Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “full genomic sequence”

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 55 records · Page 3Linked to original sources

Identification of a new HIV-2 subtype based on phylogenetic analysis of full-length genomic sequence.

Human immunodeficiency virus type 2 (HIV-2) and simian immunodeficiency virus from sooty mangabey (SIV(SM) form one of the six primate lentivirus lineages. The close phylogenetic relationship and geographic coincidence indicate that HIV-2 originated from cross-species transmission of SIV(SM) to humans. HIV-2 exhibits considerable genetic diversity, with subtypes A-F identified. Previously, we reported the partial gag and env sequences of an unusual HIV-2 isolate, Abt96. Abt96 was collected in Ivory Coast from an asymptomatic blood donor. Here we describe the near full-length genomic sequence of Abt96. The genome was assembled from overlapping PCR fragments amplified from viral RNA isolated from plasma. Phylogenetic analysis of sequences derived from segments of the Abt96 genome demonstrate that the Abt96 isolate branches independently of all other characterized HIV-2 isolates. On the basis of the phylogenetic data being presented, we propose that Abt96 is a new HIV-2 subtype and designate it subtype G.

Animals↗

Reevaluation of a North India isolate of hepatitis E virus based on the full-length genomic sequence obtained following long RT-PCR.

The genomic cloning and sequence of hepatitis E virus (HEV) from an epidemic in North India is reported. We describe here a simple method wherein the viral RNA was reverse transcribed and then amplified in a single step using an extra long polymerase chain reaction procedure. The full genome nucleotide sequence of this HEV isolate (called Yam-67) was made up of 7191 nucleotides, excepting the poly(A) tail and had three open reading frames: ORF1 coding for 1693 amino acids (aa), ORF2 coding for 659 aa and ORF3 coding for 122 aa. This North Indian isolate of HEV showed close sequence homology to other HEV isolates from India and Asia, but was distant from the Chinese genotype 4, Japanese, Mexican and US isolates. There is no indication from sequence analysis that this may be an atypical strain of HEV, as reported earlier.

Genome, Viral↗

Genome sequence, full-length infectious cDNA clone, and mapping of viral double-stranded RNA accumulation determinant of hypovirus CHV1-EP721.

Cryphonectria parasitica strain EP721 is infected with a strain of hypovirus CHV1, CHV1-EP721, and exhibits typical hypovirulence-associated traits such as reduced pigmentation and reduced asexual sporulation. However, the accumulation of the viral double-stranded RNA (dsRNA) in this hypovirus-infected C. parasitica strain is atypically low. We now report the complete nucleotide sequence and construction of a full-length infectious cDNA clone for hypovirus CHV1-EP721. The genome sequence of CHV1-EP721 was determined to be 12,724 bp in length and to share extensive homology with two other hypovirus strains, CHV1-Euro7 and CHV1-EP713, with an average of 99% and 90% identities at the nucleotide level and 99% and 92% identities at the amino acid level, respectively. CHV1-EP721 was successfully introduced into virus-free fungal host strain EP721(-v) by transfection with transcripts derived from a full-length viral cDNA. The transfected strain had a phenotype indistinguishable from that of EP721, and the accumulation of CHV1-EP721 dsRNA in the transfectant was lower than those transfected by CHV1-Euro7 and CHV1-EP713 transcripts. Through the construction of chimeric viruses by domain swapping using infectious cDNA clones of CHV1-EP721, CHV1-EP713, and CHV1-Euro7 hypoviruses, the determinant for the low level of viral dsRNA accumulation in CHV1-EP721 was mapped to the second of two CHV1-EP721 open reading frames (ORFs), ORF B. Further refined swapping of domains within ORF B identified a 2.5-kb coding region between p48 and the polymerase domain of CHV1-EP721 as being responsible for the low viral dsRNA accumulation. Evidence is also provided that low rates of hypovirus transmission through conidial spores correlates with low viral dsRNA accumulation.

Ascomycota↗

HIV type 1 strains common in Europe, Africa, and Asia cocirculate in Yemen.

To determine the HIV-1 genetic diversity in Yemen, 19 strains collected from men and women were sequenced in pol and six of those were full genome sequenced; all were phylogenetically analyzed. Using the pol sequence data, nine (47.3%) were subtype B, six (31.6%) subtype C, two (10.5%) subtype D, one strain (5.3%) subtype A, and another (5.3%) a unique recombinant form (URF). Concordant phylogenies were also obtained for the six strains full genome sequenced. Most of the strains were from the capitol, Sana'a (n=16). Five of the C strains clustered with African Cs, and one clustered with the Indian C strains. Of the two subtype D strains, one clustered with Ugandan strains and one with Cameroon. The subtype A strain was similar to a Cameroon variant of subtype A and the URF strain was a recombinant between CRF11, CRF13, and subtype B. The HIV epidemic in Yemen is extremely complex, with strains of HIV-1 that have originated in East and West Africa, Europe, and India.

Adult↗

Hepatitis B virus genotype assignment using restriction fragment length polymorphism patterns.

Hepatitis B virus (HBV) is classified into genotypes A-F, which is important for clinical and etiological investigations. To establish a simple genotyping method, 68 full-genomic sequences and 106 S gene sequences were analyzed by the molecular evolutionary method. HBV genotyping with the S gene sequence is consistent with genetic analysis using the full-genomic sequence. After alignment of the S sequences, genotype specific regions are identified and digested by the restriction enzymes, HphI, NciI, AlwI, EarI, and NlaIV. This HBV genotyping system using restriction fragment length polymorphism (RFLP) was confirmed to be correct when the PCR products of the S gene in 23 isolates collected from various countries were digested with this method. A restriction site for EarI in genotype B was absent in spite of its presence in all the other genotypes and genotype C has no restriction site for AlwI. Only genotype E is digested with NciI, while only genotype F has a restriction site for HphI. Genotype A can be distinguished by a single restriction enzyme site for NlaIV, while genotype D digestion with this enzyme results in two products that migrates at 265 and 186 bp. This simple and accurate HBV genotyping system using RFLP is considered to be useful for research on HBV.

Base Sequence↗

Characteristics of hepatitis B virus in Ghana: full length genome sequences indicate the endemicity of genotype E in West Africa.

Hepatitis B virus (HBV) genotypes from A to H have distinct geographical distributions and have been shown to affect the clinical features as well as the course of the HBV infection. HBV genotype E has been found only in Africa. However, the complete genomes of this genotype, which were isolated mainly from West Africa, were available only for a few samples. In this study, five full-length genomes and seven other small S genes of HBV strains from Ghanaian blood donors were sequenced and investigated. Following phylogenetic analysis, all of the Ghanaian HBV strains were clustered closely in genotype E. All of the 12 small S genes showed the same characteristic of subtype ayw4. The complete genomes of the five Ghanaian strains showed marked similarity with each other and with the reported genotype E strains (96.7%-99.1%). Genotype E strains showed low intra-genotypic diversity (1.8%) and carried the conserved signature pattern in pre-S1 as well as in the full genome sequence. Of note, the finding of the G145R escape mutant in an unvaccinated Ghanaian blood donor might raise concern as to the ongoing nation-wide hepatitis B vaccination program in Ghana.

Amino Acid Sequence↗

Completion of the full-length genome sequence of Menangle virus: characterisation of the polymerase gene and genomic 5' trailer region.

Menangle virus (MenV), isolated in 1997 from stillborn piglets during an outbreak of reproductive disease at a large commercial piggery, is the only new paramyxovirus to be identified in Australia since Hendra virus in 1994. Following partial characterisation of the MenV genome, we previously showed that MenV is a novel member of the genus Rubulavirus. Here we report the characterisation of the large (L) polymerase gene and the adjacent 5' trailer region of MenV, which completes the full-length genome sequence of this novel paramyxovirus (15,516 nucleotides), and thereby confirm its taxonomic position within the family Paramyxoviridae.

Amino Acid Sequence↗

Near-full-length genome sequencing of divergent African HIV type 1 subtype F viruses leads to the identification of a new HIV type 1 subtype designated K.

We recently reported a high divergence among African subtype F strains. Three well-separated groups (F1, F2, and F3) have been shown based on the phylogenetic analysis of the p24 gag and envelope sequences with genetic distances similar to those observed for known subtypes. In this study, we characterized the near-full-length genomes of two strains from epidemiological unlinked individual belonging to each of the subgroups: F1 (96FR-MP411), F2 (95CM-MP255 and 95CM-MP257), and F3 (96CM-MP535 and 97ZR-EQTB11). Phylogenetic analysis of the near-full-length sequences and for each of the genes separately showed the same three groups, supported by high bootstrap values. Diversity plotting, BLAST subtyping, and bootstrap plotting confirmed that the divergent F strains correspond to nonrecombinant viruses. The divergence between F1 and F2 is consistently lower than that seen in any other intersubtype comparison, with the exception of subtypes B and D. Based on all the different analyses, we propose to divide subtype F into two subclades, with F1 gathering the known subtype F strains from Brazil and Finland, and our African strain (96FR-MP411), and F2 containing the 95CM-MP255 and 95CM-MP257 strains from Cameroon. The F3 strains, 97ZR-EQTB11 from the Democratic Republic of Congo and 96CM-MP535 from Cameroon, meet the criteria of a new subtype designated as K. The equidistance of subtype K to the other subtypes of HIV-1 suggests that this subtype existed as long as the others, the lower distance between B and D, and between F1 and F2 suggest a more recent subdivision for these latter strains.

Africa↗

Diversity of mosaic structures and common ancestry of human immunodeficiency virus type 1 BF intersubtype recombinant viruses from Argentina revealed by analysis of near full-length genome sequences.

The findings that BF intersubtype recombinant human immunodeficiency type 1 viruses (HIV-1) with coincident breakpoints in pol are circulating widely in Argentina and that non-recombinant F subtype viruses have failed to be detected in this country were reported recently. To analyse the mosaic structures of these viruses and to determine their phylogenetic relationship, near full-length proviral genomes of eight of these recombinant viruses were amplified by PCR and sequenced. Intersubtype breakpoints were analysed by bootscanning and examining the signature nucleotides. Phylogenetic relationships were determined with neighbour-joining trees. Five viruses, each with predominantly subtype F genomes, exhibited mosaic structures that were highly similar. Two intersubtype breakpoints were shared by all viruses and seven by the majority. Of the consensus breakpoints, all nine were present in two viruses, which exhibited identical recombinant structures, and four to eight breakpoints were present in the remaining viruses. Phylogenetic analysis of partial sequences supported both a common ancestry, at least in part of their genomes, for all recombinant viruses and the phylogenetic relationship of F subtype segments with F subtype viruses from Brazil. A common ancestry of the recombinants was supported also by the presence of shared signature amino acids and nucleotides, either unreported or highly unusual in F and B subtype viruses. These results indicate that HIV-1 BF recombinant viruses with diverse mosaic structures, including a circulating recombinant form (which are widespread in Argentina) derive from a common recombinant ancestor and that F subtype segments of these recombinants are related phylogenetically to the F subtype viruses from Brazil.

Argentina↗

Postgenomic taxonomy of human ureaplasmas -- a case study based on multiple gene sequences.

In 2000, the full genome sequence of Ureaplasma parvum (previously known as Ureaplasma urealyticum) serovar 3 was released. In 2002, after prolonged debate, it was agreed that the former U. urealyticum should be divided into two species -- U. parvum and U. urealyticum. To provide additional support for this decision and improve our understanding of the relationship between these two species, the authors studied four 'core' genes or gene clusters in ATCC reference strains of all 14 serovars of U. parvum and U. urealyticum. These 'core' regions were the rRNA gene clusters, the EF-Tu genes (tuf), urease gene clusters and multiple-banded antigen genes (mba). The known U. parvum genome sequences (GenBank accession no. NC_002162) were used as reference. DNA insertions and deletions (indels) were found in all of the gene regions studied, except tuf, but they were found only between, not within, the two species. An incidental finding was that there was inter-copy heterogeneity for rRNA gene cluster sequences. Sequence analysis (sequence heterogeneity and especially indels) of all four selected targets consistently supported the separation of human ureaplasmas into two species. Except for multiple-banded antigen, there was less heterogeneity in amino acid sequences of proteins, between species, than in the nucleic acid sequences of the corresponding genes. The degrees of heterogeneity at the 5' end of the species-specific regions of multiple-banded antigen were almost identical for both amino acid and nucleotide sequences. Analysis of the authors' results provided an interesting case study to help resolve some common problems in the use of sequence data to infer phylogenetic relationships and support taxonomic changes. It is recommended that, to avoid confusion, the new nomenclature be used for human ureaplasmas in future publications.

Bacterial Proteins↗

Characterisation of near-full length genome sequences of three South African human immunodeficiency virus type 1 subtype C isolates.

As subtype C is the most prevalent circulating human immunodeficiency virus type 1 (HIV-1) subtype internationally as well as locally in South Africa, more information on the biological nature and molecular characteristics of these viruses is required. Proviral DNA was isolated from primary cultures of three South African R5 isolates and the near-full length genome amplified by PCR. The resultant PCR product was cloned into the pCR-XL-TOPO vector and a representative clone from each isolate sequenced by primer walking. Phylogenetic analysis showed all three clones clustered within subtype C with a bootstrap value of 100%, and no recombination with other subtypes was identified by distance scan and bootscan analysis. Analysis of the potential coding regions revealed premature truncations of the second rev exon but no other potential structural distortions nor frameshift mutations in the open reading frames. All the clones contained three potential NF-kappaB binding sites, a feature unique to subtype C viruses. The tips of the V3 loops contained the GPGQ sequence motif characteristic of CCR5-utilising subtype C strains, as well as relatively low overall net positive charge characteristic of non-syncytium-inducing isolates. This information contributes to our overall knowledge of circulating strains in South Africa and to the making of effective vaccines and chemotherapeutic agents.

Amino Acid Sequence↗

Further evidence of the absence of measles virus genome sequence in full thickness intestinal specimens from patients with Crohn's disease.

Specimens of macroscopically inflamed and normal intestine along with mesenteric lymph nodes were obtained at resection from patients with Crohn's disease. The samples were systematically examined by RT-PCR-nested PCR targeting N, M and H gene regions of the measles virus genome. None of the samples examined gave any evidence of the persistence of measles virus in the intestine of Crohn's disease patients. The study supports previous findings produced by this laboratory and others using highly sensitive measles virus specific PCR diagnostic technology.

Adult↗

Development and application of a high-throughput HIV type 1 genotyping assay to identify CRF02_AG in West/West Central Africa.

In West/West Central Africa, CRF02_AG is the most prevalent HIV-1 strain and circulates in the milieu of rare subtypes, circulating recombinant forms (CRFs), and unique recombinant forms (URFs). The molecular complexity of HIV-1 epidemics in this region and the need to extensively sample large populations, such as in the case of vaccine trials, pose seemingly conflicting requirements between full-genome sequencing and high-throughput low-resolution assays. Here we describe the development and evaluation of a multiregion hybridization assay (MHAcrf02) for the efficient genotyping of CRF02_AG in West/West Central Africa. Subtype A, G, and CRF02_AG-specific fluorescent probes were designed flanking five recombination breakpoints in CRF02_AG and were used in real-time PCRs. A panel representing West/West Central African HIV-1 genetic diversity was evaluated by MHAcrf02. The sample set, previously characterized by full-genome sequencing, included CRF02_AG and CRF02_AG-containing recombinants (n = 28), other subtypes, CRFs, and URFs (n = 34). DNA from peripheral blood mononuclear cells, cocultures, and plasmids was used as template. When the patterns of probe reactivity were evaluated. CRF02_AG was identified with a 100% specificity and sensitivity. In conclusion, MHAcrf02 will permit more efficient characterization of HIV-1 in West/West Central Africa, where CRF02_AG is an important strain. Together with other regional genotyping assays MHAcrf02 will contribute to the development of a global picture of HIV-1 diversity and geographic distribution, providing a strong foundation for intervention, including vaccine development.

Africa, Central↗

Detection of HIV-1 subtypes, recombinants, and dual infections in east Africa by a multi-region hybridization assay.

OBJECTIVE: To enable more rapid and efficient genotyping of HIV-1 in East Africa, where subtypes A, C, and D and their recombinants are co-circulating. DESIGN: Full-genome sequencing of HIV-1 provides complete discrimination of subtypes and recombinant forms but is costly and low-throughput compared to other genotyping approaches. Here we describe the development and evaluation of a Multi-region Hybridization Assay (MHA) for the efficient determination of HIV-1 subtypes A, C, D, recombinants, and dual infections. METHODS: Five genome regions containing clustered mutations distinguishing subtypes A, C, and D were identified and used to design subtype-specific probes. DNA from primary peripheral blood mononuclear cells was used as template for real-time PCR using the fluorescent, subtype-specific probes. RESULTS: A panel of 45 clinical samples from Uganda, Kenya, and Tanzania, previously characterized by full-genome sequencing and including 26 pure subtypes and 19 recombinant strains, was evaluated by MHA. The MHA provided 90% sensitivity and 98% specificity for the three subtypes, efficiently discriminated subtypes from recombinant forms, and detected several dual infections. CONCLUSIONS: Accurate and efficient genotyping of HIV-1 strains in vaccine trial populations in East Africa, ascertainment of dual infections, and elucidation of the genesis of recombinant forms in individuals can be facilitated by the application of MHA.

Africa, Eastern↗

Comparison of the full-length genome sequence of avian metapneumovirus subtype C with other paramyxoviruses.

We determined the nucleotide (nt) sequence of the small hydrophobic (SH), attachment glycoprotein (G), and RNA polymerase (L) genes, plus the leader and trailer regions of the Colorado strain of Avian metapneumovirus subtype C (aMPV/C) in order to complete the genome sequencing. The complete genome comprised of 13,134 nucleotides, with a 40 nt leader at its 3' end and a 45 nt trailer at its 5' end. The aMPV/C L gene was the largest with 6173 nt and consisting of a single open reading frame encoding a 2005 amino acids (aa) protein. Comparison of the aMPV/C SH, G, and L nt and predicted aa sequences with those of Human metapneumoviruses (hMPV) revealed higher nt and aa sequence identities than the sequence identities between the aMPV subtypes A, B, C, and D, supporting earlier finding that aMPV/C was closer evolutionary to hMPV than the other aMPV subtypes.

Amino Acid Sequence↗