RESUMEN
Human chromosome 16 features one of the highest levels of segmentally duplicated sequence among the human autosomes. We report here the 78,884,754 base pairs of finished chromosome 16 sequence, representing over 99.9% of its euchromatin. Manual annotation revealed 880 protein-coding genes confirmed by 1,670 aligned transcripts, 19 transfer RNA genes, 341 pseudogenes and three RNA pseudogenes. These genes include metallothionein, cadherin and iroquois gene families, as well as the disease genes for polycystic kidney disease and acute myelomonocytic leukaemia. Several large-scale structural polymorphisms spanning hundreds of kilobase pairs were identified and result in gene content differences among humans. Whereas the segmental duplications of chromosome 16 are enriched in the relatively gene-poor pericentromere of the p arm, some are involved in recent gene duplication and conversion events that are likely to have had an impact on the evolution of primates and human disease susceptibility.
Asunto(s)
Cromosomas Humanos Par 16/genética , Duplicación de Gen , Mapeo Físico de Cromosoma , Animales , Genes/genética , Genómica , Heterocromatina/genética , Humanos , Datos de Secuencia Molecular , Polimorfismo Genético/genética , Análisis de Secuencia de ADN , Sintenía/genéticaRESUMEN
Chromosome 5 is one of the largest human chromosomes and contains numerous intrachromosomal duplications, yet it has one of the lowest gene densities. This is partially explained by numerous gene-poor regions that display a remarkable degree of noncoding conservation with non-mammalian vertebrates, suggesting that they are functionally constrained. In total, we compiled 177.7 million base pairs of highly accurate finished sequence containing 923 manually curated protein-coding genes including the protocadherin and interleukin gene families. We also completely sequenced versions of the large chromosome-5-specific internal duplications. These duplications are very recent evolutionary events and probably have a mechanistic role in human physiological variation, as deletions in these regions are the cause of debilitating disorders including spinal muscular atrophy.
Asunto(s)
Cromosomas Humanos Par 5/genética , Análisis de Secuencia de ADN , Animales , Composición de Base , Cadherinas/genética , Secuencia Conservada/genética , Duplicación de Gen , Genes/genética , Enfermedades Genéticas Congénitas/genética , Genómica , Humanos , Interleucinas/genética , Datos de Secuencia Molecular , Atrofia Muscular Espinal/genética , Pan troglodytes/genética , Mapeo Físico de Cromosoma , Seudogenes/genética , Sintenía/genética , Vertebrados/genéticaRESUMEN
Chromosome 19 has the highest gene density of all human chromosomes, more than double the genome-wide average. The large clustered gene families, corresponding high G + C content, CpG islands and density of repetitive DNA indicate a chromosome rich in biological and evolutionary significance. Here we describe 55.8 million base pairs of highly accurate finished sequence representing 99.9% of the euchromatin portion of the chromosome. Manual curation of gene loci reveals 1,461 protein-coding genes and 321 pseudogenes. Among these are genes directly implicated in mendelian disorders, including familial hypercholesterolaemia and insulin-resistant diabetes. Nearly one-quarter of these genes belong to tandemly arranged families, encompassing more than 25% of the chromosome. Comparative analyses show a fascinating picture of conservation and divergence, revealing large blocks of gene orthology with rodents, scattered regions with more recent gene family expansions and deletions, and segments of coding and non-coding conservation with the distant fish species Takifugu.
Asunto(s)
Cromosomas Humanos Par 19/genética , Genes/genética , Mapeo Físico de Cromosoma , Empalme Alternativo/genética , Animales , Composición de Base , Secuencia Conservada/genética , Islas de CpG/genética , Evolución Molecular , Duplicación de Gen , Genética Médica , Humanos , Ratones , Datos de Secuencia Molecular , Familia de Multigenes/genética , Seudogenes/genética , Análisis de Secuencia de ADNRESUMEN
Thermobispora bispora (Henssen 1957) Wang et al. 1996 is the type species of the genus Thermobispora. This genus is of great interest because it is strictly thermophilic and because it has been shown for several of its members that the genome contains substantially distinct (6.4% sequence difference) and transcriptionally active 16S rRNA genes. Here we describe the features of this organism, together with the complete genome sequence and annotation. This is the second completed genome sequence of a member from the suborder Streptosporangineae and the first genome sequence of a member of the genus Thermobispora. The 4,189,976 bp long genome with its 3,596 protein-coding and 63 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.
RESUMEN
Pirellula staleyi Schlesner and Hirsch 1987 is the type species of the genus Pirellula of the family Planctomycetaceae. Members of this pear- or teardrop-shaped bacterium show a clearly visible pointed attachment pole and can be distinguished from other Planctomycetes by a lack of true stalks. Strains closely related to the species have been isolated from fresh and brackish water, as well as from hypersaline lakes. Here we describe the features of this organism, together with the complete genome sequence and annotation. This is the first completed genome sequence of the order Planctomyces and only the second sequence from the phylum Planctobacteria/Planctomycetes. The 6,196,199 bp long genome with its 4773 protein-coding and 49 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.
RESUMEN
Bacillus thuringiensis is an insect pathogen that is widely used as a biopesticide (E. Schnepf, N. Crickmore, J. Van Rie, D. Lereclus, J. Baum, J. Feitelson, D. R. Zeigler, and D. H. Dean, Microbiol. Mol. Biol. Rev. 62:775-806, 1998). Here we report the finished, annotated genome sequence of B. thuringiensis Al Hakam, which was collected in Iraq by the United Nations Special Commission (L. Radnedge, P. Agron, K. Hill, P. Jackson, L. Ticknor, P. Keim, and G. Andersen, Appl. Environ. Microbiol. 69:2755-2764, 2003).
Asunto(s)
Bacillus thuringiensis/genética , Genoma Bacteriano , Secuencia de Bases , Datos de Secuencia Molecular , Análisis de Secuencia de ADNRESUMEN
Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis are closely related gram-positive, spore-forming bacteria of the B. cereus sensu lato group. While independently derived strains of B. anthracis reveal conspicuous sequence homogeneity, environmental isolates of B. cereus and B. thuringiensis exhibit extensive genetic diversity. Here we report the sequencing and comparative analysis of the genomes of two members of the B. cereus group, B. thuringiensis 97-27 subsp. konkukian serotype H34, isolated from a necrotic human wound, and B. cereus E33L, which was isolated from a swab of a zebra carcass in Namibia. These two strains, when analyzed by amplified fragment length polymorphism within a collection of over 300 of B. cereus, B. thuringiensis, and B. anthracis isolates, appear closely related to B. anthracis. The B. cereus E33L isolate appears to be the nearest relative to B. anthracis identified thus far. Whole-genome sequencing of B. thuringiensis 97-27and B. cereus E33L was undertaken to identify shared and unique genes among these isolates in comparison to the genomes of pathogenic strains B. anthracis Ames and B. cereus G9241 and nonpathogenic strains B. cereus ATCC 10987 and B. cereus ATCC 14579. Comparison of these genomes revealed differences in terms of virulence, metabolic competence, structural components, and regulatory mechanisms.
Asunto(s)
Bacillus anthracis/genética , Bacillus cereus/genética , Bacillus thuringiensis/genética , Genoma Bacteriano , Análisis de Secuencia , Aminoácidos/metabolismo , Animales , Bacillus cereus/patogenicidad , Bacillus cereus/fisiología , Cápsulas Bacterianas/biosíntesis , Cápsulas Bacterianas/genética , Metabolismo de los Hidratos de Carbono , Evolución Molecular , Humanos , Esporas Bacterianas/crecimiento & desarrollo , Virulencia/genéticaRESUMEN
The reported human genome sequence includes about 400 gaps of unknown sequence that were not found in the bacterial artificial chromosome (BAC) and cosmid libraries used for sequencing of the genome. These missing sequences correspond to approximately 1% of euchromatic regions of the human genome. Gap filling is a laborious process because it relies on analysis of random clones of numerous genomic BAC or cosmid libraries. In this work we demonstrate that closing the gaps can be accelerated by a selective recombinational capture of missing chromosomal segments in yeast. The use of both methodologies allowed us to close the four remaining gaps on the human chromosome 19. Analysis of the gap sequences revealed that they contain several abnormalities that could result in instability of the sequences in microbe hosts, including large blocks of micro- and minisatellites and a high density of Alu repeats. Sequencing of the gap regions, in both BAC and YAC forms, allowed us to generate a complete sequence of four genes, including the neuronal cell signaling gene SCK1/SLI. The SCK1/SLI gene contains a record number of minisatellites, most of which are polymorphic and transmitted through meiosis following a Mendelian inheritance. In conclusion, the use of the alternative recombinational cloning system in yeast may greatly accelerate work on closing the remaining gaps in the human genome (as well as in other complex genomes) to achieve the goal of annotation of all human genes.
Asunto(s)
Elementos Alu/genética , Mapeo Cromosómico/métodos , Cromosomas Humanos Par 19/genética , Clonación Molecular/métodos , Genes/genética , Animales , Cricetinae , Eucromatina/genética , Genoma Humano , Proyecto Genoma Humano , Humanos , Células Híbridas , Datos de Secuencia Molecular , Análisis de Secuencia de ADN/métodosRESUMEN
We generated draft genome sequences for two cold-adapted Archaea, Methanogenium frigidum and Methanococcoides burtonii, to identify genotypic characteristics that distinguish them from Archaea with a higher optimal growth temperature (OGT). Comparative genomics revealed trends in amino acid and tRNA composition, and structural features of proteins. Proteins from the cold-adapted Archaea are characterized by a higher content of noncharged polar amino acids, particularly Gln and Thr and a lower content of hydrophobic amino acids, particularly Leu. Sequence data from nine methanogen genomes (OGT 15 degrees -98 degrees C) were used to generate 1111 modeled protein structures. Analysis of the models from the cold-adapted Archaea showed a strong tendency in the solvent-accessible area for more Gln, Thr, and hydrophobic residues and fewer charged residues. A cold shock domain (CSD) protein (CspA homolog) was identified in M. frigidum, two hypothetical proteins with CSD-folds in M. burtonii, and a unique winged helix DNA-binding domain protein in M. burtonii. This suggests that these types of nucleic acid binding proteins have a critical role in cold-adapted Archaea. Structural analysis of tRNA sequences from the Archaea indicated that GC content is the major factor influencing tRNA stability in hyperthermophiles, but not in the psychrophiles, mesophiles or moderate thermophiles. Below an OGT of 60 degrees C, the GC content in tRNA was largely unchanged, indicating that any requirement for flexibility of tRNA in psychrophiles is mediated by other means. This is the first time that comparisons have been performed with genome data from Archaea spanning the growth temperature extremes from psychrophiles to hyperthermophiles.
Asunto(s)
Adaptación Fisiológica/genética , Frío , Genoma Arqueal , Methanomicrobiaceae/genética , Methanosarcinaceae/genética , Secuencia de Aminoácidos , Proteínas Arqueales/genética , Proteínas Bacterianas/genética , Composición de Base , Proteínas de Unión al ADN/genética , Genes Arqueales/genética , Modelos Moleculares , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , ARN de Transferencia/química , ARN de Transferencia/genética , Proteínas de Unión al ARN/genética , Homología de Secuencia de AminoácidoRESUMEN
Diatoms are unicellular algae with plastids acquired by secondary endosymbiosis. They are responsible for approximately 20% of global carbon fixation. We report the 34 million-base pair draft nuclear genome of the marine diatom Thalassiosira pseudonana and its 129 thousand-base pair plastid and 44 thousand-base pair mitochondrial genomes. Sequence and optical restriction mapping revealed 24 diploid nuclear chromosomes. We identified novel genes for silicic acid transport and formation of silica-based cell walls, high-affinity iron uptake, biosynthetic enzymes for several types of polyunsaturated fatty acids, use of a range of nitrogenous compounds, and a complete urea cycle, all attributes that allow diatoms to prosper in aquatic environments.