Isolation and Characterization of a 1.7-kb Transposable Element from a Mutator Line of Maize

ABSTRACT We have cloned and sequenced a 1.7-kb Mu element from a Mutator line of maize and compared its structure to Mu1, a 1.4-kb element. With the exception of a 385-bp block of DNA present in the 1.7-kb element, these transposable elements are structurally similar, sharing terminally inverted and internal direct repeated sequences. Derivation of 1.4-kb elements from the 1.7-kb class via deletion of internal sequence is suggested by the finding that a portion of the extra DNA in Mu1.7 is part of a truncated direct repeat sequence in the 1.4-kb element. An abundant poly(A)+ RNA homologous to a portion of this extra DNA is present in several tissues of both Mutator and non-Mutator lines. Analysis of transcripts from an unstable mutant bronze1 (bz) allele containing a Mu1.7 element inserted in an exon of the gene detects three species of poly(A)+ RNA that hybridize to a Bz1 (Bronze) gene probe: the largest contains the entire Mu1.7 element in the Bz1 gene transcript; another appears to be a spliced, chimeric transcript; the smallest is normal size Bz1 mRNA. The latter is most likely encoded by the normal-size alleles detected by Southern analysis of tissue expressing purple pigment, suggesting that normal gene function is restored by excision of the Mu1.7 element.

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Yersinia enterocolitica ClpB Affects Levels of Invasin and Motility

Journal of Bacteriology ◽

10.1128/jb.182.19.5563-5571.2000 ◽

2000 ◽

Vol 182 (19) ◽

pp. 5563-5571 ◽

Cited By ~ 16

Author(s):

Julie L. Badger ◽

Briana M. Young ◽

Andrew J. Darwin ◽

Virginia L. Miller

Keyword(s):

Yersinia Enterocolitica ◽

Insertion Mutant ◽

Gene Transcript ◽

Null Mutant ◽

Early Stationary Phase ◽

Flagellin Gene ◽

Transposon Insertion ◽

Isolation And Characterization ◽

Mutant Phenotypes

ABSTRACT Expression of the Yersinia enterocolitica inv gene is dependent on growth phase and temperature. inv is maximally expressed at 23°C in late-exponential- to early-stationary-phase cultures. We previously reported the isolation of a Y. enterocolitica mutant (JB1A8v) that shows a decrease in invasin levels yet is hypermotile when grown at 23°C. JB1A8v has a transposon insertion within uvrC. Described here is the isolation and characterization of a clone that suppresses these mutant phenotypes of the uvrC mutant JB1A8v. This suppressing clone encodes ClpB (a Clp ATPase homologue). The Y. enterocolitica ClpB homologue is 30 to 40% identical to the ClpB proteins from various bacteria but is 80% identical to one of the two ClpB homologues ofYersinia pestis. AclpB::TnMax2 insertion mutant (JB69Qv) was constructed and determined to be deficient in invasin production and nonmotile when grown at 23°C. Analysis ofinv and fleB (flagellin gene) transcript levels in JB69Qv suggested that ClpB has both transcriptional and posttranscriptional effects. In contrast, a clpB null mutant, BY1v, had no effect on invasin levels or motility. A model accounting for these observations is presented.

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Isolation and characterization of recombinant DNA clones of avian retroviruses: size heterogeneity and instability of the direct repeat.

Journal of Virology ◽

10.1128/jvi.33.3.1026-1033.1980 ◽

1980 ◽

Vol 33 (3) ◽

pp. 1026-1033 ◽

Cited By ~ 36

Author(s):

G Ju ◽

L Boone ◽

A M Skalka

Keyword(s):

Recombinant Dna ◽

Direct Repeat ◽

Isolation And Characterization ◽

Size Heterogeneity

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Isolation and characterization of a highly repetitious inverted terminal repeat sequence from Oxytricha macronuclear DNA.

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.75.6.2626 ◽

1978 ◽

Vol 75 (6) ◽

pp. 2626-2630 ◽

Cited By ~ 12

Author(s):

G. Herrick ◽

R. D. Wesley

Keyword(s):

Repeat Sequence ◽

Terminal Repeat ◽

Inverted Terminal Repeat ◽

Isolation And Characterization ◽

Inverted Terminal Repeat Sequence ◽

Terminal Repeat Sequence

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Mutations in the lux Operon of Natural Dark Mutants in the Genus Vibrio

Applied and Environmental Microbiology ◽

10.1128/aem.01199-07 ◽

2007 ◽

Vol 74 (1) ◽

pp. 61-66 ◽

Cited By ~ 11

Author(s):

Elizabeth A. O'Grady ◽

Charles F. Wimpee

Keyword(s):

Insertion Sequence ◽

Stop Codon ◽

Point Mutations ◽

Gene Probe ◽

Bacterial Bioluminescence ◽

Isolation And Characterization ◽

Lux Operon ◽

Wide Range ◽

Natural Isolates

ABSTRACT Bacterial bioluminescence can display a wide range of intensities among strains, from very bright to undetectable, and it has been shown previously that there are nonluminous vibrios that possess lux genes. In this paper, we report the isolation and characterization of completely dark natural mutants in the genus Vibrio. Screening of over 600 Vibrio isolates with a luxA gene probe revealed that approximately 5% carried the luxA gene. Bioluminescence assays of the luxA-positive isolates, followed by repetitive extragenic palindromic-PCR fingerprinting, showed three unique genotypes that are completely dark. The dark mutants show a variety of lesions, including an insertion sequence, point mutations, and deletions. Strain BCB451 has an IS10 insertion sequence in luxA, a mutated luxE stop codon, and a truncated luxH. Strain BCB494 has a 396-bp deletion in luxC, and strain BCB440 has a frameshift in luxC. This paper represents the first molecular characterization of natural dark mutants and the first demonstration of incomplete lux operons in natural isolates.

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Characterization of Mycobacterium tuberculosis complex direct repeat sequence for use in cycling probe reaction.

Journal of Clinical Microbiology ◽

10.1128/jcm.34.12.2985-2989.1996 ◽

1996 ◽

Vol 34 (12) ◽

pp. 2985-2989 ◽

Cited By ~ 24

Author(s):

M L Beggs ◽

M D Cave ◽

C Marlowe ◽

L Cloney ◽

P Duck ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Mycobacterium Tuberculosis Complex ◽

Direct Repeat ◽

Repeat Sequence ◽

Tuberculosis Complex ◽

Direct Repeat Sequence

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Molecular Description and Industrial Potential of Tn6098Conjugative Transfer Conferring Alpha-Galactoside Metabolism inLactococcus lactis

Applied and Environmental Microbiology ◽

10.1128/aem.02283-10 ◽

2010 ◽

Vol 77 (2) ◽

pp. 555-563 ◽

Cited By ~ 28

Author(s):

Ronnie Machielsen ◽

Roland J. Siezen ◽

Sacha A. F. T. van Hijum ◽

Johan E. T. van Hylckama Vlieg

Keyword(s):

Integration Site ◽

Insertion Site ◽

Direct Repeat ◽

Repeat Sequence ◽

Recipient Strain ◽

Phenotypic Characterization ◽

Donor Strain ◽

Pcr Product ◽

Molecular Description

ABSTRACTA novel 51-kb conjugative transposon ofLactococcus lactis, designated Tn6098, encoding the capacity to utilize α-galactosides such as raffinose and stachyose, was identified and characterized. Alpha-galactosides are a dominant carbon source in many plant-derived foods. Most dairy lactococcus strains are unable to use α-galactosides as a growth substrate, yet many of these strains are known to have beneficial industrial traits. Conjugal transfer of Tn6098was demonstrated from the plant-derived donor strainL. lactisKF147 to the recipientL. lactisNZ4501, a derivative of the dairy model strainL. lactisMG1363. The integration of Tn6098into the genome of the recipient strain was confirmed by Illumina sequencing of the transconjugantL. lactisNIZO3921. The molecular structure of the integration site was confirmed by a PCR product spanning the insertion site. A 15-bp direct repeat sequence (TTATACCATAATTAC) is present on either side of Tn6098in the chromosome ofL. lactisKF147. One copy of this sequence is also present in theL. lactisMG1363 chromosome and represents the sole integration site. Phenotypic characterization of all strains showed that the transconjugant has not only acquired the ability to grow well in soy milk, a substrate rich in α-galactosides, but also has retained the flavor-forming capabilities of the recipient strainL. lactisMG1363. This study demonstrates how (induced) conjugation can be used to exploit the beneficial industrial traits of industrial dairy lactic acid bacteria in fermentation of plant-derived substrates.

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Isolation of pig mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase gene promoter: characterization of a peroxisome proliferator-responsive element

Biochemical Journal ◽

10.1042/bj3370329 ◽

1999 ◽

Vol 337 (2) ◽

pp. 329-335 ◽

Cited By ~ 7

Author(s):

José A. ORTIZ ◽

Judith MALLOLAS ◽

Carine NICOT ◽

Josep BOFARULL ◽

Joan C. RODRÍGUEZ ◽

...

Keyword(s):

Promoter Region ◽

Gene Promoter ◽

Direct Repeat ◽

Peroxisome Proliferator ◽

Transcription Start ◽

Promoter Characterization ◽

Isolation And Characterization ◽

Responsive Element

Low expression of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase gene during development correlates with an unusually low hepatic ketogenic capacity and lack of hyperketonaemia in piglets. Here we report the isolation and characterization of the 5´ end of the pig mitochondrial HMG-CoA synthase gene. The 581 bp region proximal to the transcription start site permits transcription of a reporter gene, confirming the function of the promoter. The pig mitochondrial HMG-CoA synthase promoter is trans-activated by the peroxisomal proliferator-activated receptor (PPAR), and a functional response element for PPAR (PPRE) has been localized in the promoter region. Pig PPRE is constituted by an imperfect direct repeat (DR-1) and a downstream sequence, both of which are needed to confer PPAR-sensitivity to a thymidine kinase promoter and to form complexes with PPAR·retinoid X receptor heterodimers. A role of PPAR trans-activation in starvation-associated induction of gene expression is suggested.

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