Expression of the sigma35 and cry2AB genes involved in Bacillus thuringiensis virulence

There are several genes involved in Bacillus thuringiensis sporulation. The regulation and expression of these genes results in an upregulation in Cry protein production, and this is responsible for the death of insect larvae infected by Bacillus thuringiensis. Gene expression was monitored in Bacillus thuringiensis during three developmental phases. DNA macroarrays were constructed for selected genes whose sequences are available in the GenBank database. These genes were hybridized to cDNA sequences from B. thuringiensis var. kurstaki HD-1. cDNA probes were synthesized by reverse transcription from B. thuringiensis RNA templates extracted during the exponential (log) growth, stationary and sporulation phases, and labeled with 33PadCTP. Two genes were differentially expressed levels during the different developmental phases. One of these genes is related to sigma factor (sigma35), and the other is a cry gene (cry2Ab). There were differences between the differential levels of expression of various genes and among the expression detected for different combinations of the sigma factor and cry2Ab genes. The maximum difference in expression was observed for the gene encoding sigma35 factor in the log phase, which was also expressed at a high level during the sporulation phase. The cry2Ab gene was only expressed at a high level in the log phase, but at very low levels in the other phases when compared to the sigma35.

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High-Frequency Phenotypic Reversion and Pathogenicity of an Acyclovir-Resistant Herpes Simplex Virus Mutant

Journal of Virology ◽

10.1128/jvi.77.3.2282-2286.2003 ◽

2003 ◽

Vol 77 (3) ◽

pp. 2282-2286 ◽

Cited By ~ 23

Author(s):

Anthony Griffiths ◽

Donald M. Coen

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

High Frequency ◽

Insertion Mutation ◽

Gene Encoding ◽

Low Levels ◽

Virus Mutant ◽

Simplex Virus ◽

High Level ◽

Phenotypic Reversion

ABSTRACT A double-guanine-insertion mutation within a run of guanines in the herpes simplex virus gene encoding thymidine kinase (TK) was previously found in an acyclovir-resistant clinical isolate. This mutation was engineered into strain KOS, and stocks were generated from single plaques. Plaque autoradiography revealed that most plaques in such stocks exhibited low levels of TK activity, while ∼3% of plaques exhibited high levels of TK activity, indicating a remarkably high frequency of phenotypic reversion. This virus was able to reactivate from latency in mouse ganglia; a fraction of the reactivating virus expressed a high level of TK activity due to an additional G insertion, suggesting that the observed genetic instability contributed to pathogenicity.

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The Introduction into Bacillus sphaericus of the Bacillus thuringiensis subsp. medellin cyt1Ab1 Gene Results in Higher Susceptibility of Resistant Mosquito Larva Populations to B. sphaericus

Applied and Environmental Microbiology ◽

10.1128/aem.64.10.3910-3916.1998 ◽

1998 ◽

Vol 64 (10) ◽

pp. 3910-3916 ◽

Cited By ~ 22

Author(s):

I. Thiéry ◽

S. Hamon ◽

A. Delécluse ◽

S. Orduz

Keyword(s):

Bacillus Thuringiensis ◽

Culex Pipiens ◽

Recombinant Strain ◽

Mosquito Larva ◽

Shuttle Vector ◽

Bacillus Sphaericus ◽

The Other ◽

Binary Toxin ◽

Gene Encoding ◽

Flanking Sequences

ABSTRACT The fragment containing the gene encoding the cytolytic Cyt1Ab1 protein from Bacillus thuringiensis subsp.medellin and its flanking sequences (I. Thiery, A. Delécluse, M. C. Tamayo, and S. Orduz, Appl. Environ. Microbiol. 63:468–473, 1997) was introduced into Bacillus sphaericus toxic strains 2362, 2297, and Iab872 by electroporation with the shuttle vector pMK3. Only small amounts of the protein were produced in recombinant strains 2362 and Iab872. The protein was detected in these strains only by Western blotting and immunodetection with antibody raised against Cyt1Ab1 protein. Large amounts of Cyt1Ab1 protein were produced in B. sphaericus recombinant strain 2297, and there was an additional crystal, other than that of the binary toxin, within the exosporium. The production of the Cyt1Ab1 protein in addition to the binary toxin did not increase the larvicidal activity of theB. sphaericus recombinant strain against susceptible mosquito populations of Culex pipiens orAedes aegypti. However, it partially restored (10 to 20 times) susceptibility of the resistant mosquito populations of C. pipiens (SPHAE) and Culex quinquefasciatus (GeoR) to the binary toxin. The Cyt1Ab1 protein produced in recombinantB. thuringiensis SPL407(pcyt1Ab1) was synthesized in two types of crystal—one round and with various dense areas, surrounded by an envelope, and the other a regular cuboid crystal, very similar to that found in the B. sphaericus recombinant strain.

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When Teacher Enthusiasm Is Authentic or Inauthentic: Lesson Profiles of Teacher Enthusiasm and Relations to Students’ Emotions

AERA Open ◽

10.1177/2332858418782967 ◽

2018 ◽

Vol 4 (2) ◽

pp. 233285841878296 ◽

Cited By ~ 4

Author(s):

Melanie M. Keller ◽

Eva S. Becker ◽

Anne C. Frenzel ◽

Jamie L. Taxer

Keyword(s):

Teaching Effectiveness ◽

Well Being ◽

The Other ◽

Teaching Behaviors ◽

Teacher Enthusiasm ◽

Low Levels ◽

High Level ◽

Level 2

It was recently proposed that teacher enthusiasm encompasses an experienced component as well as a behaviorally displayed component. Aiming to validate this proposition, the present study utilized lesson diaries to explore patterns of teacher-reported experienced enthusiasm and student-reported enthusiastic teaching behaviors and to investigate whether those patterns were related to students’ enjoyment and boredom. Findings imply that the two enthusiasm components do not always co-occur. Four lesson profiles were identified: (1) experienced enthusiasm and enthusiastic teaching coinciding at a high level, (2) teachers reporting high levels of experienced enthusiasm but not being perceived as enthusiastic, (3) teachers being perceived as enthusiastic but not reporting high levels of experienced enthusiasm, and (4) low levels of experienced enthusiasm and enthusiastic teaching. The first pattern was superior to the other profiles regarding students’ emotions. Study findings are discussed with respect to teachers’ emotional well-being and teaching effectiveness.

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The Origins of Industrial Conciliation and Arbitration

International Review of Social History ◽

10.1017/s0020859000002558 ◽

1964 ◽

Vol 9 (2) ◽

pp. 237-254 ◽

Cited By ~ 6

Author(s):

V. L. Allen

Keyword(s):

Commodity Markets ◽

The Other ◽

Textile Workers ◽

Trade Unionism ◽

The North ◽

Labour Costs ◽

Low Levels ◽

High Level ◽

The Cost ◽

Wage Cuts

Trade unionism has always involved the settlement of industrial disputes by negotiations between workers' representatives and employers. On occasions in the eighteenth and first half of the nineteenth centuries demands made by workers or employers were granted without question by the other side; at other times the demands were rejected out of hand and this was acquiesced in by the other side. In between these extremes lay a number of possible outcomes. Demands were sometimes conceded after strikes or lockouts or they were moderated and then accepted. The precise outcome depended upon the state of the labour market, and hence the degree of labour organization, and the cost position of the employers. These factors not only varied over time but differed in their intensity between industries and firms at any one point of time. The extreme situations occurred at high and low levels of employment. In the competition for labour, which a high level of employment implies, employers readily gave way to collective demands but as commodity markets deteriorated and the volume of production declined, they at first resisted claims which would have increased labour costs and then deliberately set out to cut wages, lengthen hours and intensify work. Workers commonly resisted initial attempts to reduce labour costs so that a spate of strikes and lockouts ensued. At the onset of the depression in 1819 and at the first suggestion of wage reductions the Lancashire miners, the North Staffordshire potters and the Nottingham framework knitters all responded by striking. The Glasgow cotton spinners resisted wage cuts in 1837 as did the London building workers and miners and textile workers in the midlands and north in 1841 and the typographical workers in 1846. Frequently, however, these disputes resulted in compromise settlements which were superseded by other compromises as trade conditions got worse.

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ςK Can Negatively RegulatesigE Expression by Two Different Mechanisms during Sporulation of Bacillus subtilis

Journal of Bacteriology ◽

10.1128/jb.181.13.4081-4088.1999 ◽

1999 ◽

Vol 181 (13) ◽

pp. 4081-4088 ◽

Cited By ~ 23

Author(s):

Bin Zhang ◽

Paolo Struffi ◽

Lee Kroos

Keyword(s):

Bacillus Subtilis ◽

Rna Polymerase ◽

Sigma Factor ◽

Mother Cell ◽

Transcriptional Activity ◽

The Other ◽

Mutant Form ◽

Gene Encoding ◽

Negative Effect ◽

Cell Gene Expression

ABSTRACT Temporal and spatial gene regulation during Bacillus subtilis sporulation involves the activation and inactivation of multiple sigma subunits of RNA polymerase in a cascade. In the mother cell compartment of sporulating cells, expression of thesigE gene, encoding the earlier-acting sigma factor, ςE, is negatively regulated by the later-acting sigma factor, ςK. Here, it is shown that the negative feedback loop does not require SinR, an inhibitor of sigEtranscription. Production of ςK about 1 h earlier than normal does affect Spo0A, which when phosphorylated is an activator of sigE transcription. A mutation in thespo0A gene, which bypasses the phosphorelay leading to the phosphorylation of Spo0A, diminished the negative effect of early ςK production on sigE expression early in sporulation. Also, early production of ςK reduced expression of other Spo0A-dependent genes but not expression of the Spo0A-independent ald gene. In contrast, bothsigE and ald were overexpressed late in development of cells that fail to make ςK. Theald promoter, like the sigE promoter, is believed to be recognized by ςA RNA polymerase, suggesting that ςK may inhibit ςA activity late in sporulation. To exert this negative effect, ςKmust be transcriptionally active. A mutant form of ςKthat associates with core RNA polymerase, but does not direct transcription of a ςK-dependent gene, failed to negatively regulate expression of sigE or aldlate in development. On the other hand, the negative effect of early ςK production on sigE expression early in sporulation did not require transcriptional activity of ςK RNA polymerase. These results demonstrate that ςK can negatively regulate sigE expression by two different mechanisms, one observed when ςK is produced earlier than normal, which does not require ςKto be transcriptionally active and affects Spo0A, and the other observed when ςK is produced at the normal time, which requires ςK RNA polymerase transcriptional activity. The latter mechanism facilitates the switch from ςE to ςK in the cascade controlling mother cell gene expression.

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Complete Sequence and Organization of pFR260, the Bacillus thuringiensis INTA Fr7-4 Plasmid Harboring Insecticidal Genes

Journal of Molecular Microbiology and Biotechnology ◽

10.1159/000451056 ◽

2017 ◽

Vol 27 (1) ◽

pp. 43-54 ◽

Cited By ~ 2

Author(s):

Laura E. Navas ◽

Ariel F. Amadio ◽

Elio M. Ortiz ◽

Diego H. Sauka ◽

Graciela B. Benintende ◽

...

Keyword(s):

Bacillus Thuringiensis ◽

Pathogenicity Island ◽

Complete Sequence ◽

Accession Number ◽

Cry Protein ◽

Gene Encoding ◽

Rep Protein ◽

Initiation Of Replication ◽

Gc Skew ◽

Dna Strand

We report the complete sequence and analysis of pFR260, a novel megaplasmid of 260,595 bp from the Bacillus thuringiensis strain INTA Fr7-4 isolated in Argentina. It carries 7 insecticidal genes: 3 cry8 copies previously reported, 2 vip1, and 2 vip2. Also, it carries a gene encoding a putative atypical Cry protein. These genes are arranged in a region of approximately 105 kbp in size with characteristics of a pathogenicity island with a potential coleopteran-specific insecticide profile. DNA strand composition asymmetry, as determined by GC skew analysis, and the presence of a Rep protein involved in the initiation of replication suggest a bidirectional theta mechanism of replication. In addition, many genes involved in conjugation and a CRISPR-Cas system were detected. The pFR260 sequence was deposited in GenBank under accession number KX258624.

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Fate of Bacillus thuringiensis strains in different insect larvae

Canadian Journal of Microbiology ◽

10.1139/w04-087 ◽

2004 ◽

Vol 50 (11) ◽

pp. 973-975 ◽

Cited By ~ 20

Author(s):

Marise Tanaka Suzuki ◽

Didier Lereclus ◽

Olivia M. Nagy Arantes

Keyword(s):

Bacillus Thuringiensis ◽

Bacterial Growth ◽

Insect Larvae ◽

Cry Protein ◽

Insect Pathogen ◽

Vegetative Cells ◽

Crystal Proteins ◽

Favorable Conditions ◽

Insecticidal Crystal Proteins

In favorable conditions Bacillus thuringiensis spores germinate and vegetative cells multiply, whereas in unfavorable conditions Bacillus thuringiensis sporulates and produces insecticidal crystal proteins. The development of B. thuringiensis strains was investigated in the larvae of insects belonging to the orders Lepidoptera and Diptera. Bacillus thuringiensis strains able to kill the insects did not always multiply in cadavers. Strains with no specificity to kill the insect sometimes multiplied when the insects were killed mechanically. These results indicate that some insect larvae represent an environment that favors the germination of B. thuringiensis spores and the multiplication of vegetative cells; however, there was no correlation between the toxin specificity and the specificity of the host.Key words: Bacillus thuringiensis, Cry protein, insect pathogen, bacterial growth.

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Importance of Cry Proteins in Biotechnology: Initially a Bioinsecticide, Now a Vaccine Adjuvant

Life ◽

10.3390/life11100999 ◽

2021 ◽

Vol 11 (10) ◽

pp. 999

Author(s):

Maria Cristina Gonzalez-Vazquez ◽

Ruth Abril Vela-Sanchez ◽

Norma Elena Rojas-Ruiz ◽

Alejandro Carabarin-Lima

Keyword(s):

Immune Response ◽

Bacillus Thuringiensis ◽

Specific Antigen ◽

Structural Homology ◽

Insect Larvae ◽

Cry Protein ◽

Parasporal Crystal ◽

Cry Proteins ◽

Experimental Animal Models ◽

Specific Antigens

A hallmark of Bacillus thuringiensis bacteria is the formation of one or more parasporal crystal (Cry) proteins during sporulation. The toxicity of these proteins is highly specific to insect larvae, exerting lethal effects in different insect species but not in humans or other mammals. The aim of this review is to summarize previous findings on Bacillus thuringiensis, including the characteristics of the bacterium, its subsequent contribution to biotechnology as a bioinsecticide due to the presence of Cry proteins, and its potential application as an adjuvant. In several studies, Cry proteins have been administered together with specific antigens to immunize experimental animal models. The results have shown that these proteins can enhance immunogenicity by generating an adequate immune response capable of protecting the model against an experimental infectious challenge, whereas protection is decreased when the specific antigen is administered without the Cry protein. Therefore, based on previous results and the structural homology between Cry proteins, these molecules have arisen as potential adjuvants in the development of vaccines for both animals and humans. Finally, a model of the interaction of Cry proteins with different components of the immune response is proposed.

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Role of the Alternative Sigma Factor ςS in Expression of the AlkS Regulator of thePseudomonas oleovorans Alkane Degradation Pathway

Journal of Bacteriology ◽

10.1128/jb.181.6.1748-1754.1999 ◽

1999 ◽

Vol 181 (6) ◽

pp. 1748-1754 ◽

Cited By ~ 32

Author(s):

Inés Canosa ◽

Luis Yuste ◽

Fernando Rojo

Keyword(s):

Rna Polymerase ◽

Stationary Phase ◽

Sigma Factor ◽

Degradation Pathway ◽

Exponential Phase ◽

Alternative Sigma Factor ◽

Alkane Degradation ◽

Gene Coding ◽

Low Levels ◽

High Level

ABSTRACT The AlkS protein activates transcription from the PalkBpromoter, allowing the expression of a number of genes required for the assimilation of alkanes in Pseudomonas oleovorans. We have identified the promoter from which the alkS gene is transcribed, PalkS, and analyzed its expression under different conditions and genetic backgrounds. Transcription fromPalkS was very low during the exponential phase of growth and increased considerably when cells reached the stationary phase. ThePalkS −10 region was similar to the consensus described for promoters recognized by Escherichia coli RNA polymerase bound to the alternative sigma factor ςS, which directs the expression of many stationary-phase genes. Reporter strains containing PalkS-lacZ transcriptional fusions showed thatPalkS promoter is very weakly expressed in aPseudomonas putida strain bearing an inactivated allele of the gene coding for ςS, rpoS. WhenPalkS was transferred to E. coli, transcription started at the same site and expression was higher in stationary phase only if ςS-RNA polymerase was present. The low levels of AlkS protein generated in the absence of ςS were enough to support a partial induction of the PalkB promoter. The −10 and −35 regions of PalkS promoter also show some similarity to the consensus recognized by ςD-RNA polymerase, the primary form of RNA polymerase. We propose that in exponential phase PalkS is probably recognized both by ςD-RNA polymerase (inefficiently) and by ςS-RNA polymerase (present at low levels), leading to low-level expression of the alkS gene. ςS-RNA polymerase would be responsible for the high level of activity ofPalkS observed in stationary phase.

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Ethics in the Judiciary System of Bangladesh

Bangladesh Journal of Bioethics ◽

10.3329/bioethics.v1i2.9628 ◽

1970 ◽

Vol 1 (2) ◽

pp. 34-36

Author(s):

Mehedi Imam

Keyword(s):

Rule Of Law ◽

Judicial Independence ◽

Moral Values ◽

The Other ◽

Considerable Time ◽

Ethical Knowledge ◽

Judicial Practice ◽

Independent Judiciary ◽

Role Players ◽

High Level

In Bangladesh, demand for judicial independence in practice has been a much debated issue and the demand is fulfilled but expectation of people is not only limited to have an independent judiciary but to have an impartial system and cadre of people, which will administer justice rationally being free from fear or force. The independence of judiciary and the impartial judicial practice are related concepts, one cannot sustain without the other and here existence as well as the need of practicing impartiality is well recognized. But the art of practicing impartiality does not develop overnight as it’s related to development of one’s attitude. It takes a considerable time resulting from understanding, appreciating and acknowledging the moral values, ethics and professional responsibility. The judiciary includes Judges, Advocates mostly who are expected to demonstrate a high level of moral values and impartiality towards people seeking justice and ‘rule of law’. This is true that bench officers and clerks are also part of the process to ensure rule of law with same level of participation by the law enforcing agencies such as police. However the paper includes only those who either join judiciary as Judge/Magistrate or Advocate to explore level and extent of ethical knowledge they receive being key role players of the system. DOI: http://dx.doi.org/10.3329/bioethics.v1i2.9628 Bangladesh Journal of Bioethics 2010; 1(2): 34-36

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