Genetic Studies Relating to the Production of Transformed Clones Diploid in the Tryptophan Region of the
            <i>Bacillus subtilis</i>
            Genome

Audit, Claudie; Anagnostopoulos, C.

doi:10.1128/jb.114.1.18-27.1973

Cited by 28 publications

(10 citation statements)

References 20 publications

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“…A merodiploid system in B. subtilis has recently been described by Audit and Anagnostopoulos (14,15). The merodiploid condition was observed after transformation or transduction to prototrophy of strains bearing the trpE26 mutation.…”

Section: Analysis Of Merodiploidsmentioning

confidence: 98%

Genetic aspects of bacterial endospore formation.

Piggot¹,

Coote²

1976

Bacteriological Reviews

405

283

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95 cysA14 60 ery-1 25 purA 49 metC3; 21 ura-1 c 42 ura-26 s 83 ura-1; 5 metC3 ' 54 lys-l' 44 trpC2 35 trpC2 33 Iys-1; 16 trpC2 56 lys-1 25 phe-1; 10 ilvCl RI = 0.1 12 hisAI RI s 0.2 47 ura-1; 1 metC3 12 ura-26 16 ura-1; 49 metC3 49 52 148 307 24 phe-12; 1 lys-l 49 B 49 49, 143, 334 49 244 49 a Linkage with vegetative markers is expressed as % cotransfer. Linkage between spo mutations is expressed as the recombination index (RI [170]). b A, J.A. Hoch, personal communication; B, M. Young, personal communication; C, P.J. Piggot, unpublished observations. I Assignment to locus is not certain, see text. d If 94U (reference 148) is the same as 94 (reference 257), then this has the same phenotype as spoIVC mutants described by Coote (49, 50), and the mutations should be placed in the spoIVC locus.

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Section: Analysis Of Merodiploidsmentioning

confidence: 98%

Genetic aspects of bacterial endospore formation.

Piggot¹,

Coote²

1976

Bacteriological Reviews

405

283

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“…The common element in all lysine-sensitive strains is redundancy of segment B. Stable merodiploids in which only the C segment is redundant are Lysres (1,3). Recent data indicate that lysine sensitivity is determined by the diploid state of a locus, not yet identified, close to the left-hand end point of the B segment.…”

Section: Tre-12 Homlamentioning

confidence: 99%

“…Strains of Bacillus subtilis carrying the trpE26 mutation possess certain properties which distinguish them from those of 168 origin (1,2,3). The most important ofthese features is their aptitude to give rise to merodiploid clones when transformed or transduced to tryptophan independence.…”

mentioning

confidence: 99%

Differences in the genetic structure of Bacillus subitilis strains carrying the trpE26 mutation and strain 168

Trowsdale¹,

Anagnostopoulos²

1976

J Bacteriol

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It was previously shown that in strains ofBacillus subtilis bearing the trpE26 mutation a chromosome segment (from trpD to ilvA) is translocated to a position near the thr region. Further PBS1-mediated transduction data have now revealed that these strains also possess an inversion of part of the chromosome from the origin of replication, down to the tre locus on one side and the cysB locus on the other. These data concern evidence oflinkage oftre-12 to markers in the translocation (hisH2, tyrAl, and metB3) as well as linkage of the cysB3 marker to thi-86, gly-133, and catA. They explain the previously observed absence of linkage of markers in the translocated segment to cysB3. The model proposed for the formation of merodiploids in trpE26 strains, which calls for the fusion of two genetic elements, is not incompatible with this new finding. Moreover, the model was found to be of more general significance. Evidence is presented that merodiploids may also be produced from 168 recipients and trpE26 donors by transduction, when selection is made for particular markers. The markers should be in the ilvA and thr regions. They are widely separated in the recipient 168 strain but are closely linked in the trpE26 donor as a result of the translocation. The diploids so produced are unstable, sensitive to L-lysine, and segregate rapidly.Strains of Bacillus subtilis carrying the trpE26 mutation possess certain properties which distinguish them from those of 168 origin (1, 2, 3). The most important ofthese features is their aptitude to give rise to merodiploid clones when transformed or transduced to tryptophan independence.In a recent paper we have shown that the trpE26 marker is the result ofthe translocation of a chromosome segment (12). The relevent evidence was obtained by studies on the replication order of markers, using the density transfer technique, and from the results of mapping experiments. Markers on a chromosome segment extending from trpD to ilvA replicated earlier in trpE26 strains, at about the same time as tre-12 and thr-5. These two markers (the replication times of which are close in strain 168) are situated on opposite sides of the bidirectionally replicating chromosome (5,9,14). Those markers normally flanking the region (trpE8 and citK7) replicated late, as usual. The results suggested that the trpD-ilvA segment was shifted in strains bearing the trpE26 marker to a position closer to the origin of replication, near tre or thr. Mapping experiments by PBS1 transduction, when both donor I Present address: Department of Microbiology, Scripps Clinic and Research Foundation, La Jolla, Calif. 92037. and recipient carried the trpE26 marker, clearly showed that the segment was removed from its normal position to a site near thr (i) aroB2 and citK7 were linked in these strains;(ii) linkage of cysB3 and thr-5 was lost; (iii) several markers in the translocation were linked to thr-5 and ald. However, similar transduction crosses failed to reveal linkage of the translocation to cysB3. These negative results hav...

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“…When a trpE26 strain is transforned or transduced with a donor of strain 168 origin, the Trp+ recombinants are unstable and are diploid for a section oftheir chromosome from thr-5 to ilvA (1,4). If maintained on media without tryptophan, the recombinants remain merodiploid for several subcultures and give rise to Trpsegregants when transferred to supplemented media (2,3).…”

mentioning

confidence: 99%

“…As far as the spoOA and spoOB loci are concemed, spoOA markers may be introduced into the recipient by transduction 99 with phage PBS1, when selection is made for trpE26', and markers from either locus may be introduced by transformation, using saturating concentrations of DNA (congression) from trpE26 strains (12,13). Stabilization of the unstable merodiploids may take place at a low frequency to give clones that are diploid for a shorter section of their chromosome, from trpE to ilvA (1,3). These clones are phenotypically Trp' and are haploid for the spoOA and spoOB regions.…”

mentioning

confidence: 99%

Evidence that spo0A mutations are recessive in spo0A-/spo0A+ merodiploid strains of Bacillus subtilis

Trowsdale¹,

Chen²,

Hoch³

1978

J Bacteriol

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The spoOA locus contains two types of closely linked mutations that block sporulation at stage 0: spoOA mutations (the most pleiotropic of the stage 0 markers) and spoOC mutations. It was previously thought that spoOA mutations were dominant in merodiploids of Bacillus subtilis, whereas spoOC mutations were recessive. We have shown that spoOA mutations were recessive when spoOA-IspoOA+ merodiploids were made in the genetic backgrounds of strains that were resistant to antibiotic produced by the wild-type strain. Reinvestigation of cultures of spoOA-IspoOA+ merodiploids constructed in the antibiotic-sensitive spoOA strain showed that they contained the spoOA allele at a low frequency, and they produced very few haploid Sposegregants. These facts indicated that the cultures contained mostly homogenotic (spo0A+/spo0A+) cells. The reason for the poor survival of the spoOA-IspoOA+ merodiploids in the genetic background

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Genetic Studies Relating to the Production of Transformed Clones Diploid in the Tryptophan Region of the Bacillus subtilis Genome

Cited by 28 publications

References 20 publications

Genetic aspects of bacterial endospore formation.

Genetic aspects of bacterial endospore formation.

Differences in the genetic structure of Bacillus subitilis strains carrying the trpE26 mutation and strain 168

Evidence that spo0A mutations are recessive in spo0A-/spo0A+ merodiploid strains of Bacillus subtilis

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