Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Genomic sequencing”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,351 records · Page 75Linked to original sources

Recognizing exons in genomic sequence using GRAIL II.

We have described an improved neural network system for recognizing protein coding regions (exons) in human genomic DNA sequences. This coding region recognition system is part of a new version of GRAIL, GRAIL II, and represents a significant improvement over the coding recognition performance of the previous GRAIL system. GRAIL II divides the process of locating exons into four steps. It first generates an exon candidate pool consisting of all possible (translation start-donor), (acceptor-donor), and (acceptor-translation stop) pairs within all open reading frames of the test sequence. The vast majority of these exon candidates are eliminated from consideration by applying a set of heuristic rules. After reducing the size of the candidate pool, GRAIL II uses three trained neural networks to evaluate the coding potential and accuracy of the edges of starting exon, internal exon and terminal exon candidates. These networks output a set of overlapping candidates for each exon which differ by their scores and position of their edges. Multiple candidates for a given exon are grouped into a cluster based on their locations relative to candidates corresponding to other exons, and the highest scoring candidate for each cluster is used as the "best" prediction of the corresponding exon. Unlike the previous GRAIL version, GRAIL II uses variable-length windows to evaluate exon candidates and its performance is nearly independent of exon length. In addition to several strong indicators of coding potential, the system uses several other types of information including scores for splice junctions, GC composition, and the properties of the regions adjacent to an exon candidate, to aid in the discrimination process. On a large set of sequences from Genbank (3), GRAIL II located 93% of all exons regardless of size with a false positive rate of 12%. Among the true positives, 62% match the actual exons exactly (the exons edges are correct to the base), and 93% match at least one edge correctly. These statistics are further improved, especially the false positive rate and accuracy of the edges, through a process of gene model construction by the Gene Assembly Program (GAP III) (4) module of GRAIL II, which uses the scored exon candidates as input and constructs optimal gene models. The gene modeling system will be described elsewhere.

Amino Acid Sequence↗

An emerging phylogenetic core of Archaea: phylogenies of transcription and translation machineries converge following addition of new genome sequences.

BACKGROUND: The concept of a genomic core, defined as the set of genes ubiquitous in all genomes of a monophyletic group, has become crucial in comparative and evolutionary genomics. However, it is still a matter of debate whether lateral gene transfers (LGT) may affect the components of genomic cores, preventing their use to retrace species evolution. We have recently reconstructed the phylogeny of Archaea by using two large concatenated datasets of core proteins involved in translation and transcription, respectively. The resulting trees were largely congruent, showing that informational gene components of the archaeal genomic core belonging to two distinct molecular systems contain a coherent signal for archaeal phylogeny. However, some incongruence remained between the two phylogenies. This may be due either to undetected LGT and/or to a lack of sufficient phylogenetic signal in the datasets. RESULTS: We present evidence strongly favoring of the latter hypothesis. In fact, we have updated our transcription and translation datasets with five new archaeal genomes for a total of 6384 and 2928 amino acid positions, respectively, and 25 taxa. This increase in taxonomic sampling led to the nearly complete convergence of the transcription-based and translation-based trees on a single phylogenetic pattern for archaeal evolution. In fact, only a single incongruence persisted between the two phylogenies. This concerned Methanopyrus kandleri, whose placement remained strongly biased in the transcription tree due to its above average evolutionary rates, and could not be counterbalanced due to the lack of availability of closely related and/or slower-evolving relatives. CONCLUSION: To our knowledge, this is the first report of evidence that the phylogenetic signal harbored by components of the archaeal translation apparatus is confirmed by additional markers belonging to a second molecular system (i.e. transcription). This rules out the risk of circularity when inferring species evolution by small subunit ribosomal RNA and ribosomal protein sequences, since it has been suggested that concerted LGT may affect these markers. Our results strongly support the existence of a core of proteins that has evolved mainly through vertical inheritance in Archaea, and carries a bona fide phylogenetic signal that can be used to retrace the evolutionary history of this domain. The identification and analysis of additional molecular markers not affected by LGT should continue defining the emerging picture of a genuine phylogenetic core for the third domain of life.

Algorithms↗

Population-level genomic surveillance of human norovirus using wastewater-based whole-genome sequencing.

Wastewater-based surveillance has garnered increasing attention as a valuable approach for capturing community-level infection dynamics that are often difficult to detect through clinical reporting systems alone. In this study, we analyzed human norovirus genotype distributions and whole-genome-level variations in wastewater samples collected in Gwangju, Korea. These results were interpreted in conjunction with a documented foodborne outbreak to evaluate the epidemiological relevance of wastewater-based monitoring. Human norovirus concentrations were quantified using TaqMan Array Card-based RT-qPCR, and whole-genome next-generation sequencing (NGS) was performed to obtain viral read counts and reads per kilobase per million filtered reads values. Overall, strong correlations were observed between RT-qPCR-based concentrations and NGS-derived metrics. Genotype dynamics varied among wastewater treatment plants, reflecting differences in catchment size and local population characteristics. In particular, the relative abundance of GII.17[P17] increased during epidemiological week 50, temporally coinciding with a documented local foodborne outbreak. Variant analysis revealed that wastewater samples exhibited mixed nucleotide patterns, with multiple alleles coexisting at varying relative frequencies rather than fixed substitutions. Notably, some nonsynonymous variants detected in clinical samples were also observed in wastewater samples collected surrounding the outbreak period. Together, these findings demonstrate that wastewater-based whole-genome surveillance can capture both genotype-level shifts and nucleotide-level dynamics at the population scale, highlighting its potential as a complementary tool for monitoring community-level norovirus circulation and outbreak-associated genotype dynamics.IMPORTANCEWastewater-based surveillance is increasingly recognized as a promising approach for capturing community-level infection dynamics that are often missed by clinical surveillance. In this study, we applied whole-genome sequencing to wastewater samples collected in Gwangju, South Korea, to comprehensively characterize human norovirus genotype distributions and genetic variation. Distinct genotype patterns were observed across wastewater treatment plants, reflecting differences in catchment population size and local characteristics. Notably, an increase in the GII.17[P17] genotype detected in wastewater coincided with a foodborne outbreak investigated in Gwangju, demonstrating the potential of wastewater surveillance to reflect ongoing community transmission and emerging outbreak-associated genotypes. In addition, wastewater samples contained diverse and coexisting genetic variants, capturing population-level viral diversity and evolutionary dynamics that are not readily detected through clinical surveillance alone. These findings highlight the value of wastewater-based whole-genome surveillance for monitoring community-level viral circulation and support its integration as a complementary strategy to existing clinical surveillance systems.

genotype dynamics↗

Sequencing the genome of Plasmodium falciparum.

Advances in microbial genomic sequencing have the potential to revolutionize the control of infectious diseases. Recently, a consortium of researchers and funding agencies from the United States and Great Britain have embarked on a project to sequence the genome from Plasmodium falciparum, the most important cause of human malaria. The Malaria Genome Sequencing Project has reached an important milestone with the completion of the entire DNA sequence and annotation of chromosome 2, a 950 kilobase chromosome of Plasmodium falciparum. This review article will provide an overview of the malaria genome sequencing project, highlight progress in the field of microbial sequencing, and suggest new directions for future malaria research.

Journal Article↗

Multiple members of a third subfamily of P-type ATPases identified by genomic sequences and ESTs.

The Saccharomyces cerevisiae genome contains five P-type ATPases divergent from both of the well-known subfamilies of these membrane ion transporters. This newly recognized third subfamily can be further divided into four classes of genes with nearly equal relatedness to each other. Genes of this new subfamily are also present and expressed in multicellular organisms such as Caenorhabditis elegans and mammals; some, but not all, can be assigned to the classes identified in yeast. Different classes of genes and different genes within a class are expressed differentially in tissues of the mouse. The recently cloned gene for the mammalian aminophospholipid translocase belongs to this new subfamily, suggesting that other subfamily members may transport other lipids or lipid-like molecules from one leaflet of the membrane bilayer to the other.

Adenosine Triphosphatases↗

Determination and comparative analysis of the small RNA genomic sequences of California encephalitis, Jamestown Canyon, Jerry Slough, Melao, Keystone and Trivittatus viruses (Bunyaviridae, genus Bunyavirus, California serogroup).

The nucleotide sequences of the small (S) genomic RNAs of six California (CAL) serogroup bunyaviruses (Bunyaviridae: genus Bunyavirus) were determined. The S RNAs of two California encephalitis virus strains, two Jamestown Canyon virus strains, Jerry Slough virus, Melao virus, Keystone virus and Trivittatus virus contained the overlapping nucleocapsid (N) and non-structural (NSs) protein open reading frames (ORFs) as described previously for the S RNAs of other CAL serogroup viruses. All N protein ORFs were 708 nucleotides in length and encoded a putative 235 amino acid gene product. The NSs ORFs were found to be of two lengths, 279 and 294 nucleotides, which potentially encode 92 and 97 amino acid proteins, respectively. The complementary termini and a purine-rich sequence in the 3' non-coding region (genome-complementary sense) were highly conserved amongst CAL serogroup bunyavirus S RNAs. Phylogenetic analyses of N ORF sequences indicate that the CAL serogroup bunyaviruses can be divided into three monophyletic lineages corresponding to three of the complexes previously derived by serological classification. The truncated version of the NSs protein, which is found in five CAL serogroup bunyaviruses, appears to have arisen twice during virus evolution.

Amino Acid Sequence↗

Integrated exome and mitochondrial genome sequencing reveals the genetic landscape of primary mitochondrial diseases: findings from a large Tunisian cohort.

Primary mitochondrial diseases are a heterogeneous group of neurometabolic disorders recognized as the most common metabolic genetic diseases. They manifest at any age, affecting any tissue or organ, especially those with high energy demands, and are caused by pathogenic variants in both mitochondrial and nuclear genomes. Here, we aimed to describe the genetic spectrum of a Tunisian pediatric cohort with suspected mitochondrial diseases. We recruited 47 unrelated families who underwent exome sequencing as a first-tier test followed by whole mitochondrial genome sequencing for unsolved cases. Dedicated bioinformatic pipelines and prediction tools were used to determine the potential disease-causing variants. Sanger sequencing confirmed the presence and segregation within parents. For the newly identified variants, structural modeling was conducted to study the impact of these variants on protein structure and motions. Dual genome sequencing yielded a molecular diagnosis in 33/47 families (70%) and 18/47 (38%) showed disease-causing variants in genes encoding mitochondrial proteins. Among them, four families disclosed novel variants in FASTKD2, SERAC1 and GATB, which were supported by in-depth in silico and structural analyses demonstrating their deleterious effect. The remaining families (32%, 15/47) disclosed other metabolic and neurological disorders. An exome-first strategy delivers a high diagnostic yield in Tunisia, where consanguinity remains high and simultaneously captures mitochondrial and non-mitochondrial etiologies. Mitochondrial sequencing remains indispensable in the case of an inconclusive exome. Thus, our data expand the clinical and genetic spectrum of primary mitochondrial diseases in Tunisia, an underrepresented and admixed population.

Humans↗

The genomic sequence and comparative analysis of the rat major histocompatibility complex.

We have determined the sequence of a 4-Mb interval on rat chromosome 20p12 that encompasses the rat major histocompatibility complex (MHC). This is the first report of a finished sequence for a segment of the rat genome and constitutes one of the largest contiguous sequences thus far for rodent genomes in general. The rat MHC is, next to the human MHC, the second mammalian MHC sequenced to completion. Our analysis has resulted in the identification of at least 220 genes located within the sequenced interval. Although gene content and order are well conserved in the class II and class III gene intervals as well as the framework gene regions, profound rat-specific features were encountered within the class I gene regions, in comparison to human and mouse. Class I region-associated differences were found both at the structural level, the number, and organization of class I genes and gene families, and, in a more global context, in the way that evolution worked to shape the present-day rat MHC.

Animals↗

A genomic sequence of the Schizosaccharomyces pombe 16 kDa vacuolar H(+)-ATPase.

We have isolated the gene encoding the 16 kDa vacuolar H(+)-ATPase from Schizosaccharomyces pombe. On the basis of RNA splicing signals and amino acid sequence homology with other 16 kDa H(+)-ATPases, the genomic DNA sequence indicated the 16 kDa protein is encoded by five exons. The C-terminal 50 amino acids has more than 90% homology with vacuolar H(+)-ATPases of mammalian cells.

Amino Acid Sequence↗

Life in hot carbon monoxide: the complete genome sequence of Carboxydothermus hydrogenoformans Z-2901.

We report here the sequencing and analysis of the genome of the thermophilic bacterium Carboxydothermus hydrogenoformans Z-2901. This species is a model for studies of hydrogenogens, which are diverse bacteria and archaea that grow anaerobically utilizing carbon monoxide (CO) as their sole carbon source and water as an electron acceptor, producing carbon dioxide and hydrogen as waste products. Organisms that make use of CO do so through carbon monoxide dehydrogenase complexes. Remarkably, analysis of the genome of C. hydrogenoformans reveals the presence of at least five highly differentiated anaerobic carbon monoxide dehydrogenase complexes, which may in part explain how this species is able to grow so much more rapidly on CO than many other species. Analysis of the genome also has provided many general insights into the metabolism of this organism which should make it easier to use it as a source of biologically produced hydrogen gas. One surprising finding is the presence of many genes previously found only in sporulating species in the Firmicutes Phylum. Although this species is also a Firmicutes, it was not known to sporulate previously. Here we show that it does sporulate and because it is missing many of the genes involved in sporulation in other species, this organism may serve as a "minimal" model for sporulation studies. In addition, using phylogenetic profile analysis, we have identified many uncharacterized gene families found in all known sporulating Firmicutes, but not in any non-sporulating bacteria, including a sigma factor not known to be involved in sporulation previously.

Base Sequence↗

Laminin A chain: expression during Drosophila development and genomic sequence.

A Drosophila laminin A chain gene was characterized as a 14 kb genomic nucleotide sequence which encodes an open reading frame of 3712 amino acids in 15 exons. Overall, this A chain is similar to its vertebrate counterparts, especially in its N- and C-terminal globular domains, but the sequence that forms the laminin A short arm is quite different and larger. Laminin messages appear in newly formed mesoderm and are later prominently expressed in hemocytes, which also synthesize basement membrane collagen IV. The composition of Drosophila basement membranes changes with development. A novel method of tandemly fused RNA probes showed that developmental increases of laminin mRNAs were primarily associated with periods of morphogenesis, and preceded those of collagen IV, a protein strongly expressed during growth. The ratio of A:B1:B2 mRNAs varied little during embryogenesis, with less mRNA for A than B chains. Staining of embryos with antibodies confirmed and extended the information provided by in situ hybridization. Homologs of the G-subdomains of this A chain, which occur in interacting regions of agrin, perlecan, laminin and sex steroid binding protein, may be involved in protein associations.

Amino Acid Sequence↗

Presence of complete murine viral genome sequences in patient-derived xenografts.

Patient-derived xenografts are crucial for drug development but their use is challenged by issues such as murine viral infection. We evaluate the scope of viral infection and its impact on patient-derived xenografts by taking an unbiased data-driven approach to analyze unmapped RNA-Seq reads from 184 experiments. We find and experimentally validate the extensive presence of murine viral sequence reads covering entire viral genomes in patient-derived xenografts. The existence of viral sequences inside tumor cells is further confirmed by single cell sequencing data. Extensive chimeric reads containing both viral and human sequences are also observed. Furthermore, we find significantly changed expression levels of many cancer-, immune-, and drug metabolism-related genes in samples with high virus load. Our analyses indicate a need to carefully evaluate the impact of viral infection on patient-derived xenografts for drug development. They also point to a need for attention to quality control of patient-derived xenograft experiments.

Animals↗

The genomic sequence of Wisteria vein mosaic virus and its similarities with other potyviruses.

The complete nucleotide sequence of a Beijing isolate of Wisteria vein mosaic virus was determined to be 9695 nucleotides in length excluding the poly(A) tail. Sequence analysis predicted a single large open reading frame of 9279 nucleotides potentially encodes a polyprotein of 3092 amino acids. Phylogenetic analysis based on the genomic and deduced amino acid sequences support the current status of Wisteria vein mosaic virus (WVMV) as a distinct virus of the genus Potyvirus and a member of the Bean common mosaic virus (BCMV) subgroup. Sequence comparisons of WVMV and other members of the BCMV subgroup showed that WVMV is most closely related to both soybean mosaic virus and watermelon mosaic virus.

Amino Acid Sequence↗

Genome sequence and organization of a nucleopolyhedrovirus isolated from the smaller tea tortrix, Adoxophyes honmai.

Adoxophyes honmai nucleopolyhedrovirus (AdhoNPV) has a distinctive pathology in A. honmai larvae, killing the host more slowly than other NPVs. To further understand the pathology of AdhoNPV, its genome was completely sequenced and compared with those of other baculoviruses. The AdhoNPV genome is 113,220 bp, with a G + C content of 35.6%. It contains 125 putative open reading frames (ORFs), of which 8 are unique to AdhoNPV, and 4 homologous regions. The other 117 ORFs display similarity to previously characterized baculovirus genes involved in early and late gene expression, DNA replication, and structural and auxiliary functions. The phylogenetic position of AdhoNPV, in relation to 15 other baculoviruses whose genomes have been completely sequenced, was assessed by three different analyses: gene sequence, gene order, and gene content. Although gene content analysis failed to support the group II NPVs, phylogenetic trees based on gene sequence and gene order showed AdhoNPV to be closely related to the group II NPVs.

Amino Acid Sequence↗

Genome sequence of Aeromonas hydrophila ATCC 7966T: jack of all trades.

The complete genome of Aeromonas hydrophila ATCC 7966(T) was sequenced. Aeromonas, a ubiquitous waterborne bacterium, has been placed by the Environmental Protection Agency on the Contaminant Candidate List because of its potential to cause human disease. The 4.7-Mb genome of this emerging pathogen shows a physiologically adroit organism with broad metabolic capabilities and considerable virulence potential. A large array of virulence genes, including some identified in clinical isolates of Aeromonas spp. or Vibrio spp., may confer upon this organism the ability to infect a wide range of hosts. However, two recognized virulence markers, a type III secretion system and a lateral flagellum, that are reported in other A. hydrophila strains are not identified in the sequenced isolate, ATCC 7966(T). Given the ubiquity and free-living lifestyle of this organism, there is relatively little evidence of fluidity in terms of mobile elements in the genome of this particular strain. Notable aspects of the metabolic repertoire of A. hydrophila include dissimilatory sulfate reduction and resistance mechanisms (such as thiopurine reductase, arsenate reductase, and phosphonate degradation enzymes) against toxic compounds encountered in polluted waters. These enzymes may have bioremediative as well as industrial potential. Thus, the A. hydrophila genome sequence provides valuable insights into its ability to flourish in both aquatic and host environments.

Aeromonas hydrophila↗

Genomic sequence and embryonic expression of the zebrafish homeobox gene hox-3.4.

We have analyzed the genomic DNA sequence and embryonic expression pattern of the zebrafish hox-3.4 gene. Two exons, encoding a protein with a total size of 232 amino acids, were identified within a 3.5 kbp genomic region. Besides the homeodomain, which is identical to that of the human HOX3D and mouse Hox-3.4 genes, the first 58 residues of the N-terminal domain in the predicted Hox-3.4 protein share 48% sequence identity with the gene product of the human cognate. Some of the N-terminal sequence elements are also conserved relative to the two other members of the Hox-1.3/Hox-2.1/Hox-3.4 paralogy group. In addition, the paralogous genes share a significant degree of sequence identity in non-coding regions. This conservation is particularly evident in the promoter regions of the cognates hox-3.4, Hox-3.4, and HOX3D, where a 180 bp TATA-box-containing element with a 60% identity is located. This is in agreement with the previous finding that the HOX3D promoter region contains response elements for other Hox proteins and retinoids. Also with respect to embryonic expression, the zebrafish hox-3.4 gene is very similar to its mammalian counterparts. Within the central nervous system of 16, 24, and 48 h embryos, hox-3.4 transcripts were detected throughout most of the spinal cord from a boundary at the posterior end of the hindbrain. In 16 h embryos the hox-3.4 gene is also active within a restricted region of the tailbud.

Amino Acid Sequence↗