scholarly journals Phylogenetic Analysis of the Incidence of lux Gene Horizontal Transfer in Vibrionaceae

2008 ◽  
Vol 190 (10) ◽  
pp. 3494-3504 ◽  
Author(s):  
Henryk Urbanczyk ◽  
Jennifer C. Ast ◽  
Allison J. Kaeding ◽  
James D. Oliver ◽  
Paul V. Dunlap
Keyword(s):  
Phylogenetic Analysis ◽  
Horizontal Transfer ◽  
Vibrio Vulnificus ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Vibrio Splendidus ◽  
Photobacterium Leiognathi ◽  
Photobacterium Damselae ◽  
Phylogenetic Divergence ◽  
Distinctive Phenotype

ABSTRACT Horizontal gene transfer (HGT) is thought to occur frequently in bacteria in nature and to play an important role in bacterial evolution, contributing to the formation of new species. To gain insight into the frequency of HGT in Vibrionaceae and its possible impact on speciation, we assessed the incidence of interspecies transfer of the lux genes (luxCDABEG), which encode proteins involved in luminescence, a distinctive phenotype. Three hundred three luminous strains, most of which were recently isolated from nature and which represent 11 Aliivibrio, Photobacterium, and Vibrio species, were screened for incongruence of phylogenies based on a representative housekeeping gene (gyrB or pyrH) and a representative lux gene (luxA). Strains exhibiting incongruence were then subjected to detailed phylogenetic analysis of horizontal transfer by using multiple housekeeping genes (gyrB, recA, and pyrH) and multiple lux genes (luxCDABEG). In nearly all cases, housekeeping gene and lux gene phylogenies were congruent, and there was no instance in which the lux genes of one luminous species had replaced the lux genes of another luminous species. Therefore, the lux genes are predominantly vertically inherited in Vibrionaceae. The few exceptions to this pattern of congruence were as follows: (i) the lux genes of the only known luminous strain of Vibrio vulnificus, VVL1 (ATCC 43382), were evolutionarily closely related to the lux genes of Vibrio harveyi; (ii) the lux genes of two luminous strains of Vibrio chagasii, 21N-12 and SB-52, were closely related to those of V. harveyi and Vibrio splendidus, respectively; (iii) the lux genes of a luminous strain of Photobacterium damselae, BT-6, were closely related to the lux genes of the lux-rib 2 operon of Photobacterium leiognathi; and (iv) a strain of the luminous bacterium Photobacterium mandapamensis was found to be merodiploid for the lux genes, and the second set of lux genes was closely related to the lux genes of the lux-rib 2 operon of P. leiognathi. In none of these cases of apparent HGT, however, did acquisition of the lux genes correlate with phylogenetic divergence of the recipient strain from other members of its species. The results indicate that horizontal transfer of the lux genes in nature is rare and that horizontal acquisition of the lux genes apparently has not contributed to speciation in recipient taxa.

scholarly journals Phylogenetic analysis of the genus Aeromonas based on two housekeeping genes

2004 ◽  
Vol 54 (5) ◽  
pp. 1511-1519 ◽  
Author(s):  
L. Soler ◽  
M. A. Yáñez ◽  
M. R. Chacon ◽  
M. G. Aguilera-Arreola ◽  
V. Catalán ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Phylogenetic Relationships ◽  
Housekeeping Genes ◽  
Nucleotide Sequences ◽  
Aeromonas Salmonicida ◽  
Species Level ◽  
Substitution Rates ◽  
Aeromonas Veronii ◽  
Taxonomic Organization ◽  
Phylogenetic Divergence

The phylogenetic relationships of all known species of the genus Aeromonas, and especially Aeromonas bestiarum and Aeromonas salmonicida, were investigated on 70 strains using the rpoD sequence, which encodes the σ 70 factor. This analysis was complemented with the sequence of gyrB, which has already proven useful for determining the phylogenetic relationships in the genus. Nucleotide sequences of rpoD and gyrB showed that both genes had similar substitution rates (<2 %) and a similar number of variable positions (34 % for rpoD versus 32 % for gyrB). Strain groupings by analysis of rpoD, gyrB and a combination of both genes were consistent with the taxonomic organization of all Aeromonas species described to date. However, the simultaneous analysis of both clocks improved the reliability and the power to differentiate, in particular, closely related taxa. At the inter-species level, gyrB showed a better resolution for differentiating Aeromonas sp. HG11/Aeromonas encheleia and Aeromonas veronii/Aeromonas culicicola/Aeromonas allosaccharophila, while rpoD more clearly differentiated A. salmonicida from A. bestiarum. The analysis of rpoD provided initial evidence for clear phylogenetic divergence between the latter two species.

scholarly journals Diverse Horizontally-Acquired Gene Clusters Confer Sucrose Utilization to Different Lineages of the Marine Pathogen Photobacterium damselae subsp. damselae

Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1244
Author(s):  
Saqr Abushattal ◽  
Ana Vences ◽  
Alba V. Barca ◽  
Carlos R. Osorio
Keyword(s):  
Comparative Genomics ◽  
Horizontal Transfer ◽  
Hot Spot ◽  
Housekeeping Genes ◽  
Gene Clusters ◽  
Marine Animals ◽  
The Family ◽  
Photobacterium Damselae ◽  
Comparative Genomics Analysis ◽  
Sucrose Utilization

The ability to metabolize sucrose is a variable trait within the family Vibrionaceae. The marine bacterium Photobacterium damselae subsp. damselae (Pdd), pathogenic for marine animals and humans, is generally described as negative for sucrose utilization (Scr−). Previous studies have reported sucrose-utilizing isolates (Scr+), but the genetic basis of this variable phenotype remains uncharacterized. Here, we carried out the genome sequencing of five Scr+ and two Scr−Pdd isolates and conducted a comparative genomics analysis with sixteen additional Pdd genomes sequenced in previous studies. We identified two different versions of a four-gene cluster (scr cluster) exclusive of Scr+ isolates encoding a PTS system sucrose-specific IIBC component (scrA), a fructokinase (scrK), a sucrose-6-phosphate hydrolase (scrB), and a sucrose operon repressor (scrR). A scrA deletion mutant did not ferment sucrose and was impaired for growth with sucrose as carbon source. Comparative genomics analyses suggested that scr clusters were acquired by horizontal transfer by different lineages of Pdd and were inserted into a recombination hot-spot in the Pdd genome. The incongruence of phylogenies based on housekeeping genes and on scr genes revealed that phylogenetically diverse gene clusters for sucrose utilization have undergone extensive horizontal transfer among species of Vibrio and Photobacterium.

scholarly journals Assessment of common housekeeping genes as reference for gene expression studies using RT-qPCR in mouse choroid plexus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kim Hoa Ho ◽  
Annarita Patrizi
Keyword(s):  
Gene Expression ◽  
Choroid Plexus ◽  
Sensory Deprivation ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Experimental Conditions ◽  
Brain Repair ◽  
Expression Studies ◽  
Testing Algorithms ◽  
Gene Expression Studies

AbstractChoroid plexus (ChP), a vascularized secretory epithelium located in all brain ventricles, plays critical roles in development, homeostasis and brain repair. Reverse transcription quantitative real-time PCR (RT-qPCR) is a popular and useful technique for measuring gene expression changes and also widely used in ChP studies. However, the reliability of RT-qPCR data is strongly dependent on the choice of reference genes, which are supposed to be stable across all samples. In this study, we validated the expression of 12 well established housekeeping genes in ChP in 2 independent experimental paradigms by using popular stability testing algorithms: BestKeeper, DeltaCq, geNorm and NormFinder. Rer1 and Rpl13a were identified as the most stable genes throughout mouse ChP development, while Hprt1 and Rpl27 were the most stable genes across conditions in a mouse sensory deprivation experiment. In addition, Rpl13a, Rpl27 and Tbp were mutually among the top five most stable genes in both experiments. Normalisation of Ttr and Otx2 expression levels using different housekeeping gene combinations demonstrated the profound effect of reference gene choice on target gene expression. Our study emphasized the importance of validating and selecting stable housekeeping genes under specific experimental conditions.

scholarly journals Diversity unearthed by the estimated molecular phylogeny and ecologically quantitative characteristics of uncultured Ehrlichia bacteria in Haemaphysalis ticks, Japan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hongru Su ◽  
Eri Onoda ◽  
Hitoshi Tai ◽  
Hiromi Fujita ◽  
Shigetoshi Sakabe ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
Core Genome ◽  
Phylogenetic Analyses ◽  
Taxonomic Status ◽  
Housekeeping Genes ◽  
Pcr Screening ◽  
Taxonomic Profiling ◽  
Quantitative Characteristics

AbstractEhrlichia species are obligatory intracellular bacteria transmitted by arthropods, and some of these species cause febrile diseases in humans and livestock. Genome sequencing has only been performed with cultured Ehrlichia species, and the taxonomic status of such ehrlichiae has been estimated by core genome-based phylogenetic analysis. However, many uncultured ehrlichiae exist in nature throughout the world, including Japan. This study aimed to conduct a molecular-based taxonomic and ecological characterization of uncultured Ehrlichia species or genotypes from ticks in Japan. We first surveyed 616 Haemaphysalis ticks by p28-PCR screening and analyzed five additional housekeeping genes (16S rRNA, groEL, gltA, ftsZ, and rpoB) from 11 p28-PCR-positive ticks. Phylogenetic analyses of the respective genes showed similar trees but with some differences. Furthermore, we found that V1 in the V1–V9 regions of Ehrlichia 16S rRNA exhibited the greatest variability. From an ecological viewpoint, the amounts of ehrlichiae in a single tick were found to equal approx. 6.3E+3 to 2.0E+6. Subsequently, core-partial-RGGFR-based phylogenetic analysis based on the concatenated sequences of the five housekeeping loci revealed six Ehrlichia genotypes, which included potentially new Ehrlichia species. Thus, our approach contributes to the taxonomic profiling and ecological quantitative analysis of uncultured or unidentified Ehrlichia species or genotypes worldwide.

scholarly journals Mechanism of Metronidazole Resistance inHelicobacter pylori: Comparison of the rdxA Gene Sequences in 30 Strains

2000 ◽  
Vol 44 (8) ◽  
pp. 2207-2210 ◽  
Author(s):  
Nadia Maggi Solcà ◽  
Marco Valerio Bernasconi ◽  
Jean-Claude Piffaretti
Keyword(s):  
Phylogenetic Analysis ◽  
Helicobacter Pylori ◽  
Amino Acid ◽  
Resistant Strain ◽  
Point Mutations ◽  
Housekeeping Genes ◽  
Amino Acid Substitutions ◽  
Metronidazole Resistance ◽  
Nucleotide Mutation ◽  
Nucleotide Insertion

ABSTRACT The rdxA gene of 30 independently isolatedHelicobacter pylori strains was sequenced. A comparison of the rdxA sequences revealed a higher percentage of amino acid substitutions in the corresponding protein than in other housekeeping genes. Out of 122 point mutations, 41 were missense and 4 were nonsense. A resistant strain with a nucleotide insertion in therdxA sequence was also found. With the exception of the point mutations and the insertion generating a stop signal, no particular nucleotide mutation or amino acid substitution could be associated to metronidazole resistance. Moreover, phylogenetic analysis of the 30 nucleotide sequences did not demonstrate specific clusters associated with the resistance phenotype.

Real-time RT-PCR analysis of housekeeping genes in human skeletal muscle following acute exercise

2004 ◽  
Vol 18 (2) ◽  
pp. 226-231 ◽  
Author(s):  
Douglas J. Mahoney ◽  
Kate Carey ◽  
Ming-Hua Fu ◽  
Rodney Snow ◽  
David Cameron-Smith ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Real Time ◽  
Healthy Subjects ◽  
Acute Exercise ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Cycle Ergometry ◽  
Pcr Analysis ◽  
28S Rrna ◽  
Rt Pcr

Studies examining gene expression with RT-PCR typically normalize their mRNA data to a constitutively expressed housekeeping gene. The validity of a particular housekeeping gene must be determined for each experimental intervention. We examined the expression of various housekeeping genes following an acute bout of endurance (END) or resistance (RES) exercise. Twenty-four healthy subjects performed either a interval-type cycle ergometry workout to exhaustion (∼75 min; END) or 300 single-leg eccentric contractions (RES). Muscle biopsies were taken before exercise and 3 h and 48 h following exercise. Real-time RT-PCR was performed on β-actin, cyclophilin (CYC), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and β2-microglobulin (β2M). In a second study, 10 healthy subjects performed 90 min of cycle ergometry at ∼65% of V̇o2 max, and we examined a fifth housekeeping gene, 28S rRNA, and reexamined β2M, from muscle biopsy samples taken immediately postexercise. We showed that CYC increased 48 h following both END and RES exercise (3- and 5-fold, respectively; P < 0.01), and 28S rRNA increased immediately following END exercise (2-fold; P = 0.02). β-Actin trended toward an increase following END exercise (1.85-fold collapsed across time; P = 0.13), and GAPDH trended toward a small yet robust increase at 3 h following RES exercise (1.4-fold; P = 0.067). In contrast, β2M was not altered at any time point postexercise. We conclude that β2M and β-actin are the most stably expressed housekeeping genes in skeletal muscle following RES exercise, whereas β2M and GAPDH are the most stably expressed following END exercise.

Methodologies for specific intron and exon RNA localization in cultured cells by haptenized and fluorochromized probes

1993 ◽  
Vol 104 (4) ◽  
pp. 1187-1197 ◽  
Author(s):  
R.W. Dirks ◽  
F.M. van de Rijke ◽  
S. Fujishita ◽  
M. van der Ploeg ◽  
A.K. Raap
Keyword(s):  
In Situ Hybridization ◽  
Cell Lines ◽  
Cultured Cells ◽  
Direct Detection ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Immediate Early ◽  
High Signal ◽  
Pretreatment Conditions

We have determined optimal conditions for the detection of mRNA sequences in cultured cells by nonradioactive in situ hybridization. For this purpose a number of different cell lines have been used: rat 9G cells for the detection of human cytomegalovirus immediate early mRNA, and HeLa as well as 5637 carcinoma cells for the detection of housekeeping gene mRNAs. Extensive optimization of fixation and pretreatment conditions revealed that most intense hybridization signals are obtained when cells are grown on glass microscope slides, fixed with a mixture of formaldehyde and acetic acid, pretreated with pepsin and denatured prior to hybridization. In addition, we also studied the potential of fluorochromized probes for the direct detection of multiple RNA sequences. The optimized in situ hybridization procedure revealed that immediate early mRNA transcripts are, in addition to a cytoplasmic localization, localized within nuclei of rat 9G cells. Double hybridization experiments showed that intron and exon sequences colocalize within the main nuclear signal. In addition, the presence of small, intron-specific, fluorescent spots scattered around the main nuclear signals indicates that intron sequences which are spliced out can be visualized. Additional information about the functioning of cells could be obtained by the detection of mRNA simultaneously with bromodeoxyuridine, incorporated during S-phase, or its cognate protein. The sensitivity of these methods is such that mRNAs of abundantly expressed housekeeping genes can be detected in a variety of cell lines with high signal to noise ratios.

scholarly journals Housekeeping Genes for Phylogenetic Analysis of Eutherian Relationships

2006 ◽  
Vol 23 (8) ◽  
pp. 1493-1503 ◽  
Author(s):  
Morgan Kullberg ◽  
Maria A. Nilsson ◽  
Ulfur Arnason ◽  
Eric H. Harley ◽  
Axel Janke
Keyword(s):  
Phylogenetic Analysis ◽  
Housekeeping Genes

scholarly journals Molecular data analysis of selected housekeeping and informational genes from nineteen Campylobacter jejuni genomes

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 87 ◽  
Author(s):  
Vathsala Mohan ◽  
Mark Stevenson
Keyword(s):  
Information Processing ◽  
Campylobacter Jejuni ◽  
Genetic Recombination ◽  
Bacterial Species ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Molecular Data ◽  
Sequence Type ◽  
Molecular Characteristics ◽  
Research Article

Campylobacter jejuni (C. jejuni) is a rapidly evolving bacterial species with massive genetic recombination potential to generate niche specific genotypes. Generally the housekeeping gene lineage has been evidenced to undergo lateral gene transfer and recombination fairly frequently compared to the information processing gene lineage. During such exchanges, gene amelioration takes place over time acquiring the host genomes’ molecular characteristics. In this study fifty genes that comprised twenty five housekeeping lineage genes and twenty five information processing lineage genes from nineteen C. jejuni genomes were studied. These nineteen genomes included seven C. jejuni isolates that belonged to the same genotype or multilocus sequence type ST-474. The genes from both lineages were tested for recombination and the guanine-cytosine (GC) variation. This paper details about the data collected and the analyses performed in the corresponding research article entitled ”Campylobacter jejuni genomes exhibit notable GC variation within housekeeping genes”. Further, this paper provides details on the results that are not included in the research paper to provide completeness to the study conducted. The gene sequences from the seven C. jejuni ST-474 isolates were submitted to the GenBank and the corresponding gene IDs are provided for referencing purposes.

scholarly journals Investigation of Different Commercially Available Real Time-Polymerase Chain Reaction Kits for SARS-CoV-2 Diagnosis

2021 ◽  
Author(s):  
Rajeev Kumar Jain ◽  
Nagaraj Perumal ◽  
Rakesh Shrivastava ◽  
Kamlesh Kumar Ahirwar ◽  
Jaya Lalwani ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Internal Control ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Specific Gene ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Gene Target ◽  
Polymerase Chain

Introduction: The whole world is facing an ongoing global health emergency of COVID-19 disease caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). Real-Time Reverse Transcription-Polymerase Chain Reaction (RT-PCR) is a gold standard in the detection of SARS-CoV-2 infection. Presently, many single tube multiple gene target RT-PCR kits have been developed and are commercially available for Coronavirus Disease 2019 (COVID-19) diagnosis. Aim: To evaluate the performance of seven COVID-19 RT-PCR kits (DiagSure, Meril, VIRALDTECT II, TruPCR, Q-line, Allplex and TaqPath) which are commercially available for COVID-19 RT-PCR diagnosis. Materials and Methods: This observational study was conductedat the State Virology Laboratory (SVL), Gandhi Medical College, Bhopal, Madhya Pradesh, India. Seven commercially available kits have been evaluated on the basis of: (i) number of SARS-CoV-2 specific gene target; (ii) human housekeeping genes as internal control; (iii) RT-PCR run time; and (iv) kit performances to correctly detect SARS-CoV-2 positive and negative RNA samples. A total of 50 RNA samples (left over RNA) were included, master mix preparation, template addition and RT-PCR test has been performed according to kits literature. At the end of PCR run, mean and standard deviation of obtained cut-off of all kits were calculated using Microsoft Excel. Results: All seven RT-PCR kits performed satisfactory regarding the reproducibility and they could correctly identify 30 positive and 20 negative RNA samples. RNA samples (group C) having low viral loads with a high Cycle threshold (Ct) value (>30) were also detected by all these seven kits. Obtained Ct values of each group was in parallel range in comparison with the initial testing Ct values. Kits were found to be superior which contains primers and probes for three SARS-CoV-2 specific gene targets, have human housekeeping gene as internal control and taking less time to complete RT-PCR. Conclusion: All seven COVID-19 RT-PCR kits included in this study demonstrated satisfactory performance and can be used for the routine molecular diagnosis of COVID-19 disease.

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