scholarly journals Sequence analysis of the equid herpesvirus 2 chemokine receptor homologues E1, ORF74 and E6 demonstrates high sequence divergence between field isolates

2007 ◽  
Vol 88 (9) ◽  
pp. 2450-2462 ◽  
Author(s):  
Emma L. Sharp ◽  
Helen E. Farrell ◽  
Kerstin Borchers ◽  
Edward C. Holmes ◽  
Nicholas J. Davis-Poynter
Keyword(s):  
Chemokine Receptors ◽  
Sequence Data ◽  
Sequence Divergence ◽  
Gene Families ◽  
Open Reading Frames ◽  
Amino Acid Difference ◽  
Transmembrane Receptors ◽  
Equid Herpesvirus ◽  
High Sequence Divergence ◽  
Reading Frames

Equid herpesvirus 2 (EHV-2), in common with other members of the subfamily Gammaherpesvirinae, encodes homologues of cellular seven-transmembrane receptors (7TMR), namely open reading frames (ORFs) E1, 74 and E6, which each show some similarity to cellular chemokine receptors. Whereas ORF74 and E6 are members of gammaherpesvirus-conserved 7TMR gene families, E1 is currently unique to EHV-2. To investigate their genetic variability, EHV-2 7TMRs from a panel of equine gammaherpesvirus isolates were sequenced. A region of gB was sequenced to provide comparative sequence data. Phylogenetic analysis revealed six ‘genogroups’ for E1 and four for ORF74, which exhibited approximately 10–38 and 11–27 % amino acid difference between groups, respectively. In contrast, E6 was highly conserved, with two genogroups identified. The greatest variation was observed within the N-terminal domains and other extracellular regions. Nevertheless, analysis of the number of non-synonymous (d N) and synonymous (d S) substitutions per site generally supported the hypothesis that the 7TMRs are under negative selective pressure to retain functionally important residues, although some site-specific positive selection (d N>d S) was also observed. Collectively, these data are consistent with transmembrane and cytoplasmic domains being less tolerant of mutations with adverse effects upon function. Finally, there was no evidence for genetic linkage between the different gB, E1, ORF74 and E6 genotypes, suggesting frequent intergenic recombination between different EHV-2 strains.

scholarly journals Gene Cassette PCR: Sequence-Independent Recovery of Entire Genes from Environmental DNA

2001 ◽  
Vol 67 (11) ◽  
pp. 5240-5246 ◽  
Author(s):  
H. W. Stokes ◽  
Andrew J. Holmes ◽  
Blair S. Nield ◽  
Marita P. Holley ◽  
K. M. Helena Nevalainen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Sequence Data ◽  
Environmental Dna ◽  
Gene Families ◽  
Soil Samples ◽  
Open Reading Frames ◽  
Sequence Information ◽  
Gene Cassettes ◽  
Conserved Sequence ◽  
Reading Frames

ABSTRACT The vast majority of bacteria in the environment have yet to be cultured. Consequently, a major proportion of both genetic diversity within known gene families and an unknown number of novel gene families reside in these uncultured organisms. Isolation of these genes is limited by lack of sequence information. Where such sequence data exist, PCR directed at conserved sequence motifs recovers only partial genes. Here we outline a strategy for recovering complete open reading frames from environmental DNA samples. PCR assays were designed to target the 59-base element family of recombination sites that flank gene cassettes associated with integrons. Using such assays, diverse gene cassettes could be amplified from the vast majority of environmental DNA samples tested. These gene cassettes contained complete open reading frames, the majority of which were associated with ribosome binding sites. Novel genes with clear homologies to phosphotransferase, DNA glycosylase, methyl transferase, and thiotransferase genes were identified. However, the majority of amplified gene cassettes contained open reading frames with no identifiable homologues in databases. Accumulation analysis of the gene cassettes amplified from soil samples showed no signs of saturation, and soil samples taken at 1-m intervals along transects demonstrated different amplification profiles. Taken together, the genetic novelty, steep accumulation curves, and spatial heterogeneity of genes recovered show that this method taps into a vast pool of unexploited genetic diversity. The success of this approach indicates that mobile gene cassettes and, by inference, integrons are widespread in natural environments and are likely to contribute significantly to bacterial diversity.

scholarly journals Tranosema rostrale ichnovirus repeat element genes display distinct transcriptional patterns in caterpillar and wasp hosts

2009 ◽  
Vol 90 (6) ◽  
pp. 1505-1514 ◽  
Author(s):  
Asieh Rasoolizadeh ◽  
Catherine Béliveau ◽  
Don Stewart ◽  
Conrad Cloutier ◽  
Michel Cusson
Keyword(s):  
Fat Body ◽  
Gene Dosage ◽  
Choristoneura Fumiferana ◽  
Gene Families ◽  
Transcript Abundance ◽  
Repeat Element ◽  
Open Reading Frames ◽  
Regulation Of Transcription ◽  
Lepidopteran Host ◽  
Reading Frames

The endoparasitic wasp Tranosema rostrale transmits an ichnovirus to its lepidopteran host, Choristoneura fumiferana, during parasitization. As shown for other ichnoviruses, the segmented dsDNA genome of the T. rostrale ichnovirus (TrIV) features several multi-gene families, including the repeat element (rep) family, whose products display no known similarity to non-ichnovirus proteins, except for a homologue encoded by the genome of the Helicoverpa armigera granulovirus; their functions remain unknown. This study applied linear regression of efficiency analysis to real-time PCR quantification of transcript abundance for all 17 TrIV rep open reading frames (ORFs) in parasitized and virus-injected C. fumiferana larvae, as well as in T. rostrale ovaries and head–thorax complexes. Although transcripts were detected for most rep ORFs in infected caterpillars, two of them clearly outnumbered the others in whole larvae, with a tendency for levels to drop over time after infection. The genome segments bearing the three most highly expressed rep genes in parasitized caterpillars were present in higher proportions than other rep-bearing genome segments in TrIV DNA, suggesting a possible role for gene dosage in the regulation of transcription level. TrIV rep genes also showed important differences in the relative abundance of their transcripts in specific tissues (cuticular epithelium, the fat body, haemocytes and the midgut), implying tissue-specific roles for individual members of this gene family. Significantly, no rep transcripts were detected in T. rostrale head–thorax complexes, whereas some were abundant in ovaries. There, the transcription pattern was completely different from that observed in infected caterpillars, suggesting that some rep genes have wasp-specific functions.

scholarly journals High Genetic Variability of the agr Locus in Staphylococcus Species

2002 ◽  
Vol 184 (4) ◽  
pp. 1180-1186 ◽  
Author(s):  
Philippe Dufour ◽  
Sophie Jarraud ◽  
Francois Vandenesch ◽  
Timothy Greenland ◽  
Richard P. Novick ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Quorum Sensing ◽  
Sequence Divergence ◽  
Pcr Amplification ◽  
Variable Region ◽  
Cysteine Residue ◽  
Multiple Alignment ◽  
Open Reading Frames ◽  
Signal Transduction System ◽  
Reading Frames

ABSTRACT The agr quorum-sensing and signal transduction system was initially described in Staphylococcus aureus, where four distinct allelic variants have been sequenced. Western blotting suggests the presence of homologous loci in many other staphylococci, and this has been confirmed for S. epidermidis and S. lugdunensis. In this study we isolated agr-like loci from a range of staphylococci by using PCR amplification from primers common to the six published agr sequences and bracketing the most variable region, associated with quorum-sensing specificity. Positive amplifications were obtained from 14 of 34 staphylococcal species or subspecies tested. Sequences of the amplicons identified 24 distinct variants which exhibited extensive sequence divergence with only 10% of the nucleotides absolutely conserved on multiple alignment. This variability involved all three open reading frames involved in quorum sensing and signal transduction. However, these variants retained several protein signatures, including the conserved cysteine residue of the autoinducing peptide, with the exception of S. intermedius of pigeon origin, which contained a serine in place of cysteine at this position. We discuss hypotheses on the mode of action and the molecular evolution of the agr locus based on comparisons between the newly determined sequences.

scholarly journals Analysis of Expressed Sequence Tags from Uromyces appendiculatus Hyphae and Haustoria and Their Comparison to Sequences from Other Rust Fungi

2008 ◽  
Vol 98 (10) ◽  
pp. 1126-1135 ◽  
Author(s):  
D. P. Puthoff ◽  
A. Neelam ◽  
M. L. Ehrenfried ◽  
B. E. Scheffler ◽  
L. Ballard ◽  
...  
Keyword(s):  
Expressed Sequence Tags ◽  
Sequence Data ◽  
Cellular Function ◽  
Rust Fungi ◽  
Open Reading Frames ◽  
Uromyces Appendiculatus ◽  
Data Set ◽  
Uromyces Fabae ◽  
Expressed Sequence ◽  
Reading Frames

Hyphae, 2 to 8 days postinoculation (dpi), and haustoria, 5 dpi, were isolated from Uromyces appendiculatus infected bean leaves (Phaseolus vulgaris cv. Pinto 111) and a separate cDNA library prepared for each fungal preparation. Approximately 10,000 hyphae and 2,700 haustoria clones were sequenced from both the 5′ and 3′ ends. Assembly of all of the fungal sequences yielded 3,359 contigs and 927 singletons. The U. appendiculatus sequences were compared with sequence data for other rust fungi, Phakopsora pachyrhizi, Uromyces fabae, and Puccinia graminis. The U. appendiculatus haustoria library included a large number of genes with unknown cellular function; however, summation of sequences of known cellular function suggested that haustoria at 5 dpi had fewer transcripts linked to protein synthesis in favor of energy metabolism and nutrient uptake. In addition, open reading frames in the U. appendiculatus data set with an N-terminal signal peptide were identified and compared with other proteins putatively secreted from rust fungi. In this regard, a small family of putatively secreted RTP1-like proteins was identified in U. appendiculatus and P. graminis.

scholarly journals Nitrogen or Sulfur Starvation Differentially Affects Phycobilisome Degradation and Expression of the nblA Gene in Synechocystis Strain PCC 6803

2001 ◽  
Vol 183 (10) ◽  
pp. 2989-2994 ◽  
Author(s):  
Catherine Richaud ◽  
Gérald Zabulon ◽  
Annette Joder ◽  
Jean-Claude Thomas
Keyword(s):  
Sequence Data ◽  
Open Reading Frames ◽  
Northern Hybridization ◽  
Sulfur Starvation ◽  
P Limitation ◽  
Kanamycin Cassette ◽  
N Starvation ◽  
Pcc 7942 ◽  
Reading Frames ◽  
Pcc 6803

ABSTRACT Nitrogen (N) limitation in cyanobacteria is well documented: a reduced growth rate is observed, accompanied by a cessation of phycobiliprotein synthesis and an ordered degradation of phycobilisomes (PBS). This leads to a dramatic bleaching phenomenon known as chlorosis. In Synechococcus strain PCC 7942, bleaching due to PBS degradation is also observed under sulfur (S) or phosphorus (P) limitation, and all three are under the control of the nblAgene product, a 59-amino-acid polypeptide which is overexpressed under N, S, and P starvation (J. L. Collier, and A. R. Grossman, EMBO J. 13:1039–1047, 1994). Cyanobase sequence data forSynechocystis strain PCC 6803 indicate the presence of two tandem open reading frames (sll0452 and sll0453) homologous tonblA. We cloned the two genes, identified a unique 5′ mRNA end suggestive of a single transcription start site, and studiednblA expression under conditions of N or S starvation by Northern hybridization: transcripts were detected only under N starvation (no signal is detected in replete medium or with S starvation), whether nblA1 or nblA2 was used as a probe. Mutations in nblA1 and nblA2 were constructed by insertion of a kanamycin cassette; both mutations were nonbleaching under N starvation. Synechocystis strain PCC 6803 does not bleach under S starvation, consistent with the absence ofnblA induction in these conditions. These results were confirmed by analysis of the PBS components: sequential degradation of phycocyanin and associated linkers was observed only under conditions of N starvation. This indicates differences betweenSynechocystis strain PCC 6803 and Synechococcusstrain PCC 7942 in their regulatory and signaling pathways leading to N- and S-starved phenotypes.

scholarly journals Cloning and Genetic Analyses of the Bacteriocin 41 Determinant Encoded on the Enterococcus faecalis Pheromone-Responsive Conjugative Plasmid pYI14: a Novel Bacteriocin Complemented by Two Extracellular Components (Lysin and Activator)

2008 ◽  
Vol 190 (6) ◽  
pp. 2075-2085 ◽  
Author(s):  
Haruyoshi Tomita ◽  
Elizabeth Kamei ◽  
Yasuyoshi Ike
Keyword(s):  
Enterococcus Faecalis ◽  
Sequence Data ◽  
Open Reading Frames ◽  
Conjugative Plasmid ◽  
Cell Surface Receptor ◽  
Bacteriocin Activity ◽  
Lytic Enzymes ◽  
Repeat Structure ◽  
Surface Receptor ◽  
Reading Frames

ABSTRACT The conjugative plasmid pYI14 (61 kbp) was isolated from Enterococcus faecalis YI714, a clinical isolate. pYI14 conferred a pheromone response on its host and encoded bacteriocin 41 (bac41). Bacteriocin 41 (Bac41) only showed activity against E. faecalis. Physical mapping of pYI14 showed that it consisted of EcoRI fragments A to P. The clone pHT1100, containing EcoRI fragments A (12.6 kbp) and H (3.5 kbp), conferred the bacteriocin activity on E. faecalis strains. Genetic analysis showed that the determinant was located in a 6.6-kbp region within the EcoRI AH fragments. Six open reading frames (ORFs) were identified in this region and designated ORF7 (bacL1 ) ORF8 (bacL2 ), ORF9, ORF10, ORF11 (bacA), and ORF12 (bacI). They were aligned in this order and oriented in the same direction. ORFs bacL1 , bacL2 , bacA, and bacI were essential for expression of the bacteriocin in E. faecalis. Extracellular complementation of bacteriocin expression was possible for bacL1 and -L2 and bacA mutants. bacL1 and -L2 and bacA encoded bacteriocin component L and activator component A, respectively. The products of these genes are secreted into the culture medium and extracellularly complement bacteriocin expression. bacI encoded immunity, providing the host with resistance to its own bacteriocin activity. The bacL1 -encoded protein had significant homology with lytic enzymes that attack the gram-positive bacterial cell wall. Sequence data for the deduced bacL1 -encoded protein suggested that it has a domain structure consisting of an N-terminal signal peptide, a second domain with the enzymatic activity, and a third domain with a three-repeat structure directing the proenzyme to its cell surface receptor.

scholarly journals Identification and analysis of proton-translocating pyrophosphatases in the methanogenic archaeonMethanosarcina mazei

Archaea ◽  
2002 ◽  
Vol 1 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Sebastian Bäumer ◽  
Sabine Lentes ◽  
Gerhard Gottschalk ◽  
Uwe Deppenmeier
Keyword(s):  
Specific Activity ◽  
Sequence Data ◽  
Sequence Similarity ◽  
Open Reading Frames ◽  
Inorganic Pyrophosphatase ◽  
Amino Acid Sequence Similarity ◽  
Sequence Alignments ◽  
Multiple Sequence ◽  
Inorganic Pyrophosphate ◽  
Reading Frames

Analysis of genome sequence data from the methanogenic archaeonMethanosarcina mazeiGö1 revealed the existence of two open reading frames encoding proton-translocating pyrophosphatases (PPases). These open reading frames are linked by a 750-bp intergenic region containing TC-rich stretches and are transcribed in opposite directions. The corresponding polypeptides are referred to as Mvp1 and Mvp2 and consist of 671 and 676 amino acids, respectively. Both enzymes represent extremely hydrophobic, integral membrane proteins with 15 predicted transmembrane segments and an overall amino acid sequence similarity of 50.1%. Multiple sequence alignments revealed that Mvp1 is closely related to eukaryotic PPases, whereas Mvp2 shows highest homologies to bacterial PPases. Northern blot experiments with RNA from methanol-grown cells harvested in the mid-log growth phase indicated that only Mvp2 was produced under these conditions. Analysis of washed membranes showed that Mvp2 had a specific activity of 0.34 U mg (protein)–1. Proton translocation experiments with inverted membrane vesicles prepared from methanol-grown cells showed that hydrolysis of 1 mol of pyrophosphate was coupled to the translocation of about 1 mol of protons across the cytoplasmic membrane. Appropriate conditions formvp1 expression could not be determined yet. The pyrophosphatases ofM. mazeiGö1 represent the first examples of this enzyme class in methanogenic archaea and may be part of their energy-conserving system. Abbreviations: DCCD,N,N′-dicyclohexylcarbodiimide; PPase, inorganic pyrophosphatase; PPi, inorganic pyrophosphate; Δp, proton motive force.

scholarly journals Target enrichment of long open reading frames and ultraconserved elements to link microevolution and macroevolution in non-model organisms

2021 ◽  
Author(s):  
Claudia Ortiz-Sepulveda ◽  
Mathieu Genete ◽  
Christelle Blassiau ◽  
Cécile Godé ◽  
Christian Albrecht ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Sequence Data ◽  
Early Stage ◽  
Phylogenetic Analyses ◽  
Open Reading Frames ◽  
Model Organisms ◽  
Recent Common Ancestor ◽  
Ultraconserved Elements ◽  
Most Recent Common Ancestor ◽  
Reading Frames

Despite the increasing accessibility of high-throughput sequencing, obtaining high-quality genomic data on non-model organisms without proximate well-assembled and annotated genomes remains challenging. Here we describe a workflow that takes advantage of distant genomic resources and ingroup transcriptomes to select and jointly enrich long open reading frames (ORFs) and ultraconserved elements (UCEs) from genomic samples for integrative studies of microevolutionary and macroevolutionary dynamics. This workflow is applied to samples of the African unionid bivalve tribe Coelaturini (Parreysiinae) at basin and continent-wide scales. Our results indicate that ORFs are efficiently captured without prior identification of intron-exon boundaries. The enrichment of UCEs was less successful, but nevertheless produced a substantial dataset. Exploratory continent-wide phylogenetic analyses with ORF supercontigs (>515,000 parsimony informative sites) resulted in a fully resolved phylogeny, the backbone of which was also retrieved with UCEs (>11,000 informative sites), although some branches lack support in the latter case. Variant calling on the exome of Coelaturini from the Malawi Basin produced ~2,000 SNPs per population pair. Nucleotide diversity and population differentiation was low compared to previous estimates in mollusks, but comparable to those in recently diversifying Malawi cichlids and other taxa at an early stage of speciation. Skimming non-specific sequence data obtained for Coelaturini of the Malawi Basin, we reconstructed the maternally-inherited mitogenome, which displays an identical gene order to that of the most recent common ancestor of Unionidae. Overall, our workflow and results provide exciting perspectives for the development of integrative genomic studies on micro- and macroevolutionary dynamics in non-model organisms.

scholarly journals Human β-defensin 4 – defensin without the “twist”

2016 ◽  
Vol 62 (3) ◽  
pp. 349-361
Author(s):  
Adam Prahl ◽  
Marzena Pazgier ◽  
Jerry Alexandratos ◽  
Jacek Lubkowski
Keyword(s):  
Chemokine Receptors ◽  
Solution Structure ◽  
Analytical Ultracentrifugation ◽  
Open Reading Frames ◽  
Structural Description ◽  
Limited Information ◽  
E Coli ◽  
Bactericidal Properties ◽  
Solution Studies ◽  
Reading Frames

β-defensins are small, cysteine-rich, cationic peptides that contribute to various processes related to both arms of host defense, the innate and adaptive immunities. All β-defensins are potent antimicrobials with activity targeting a broad range of pathogens. Some human β-defensins (hBDs) are also capable of binding and activating specific chemokine receptors, leading to chemotaxis of receptor-presenting cells. Two receptors identified as targets of specific human β-defensins are CCR2 and CCR6, both members of the seven-transmembrane family of chemokine receptors. Currently, around 50 open reading frames (ORFs) identified in the human genome encode proteins that have signatures characteristic of β-defensins. Of those, only three, hBD1-3, have been thoroughly characterized to date, including a detailed structural description of their molecules. In addition, limited information on biological and bactericidal properties is available for hBD4, as well as the solution structure of hBD6. The crystal structure of hBD4, determined here at resolution of 1.60 Å, indicates significant structural differences between this molecule and those reported previously for other hBDs. Crystallographic studies indicate a possibility of unique dimerization of hBD4, confirmed by solution studies using analytical ultracentrifugation. In contrast to hBD1-3, hBD4 does not induce CCR6-mediated chemotaxis. This observation can be attributed to an unusual conformation of the hBD4 N-terminus. In agreement with previously published reports, hBD4 was shown to be a potent antibacterial agent, as demonstrated by results of assays with E. coli ATCC 25922 cells.

scholarly journals Genomic and Morphological Features of a Banchine Polydnavirus: Comparison with Bracoviruses and Ichnoviruses

2007 ◽  
Vol 81 (12) ◽  
pp. 6491-6501 ◽  
Author(s):  
Renée Lapointe ◽  
Kohjiro Tanaka ◽  
Walter E. Barney ◽  
James B. Whitfield ◽  
Jonathan C. Banks ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Genome Size ◽  
Genome Sequence ◽  
Protein Tyrosine Phosphatase ◽  
Size Range ◽  
Tyrosine Phosphatase ◽  
Gene Families ◽  
Open Reading Frames ◽  
Genomic Features ◽  
Reading Frames

ABSTRACT Many ichneumonid and braconid endoparasitoids inject a polydnavirus (PDV) into their caterpillar hosts during oviposition. The viral entities carried by wasps of these families are referred to as “ichnoviruses” (IVs) and “bracoviruses” (BVs), respectively. All IV genomes characterized to date are found in wasps of the subfamily Campopleginae; consequently, little is known about PDVs found in wasps of the subfamily Banchinae, the only other ichneumonid taxon thus far shown to carry these viruses. Here we report on the genome sequence and virion morphology of a PDV carried by the banchine parasitoid Glypta fumiferanae. With an aggregate genome size of ∼290 kb and 105 genome segments, this virus displays a degree of genome segmentation far greater than that reported for BVs or IVs. The size range of its genome segments is also lower than those in the latter two groups. As reported for other PDVs, the predicted open reading frames of this virus cluster into gene families, including the protein tyrosine phosphatase (PTP) and viral ankyrin (ank) families, but phylogenetic analysis indicates that ank genes of the G. fumiferanae virus are not embedded within the IV lineage, while its PTPs and those of BVs form distinct clusters. The banchine PDV genome also encodes a novel family of NTPase-like proteins displaying a pox-D5 domain. The unique genomic features of the first banchine virus examined, along with the morphological singularities of its virions (IV-like nucleocapsids, but enveloped in groups like some of the BVs), suggest that they could have an origin distinct from those of IVs and BVs.

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