scholarly journals Extensive Proliferation of Transposable Elements in Heritable Bacterial Symbionts

2007 ◽  
Vol 190 (2) ◽  
pp. 777-779 ◽  
Author(s):  
Gordon R. Plague ◽  
Helen E. Dunbar ◽  
Phat L. Tran ◽  
Nancy A. Moran
Keyword(s):  
Transposable Elements ◽  
Insertion Sequence ◽  
Early Stage ◽  
Bacterial Symbionts ◽  
Is Elements ◽  
Bacterial Endosymbionts ◽  
Genomic Recombination

ABSTRACT We found that insertion sequence (IS) elements are unusually abundant in the relatively recently evolved bacterial endosymbionts of maize weevils. Because multicopy elements can facilitate genomic recombination and deletion, this IS expansion may represent an early stage in the genomic reduction that is common in most ancient endosymbionts.

scholarly journals Insertion sequence-excision enhancer removes transposable elements from bacterial genomes and induces various genomic deletions

2011 ◽  
Vol 2 (1) ◽  
Author(s):  
Masahiro Kusumoto ◽  
Tadasuke Ooka ◽  
Yoshiaki Nishiya ◽  
Yoshitoshi Ogura ◽  
Takashi Saito ◽  
...  
Keyword(s):  
Transposable Elements ◽  
Insertion Sequence ◽  
Bacterial Genomes ◽  
Genomic Deletions

Deteriorated biofilm-forming capacity and electroactivity of Shewanella oneidnsis MR-1 induced by insertion sequence (IS) elements

2020 ◽  
Vol 156 ◽  
pp. 112136
Author(s):  
Lei Cheng ◽  
Di Min ◽  
Dong-Feng Liu ◽  
Ting-Ting Zhu ◽  
Kai-Li Wang ◽  
...  
Keyword(s):  
Insertion Sequence ◽  
Is Elements

The insertion sequence element ISRm2011-2 belongs to the IS630-Tcl family of transposable elements and is abundant in Rhizobium meliloti

Gene ◽  
1995 ◽  
Vol 163 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Werner Selbitschka ◽  
Walter Arnold ◽  
Doris Jording ◽  
Bob Kosier ◽  
Nicolas Toro ◽  
...  
Keyword(s):  
Transposable Elements ◽  
Insertion Sequence ◽  
Rhizobium Meliloti ◽  
Sequence Element ◽  
Insertion Sequence Element

scholarly journals Regulation and Adaptive Evolution of Lactose Operon Expression in Lactobacillus delbrueckii

2002 ◽  
Vol 184 (4) ◽  
pp. 928-935 ◽  
Author(s):  
Luciane Lapierre ◽  
Beat Mollet ◽  
Jacques-Edouard Germond
Keyword(s):  
Insertion Sequence ◽  
Selective Pressure ◽  
Constitutive Expression ◽  
Fermented Milk ◽  
Lactobacillus Delbrueckii ◽  
Repressor Gene ◽  
Is Elements ◽  
Gene Insertion ◽  
Palindromic Structure ◽  
Operon Expression

ABSTRACT Lactobacillus delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis are both used in the dairy industry as homofermentative lactic acid bacteria in the production of fermented milk products. After selective pressure for the fast fermentation of milk in the manufacture of yogurts, L. delbrueckii subsp. bulgaricus loses its ability to regulate lac operon expression. A series of mutations led to the constitutive expression of the lac genes. A complex of insertion sequence (IS) elements (ISL4 inside ISL5), inserted at the border of the lac promoter, induced the loss of the palindromic structure of one of the operators likely involved in the binding of regulatory factors. A lac repressor gene was discovered downstream of the β-galactosidase gene of L. delbrueckii subsp. lactis and was shown to be inactivated by several mutations in L. delbrueckii subsp. bulgaricus. Regulatory mechanisms of the lac gene expression of L. delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis were compared by heterologous expression in Lactococcus lactis of the two lac promoters in front of a reporter gene (β-glucuronidase) in the presence or absence of the lac repressor gene. Insertion of the complex of IS elements in the lac promoter of L. delbrueckii subsp. bulgaricus increased the promoter's activity but did not prevent repressor binding; rather, it increased the affinity of the repressor for the promoter. Inactivation of the lac repressor by mutations was then necessary to induce the constitutive expression of the lac genes in L. delbrueckii subsp. bulgaricus.

scholarly journals Transposable Element Loads in a Bacterial Symbiont of Weevils Are Extremely Variable

2008 ◽  
Vol 74 (24) ◽  
pp. 7832-7834 ◽  
Author(s):  
Kevin M. Dougherty ◽  
Gordon R. Plague
Keyword(s):  
Homologous Recombination ◽  
Transposable Elements ◽  
Transposable Element ◽  
Insertion Sequence ◽  
Bacterial Symbiont ◽  
Genomic Variation ◽  
Bacterial Endosymbiont

ABSTRACT Not only are transposable elements profuse in the bacterial endosymbiont of maize weevils, but we found that their quantities also vary ∼10-fold among individual weevils. Because multicopy elements can facilitate homologous recombination, this insertion sequence (IS) load variability suggests that these essentially asexual bacteria may exhibit substantial intraspecific genomic variation.

scholarly journals Complete DNA Sequence of Yersinia enterocolitica Serotype 0:8 Low-Calcium-Response Plasmid Reveals a New Virulence Plasmid-Associated Replicon

2001 ◽  
Vol 69 (7) ◽  
pp. 4627-4638 ◽  
Author(s):  
Norma J. Snellings ◽  
Michael Popek ◽  
Luther E. Lindler
Keyword(s):  
Yersinia Enterocolitica ◽  
Insertion Sequence ◽  
Open Reading Frames ◽  
Virulence Plasmid ◽  
Calcium Response ◽  
Is Elements ◽  
New Genes ◽  
Low Calcium ◽  
Reading Frames ◽  
Plasmid Replicons

ABSTRACT The complete nucleotide sequence and organization of theYersinia enterocolitica serotype 0:8 low-calcium-response (LCR) plasmid, pYVe8081, were determined. The 67,720-bp plasmid encoded all the genes known to be part of the LCR stimulon except for ylpA. Eight of 13 intact open reading frames of unknown function identified in pYVe8081 had homologues in Yersinia pestis plasmid pCD1 or inY. enterocolitica serotype 0:9 plasmid pYVe227. A region of approximately 17 kbp showed no DNA identity to pCD1 or pYVe227 and contained six potential new genes, a possible new replicon, and two intact insertion sequence (IS) elements. One intact IS element, ISYen1, was a new IS belonging to the IS256 family. Several vestigial IS elements appeared different from the IS distribution seen in the other LCR plasmids. The RepA proteins encoded by Y. enterocoliticaserotype 0:8 pYVeWA and pYVe8081 were identical. The putative pYVe8081 replicon showed significant homology to the IncL/M replicon of pMU407.1 but was only distantly related to the replicons of pCD1 and pYVe227. In contrast, the putative partitioning genes of pYVe8081 showed 97% DNA identity to the spy/sopABC loci of pCD1 and pYVe227. Sequence analysis suggests thatYersinia LCR plasmids are from a common ancestor but that Y. enterocolitica serotype 0:8 plasmid replicons may have evolved independently via cointegrate formation following a transposition event. The change in replicon structure is predicted to change the incompatibility properties of Y. enterocolitica serotype 0:8 plasmids from those of Y. enterocolitica serotype 0:9 and Y. pestis LCR plasmids.

scholarly journals High-Temperature-Induced Transposition of Insertion Elements in Burkholderia multivorans ATCC 17616

2005 ◽  
Vol 71 (4) ◽  
pp. 1822-1828 ◽  
Author(s):  
Yoshiyuki Ohtsubo ◽  
Hiroyuki Genka ◽  
Harunobu Komatsu ◽  
Yuji Nagata ◽  
Masataka Tsuda
Keyword(s):  
High Temperature ◽  
Insertion Sequence ◽  
Experimental Protocol ◽  
Specific Primer ◽  
Transposition Frequency ◽  
Burkholderia Multivorans ◽  
Is Elements ◽  
Insertion Elements ◽  
High Temperature Condition ◽  
Starvation Conditions

ABSTRACT An efficient and quantitative method to analyze the transposition of various insertion sequence (IS) elements in Burkholderia multivorans ATCC 17616 was devised. pGEN500, a plasmid carrying a Bacillus subtilis-derived sacB gene, was introduced into ATCC 17616 cells, and 25% of their sucrose-resistant derivatives were found to carry various IS elements on pGEN500. A PCR-based experimental protocol, in which a mixture of several specific primer pairs was used, revealed that pGEN500 captured, in addition to five previously reported IS elements (IS401, IS402, IS406, IS407, and IS408), three novel IS elements, ISBmu1, ISBmu2, and ISBmu3. The global transposition frequency of these IS elements was enhanced more than sevenfold under a high-temperature condition (42°C) but not under oxidative stress or starvation conditions. To our knowledge, this is the first report demonstrating the elevated transposition activities of several IS elements at a high temperature. The efficient experimental protocol developed in this study will be useful in quantitatively and simultaneously investigating various IS elements, as well as in capturing novel functional mobile elements from a wide variety of bacteria.

scholarly journals Crucial Role for Insertion Sequence Elements in Lactobacillus helveticus Evolution as Revealed by Interstrain Genomic Comparison

2009 ◽  
Vol 76 (1) ◽  
pp. 212-220 ◽  
Author(s):  
Pawel Kaleta ◽  
John O'Callaghan ◽  
Gerald F. Fitzgerald ◽  
Thomas P. Beresford ◽  
R. Paul Ross
Keyword(s):  
Insertion Sequence ◽  
Bacterial Genome ◽  
Lactobacillus Helveticus ◽  
Open Reading Frames ◽  
Comparative Genome Hybridization ◽  
Genome Plasticity ◽  
Genomic Comparison ◽  
Is Elements ◽  
Accelerated Evolution ◽  
Sequence Elements

ABSTRACT Lactobacillus helveticus is a versatile dairy bacterium found to possess heterogeneous genotypes depending on the ecosystem from which it was isolated. The recently published genome sequence showed the remarkable flexibility of its structure, demonstrated by a substantial level of insertion sequence (IS) element expansion in association with massive gene decay. To assess this diversity and examine the level of genome plasticity within the L. helveticus species, an array-based comparative genome hybridization (aCGH) experiment was designed in which 10 strains were analyzed. The aCGH experiment revealed 16 clusters of open reading frames (ORFs) flanked by IS elements. Four of these ORFs are associated with restriction/modification which may have played a role in accelerated evolution of strains in a commercially intensive ecosystem undoubtedly challenged through successive phage attack. Furthermore, analysis of the IS-flanked clusters demonstrated that the most frequently encountered ISs were also those most abundant in the genome (IS1201, ISL2, ISLhe1, ISLhe2, ISLhe65, and ISLhe63). These findings contribute to the overall viewpoint of the versatile character of IS elements and the role they may play in bacterial genome plasticity.

scholarly journals Insertion-sequence-mediated mutations both promote and constrain evolvability during a long-term experiment with bacteria

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jessika Consuegra ◽  
Joël Gaffé ◽  
Richard E. Lenski ◽  
Thomas Hindré ◽  
Jeffrey E. Barrick ◽  
...  
Keyword(s):  
Insertion Sequence ◽  
Fold Increase ◽  
Genomic Evolution ◽  
Evolutionary Time ◽  
Is Elements ◽  
Beneficial Effects ◽  
Term Experiment ◽  
Long Term Experiment ◽  
Insertion Mutations

AbstractInsertion sequences (IS) are ubiquitous bacterial mobile genetic elements, and the mutations they cause can be deleterious, neutral, or beneficial. The long-term dynamics of IS elements and their effects on bacteria are poorly understood, including whether they are primarily genomic parasites or important drivers of adaptation by natural selection. Here, we investigate the dynamics of IS elements and their contribution to genomic evolution and fitness during a long-term experiment with Escherichia coli. IS elements account for ~35% of the mutations that reached high frequency through 50,000 generations in those populations that retained the ancestral point-mutation rate. In mutator populations, IS-mediated mutations are only half as frequent in absolute numbers. In one population, an exceptionally high ~8-fold increase in IS150 copy number is associated with the beneficial effects of early insertion mutations; however, this expansion later slowed down owing to reduced IS150 activity. This population also achieves the lowest fitness, suggesting that some avenues for further adaptation are precluded by the IS150-mediated mutations. More generally, across all populations, we find that higher IS activity becomes detrimental to adaptation over evolutionary time. Therefore, IS-mediated mutations can both promote and constrain evolvability.

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