Mapping of a gene in Vibrio cholerae that determines the antigenic structure of cholera toxin

Saunders, David W.; Schanbacher, K J; Bramucci, M G

doi:10.1128/iai.38.3.1109-1116.1982

Cited by 12 publications

(11 citation statements)

References 35 publications

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“…Toxin regulatory differences between various strains and mutants of V. cholerae have previously complicated the genetic analysis of the toxin structural genes (2,19,20,29,30). For example, Saunders et al (29) reported the mapping of a V. cholerae gene, vct, which is responsible for an antigenic variation in the cholera toxin produced by the two El Tor strains 3083 and RJ1 (the latter is the same as strain RV79).…”

Section: Discussionmentioning

confidence: 99%

“…Since our data place the toxin structural genes between these two loci, it is possible that Saunders et al did not recognize certain important vet or ctx recombinant classes in their analysis. The conflicting data might also be due to the fact that Saunders et al (29,30) used, in these genetic analyses, heterologous crosses between two different El Tor strains, RJ1 and 3083.…”

Section: Discussionmentioning

confidence: 99%

“…Plasmid pJM290.14 was first mobilized into an Smr RV79 derivative, JM7943. JM7943(pJM290.14) was then superinfected with plasmid pPHlJI (30), and Kmr Gmr Smr colonies were selected. Since pJM290.14 and pPHlJI are incompatible, these triply resistant colonies represented recombinants that had recombined the ActxA23P Kmr allele onto the RV79 chromosome via crossover events between homologous DNA flanking the ctx regions.…”

Section: Methodsmentioning

confidence: 99%

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Genetic mapping of Vibrio cholerae enterotoxin structural genes

Sporecke¹,

Castro²,

Mekalanos³

1984

J Bacteriol

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The structural genes which constitute the cholera toxin operon, ctxAB, were genetically mapped in the Vibrio cholerae El Tor strain RV79. This strain of V. cholerae contains two copies of the ctx operon located on a 7-kilobase-pair tandemly duplicated region. We began by isolating a vibriophage VcA1 insertion mutation in one of the two ctxA genes located in this region. The mutant carrying this ctxA::VcA1 insertion, DC24, was converted to a VcA1-facilitated donor by introduction of the conjugal plasmid pSJ15, which carries an inserted copy of a defective VcA1-like prophage. The donor characteristics of DC24(pSJ15) indicated that the ctxA::VcA1 insertion mutation was near the trp region of the V. cholerae chromosome. Subsequent RV79 three-factor crosses were performed between VcA1-facilitated donors and recipient strains carrying one of two structural gene mutations in ctx, either ActxA23P Kmr or Actx-7922. The former was constructed by an in vivo marker exchange procedure and could be scored either by its kanamycin resistance phenotype or by its lack of DNA sequences homologous to the ctxA region. The Actx-7922 mutation is a total deletion of both ctx copies of strain RV79. The three-factor cross data strongly suggest that the two ctx loci of RV79 map between the nal and his genes of V. cholerae in the trp nal his linkage group. Physical analysis and heterologous crosses between an RV79 El Tor donor and a 569B classical recipient indicates that one of the two 569B ctx operon copies maps in the same region as the RV79 ctx loci (i.e., linked to nal). Together with previously published observations, these data show that the ctx structural genes are not closely linked to other genes known to affect toxin production in V. cholerae.Toxinogenic strains of Vibrio cholerae produce an extracellular heat-labile protein that is primarily responsible for the diarrheal syndrome observed in Asiatic cholera (8). Cholera toxin is now recognized as the prototype for a growing family of protein enterotoxins that produce their toxic effects via the activation of adenylate cyclase in eucaryotic cells (4,5,9). The heat-labile enterotoxin of Escherichia coli also belongs to this family, and recent DNA sequence analysis has shown the heat-labile enterotoxin genes to be 78% homologous to the cholera toxin genes (5; deWilde, Nature [London], in press). However, the LT operon eltAB appears to be exclusively located on plasmids (7, 28), while the data suggest that the cholera toxin operon ctxAB is located on the bacterial chromosome. This conclusion has been based primarily on the absence of demonstrable plasmids in toxinogenic V. cholerae strains of either the classical or El Tor biotypes (15,22).Although a variety of laboratories have isolated mutants and genetically mapped mutations that affect toxin production in the highly toxinogenic classical strain 569B, all of these mutations have turned out to be regulatory mutations (2,10,12,17,19,20). The explanation for this failure to obtain structural gene mutations in ctx in this particular ...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Genetic mapping of Vibrio cholerae enterotoxin structural genes

Sporecke¹,

Castro²,

Mekalanos³

1984

J Bacteriol

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“…The transposon-facilitated recombination system of Johnson and Romig (4) was used in conjunction with an RJ1 donor strain and a 3083-2 recipient strain to map the position of tox-1000. The procedural details of the mating experiments have been previously described (6). Strain MB2020(pSJ13) (RJ1: :Tnl-24, vct-i, tox-1000, and rif-5001) was used as the donor strain.…”

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confidence: 99%

Genetic Mapping of the tox-1000 Locus of Vibrio cholerae El Tor Strain RJ1

Saunders

Bramucci

1983

Infect Immun

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“…In conjugal matings, Tfr donors transfer the bacterial chromosome to recipient bacteria in an oriented and sequential manner from an origin corresponding to the site of insertion of the transposon in the donor chromosome. Isogenic Tfr donor strains with P plasmids containing the appropriate transposon in opposite orientations can, therefore, mobilize chromosomal genes in conjugal matings from a common origin but with opposite polarities (10,16,17). In the studies reported here, we used transposon-facilitated recombination mediated by transposon Tnl or transposon TnS for genetic mapping of biotype determinants of V. cholerae.…”

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confidence: 99%

Mapping of chromosomal genes that determine the El Tor biotype in Vibrio cholerae

Green¹,

Newland²,

Holmes³

1983

Infect Immun

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The El Tor biotype of Vibrio cholerae has several characteristics that differentiate it from the classical biotype of V. cholerae. Among these are production of soluble hemolysin(s), a cell-associated hemagglutinin for chicken erythrocytes, resistance to polymyxin B, and resistance to bacteriophages of Mukerjee group IV. In the present study, we located the determinants for hemolysin (hly), chicken erythrocyte hemagglutinin (cha), and polymyxin B resistance (pmx) on the genetic map of V. cholerae. Transposon-facilitated recombination was used to perform conjugal matings between El Tor donor strains and classical recipient strains of V. cholerae. Recombinants were selected that had inherited specific nutritional markers from the donor strains and streptomycin resistance from the recipient strains. The reconibinants were tested for the presence or absence of the unselected donor markers hly, cha, and pmx. These three El Tor biotype markers were found to be closely linked to each other and were located between the pyrA-201 and his-2 loci on the genetic map of V. cholerae.on July 31, 2020 by guest http://iai.asm.org/ Downloaded from

show abstract

Mapping of a gene in Vibrio cholerae that determines the antigenic structure of cholera toxin

Cited by 12 publications

References 35 publications

Genetic mapping of Vibrio cholerae enterotoxin structural genes

Genetic mapping of Vibrio cholerae enterotoxin structural genes

Genetic Mapping of the tox-1000 Locus of Vibrio cholerae El Tor Strain RJ1

Mapping of chromosomal genes that determine the El Tor biotype in Vibrio cholerae

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