-450/genética , Reparo do DNA/genética , Replicação do DNA/genética , Drosophila melanogaster/metabolismo , Eucromatina , Biblioteca Gênica , Genes de Insetos , Heterocromatina/genética , Proteínas de Insetos/química , Proteínas de Insetos/genética , Proteínas de Insetos/fisiologia , Proteínas Nucleares/genética , Biossíntese de Proteínas , Transcrição GênicaRESUMO
We describe here our experience in annotating the Drosophila melanogaster genome sequence, in the course of which we developed several new open-source software tools and a database schema to support large-scale genome annotation. We have developed these into an integrated and reusable software system for whole-genome annotation. The key contributions to overall annotation quality are the marshalling of high-quality sequences for alignments and the design of a system with an adaptable and expandable flexible architecture.