scholarly journals Mutator-Like Elements with Multiple Long Terminal Inverted Repeats in Plants

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Ann A. Ferguson ◽  
Ning Jiang
Keyword(s):  
Transposable Elements ◽  
Binding Sites ◽  
Sequence Conservation ◽  
Inverted Repeats ◽  
Gene Fragment ◽  
Gene Sequences ◽  
Dna Transposons ◽  
Terminal Inverted Repeats ◽  
Multiple Copies ◽  
Successful Amplification

Mutator-like transposable elements (MULEs) are widespread in plants and the majority have long terminal inverted repeats (TIRs), which distinguish them from other DNA transposons. It is known that the long TIRs ofMutatorelements harbor transposase binding sites and promoters for transcription, indicating that the TIR sequence is critical for transposition and for expression of sequences between the TIRs. Here, we report the presence of MULEs with multiple TIRs mostly located in tandem. These elements are detected in the genomes of maize, tomato, rice, andArabidopsis. Some of these elements are present in multiple copies, suggesting their mobility. For those elements that have amplified, sequence conservation was observed for both of the tandem TIRs. For one MULE family carrying a gene fragment, the elements with tandem TIRs are more prevalent than their counterparts with a single TIR. The successful amplification of this particular MULE demonstrates that MULEs with tandem TIRs are functional in both transposition and duplication of gene sequences.

scholarly journals Identification of a regulatory transposon that controls the Mutator transposable element system in maize.

Genetics ◽  
1991 ◽  
Vol 129 (1) ◽  
pp. 261-270 ◽  
Author(s):  
P Chomet ◽  
D Lisch ◽  
K J Hardeman ◽  
V L Chandler ◽  
M Freeling
Keyword(s):  
Transposable Elements ◽  
Transposable Element ◽  
Restriction Fragment ◽  
Distinct Element ◽  
Single Locus ◽  
Inverted Repeats ◽  
Terminal Inverted Repeats ◽  
Mutator Activity ◽  
Element System ◽  
Multiple Copies

Abstract The Mutator system of maize consists of more than eight different classes of transposable elements each of which can be found in multiple copies. All Mu elements share the approximately 220-bp terminal inverted repeats, whereas each distinct element class is defined by its unique internal sequences. The regulation of instability of this system has been difficult to elucidate due to its multigenic inheritance. Here we present genetic experiments which demonstrate that there is a single locus, MuR1, which can regulate the transposition of Mu1 elements. We describe the cloning of members of a novel class of Mu elements, MuR, and demonstrate that a member of the class is the regulator of Mutator activity, MuR1. This conclusion is based on several criteria: MuR1 activity and a MuR-homologous restriction fragment cosegregate; when MuR1 undergoes a duplicative transposition, an additional MuR restriction fragment is observed, and MuR1 activity and the cosegregating MuR fragment are simultaneously lost within clonal somatic sectors. In addition, the MuR element hybridizes to transcripts in plants with Mutator activity. Our genetic experiments demonstrate that the MuR1 transposon is necessary to specify Mutator activity in our lines.

scholarly journals Characterization of a Class II Defective Transposon Carrying Two Haloacetate Dehalogenase Genes from Delftia acidovorans Plasmid pUO1

2002 ◽  
Vol 68 (5) ◽  
pp. 2307-2315 ◽  
Author(s):  
Masahiro Sota ◽  
Masahiro Endo ◽  
Keiji Nitta ◽  
Haruhiko Kawasaki ◽  
Masataka Tsuda
Keyword(s):  
Transposable Elements ◽  
Class Ii ◽  
Class I ◽  
Inverted Repeats ◽  
High Homology ◽  
Terminal Inverted Repeats ◽  
Delftia Acidovorans

ABSTRACT The two haloacetate dehalogenase genes, dehH1 and dehH2, on the 65-kb plasmid pUO1 from Delftia acidovorans strain B were found to be located on transposable elements. The dehH2 gene was carried on an 8.9-kb class I composite transposon (TnHad1) that was flanked by two directly repeated copies of IS1071, IS1071L and IS1071R. The dehH1 gene was also flanked by IS1071L and a truncated version of IS1071 (IS1071N). TnHad1, dehH1, and IS1071N were located on a 15.6-kb class II transposon (TnHad2) whose terminal inverted repeats and res site showed high homology with those of the Tn21-related transposons. TnHad2 was defective in transposition because of its lacking the transposase and resolvase genes. TnHad2 could transpose when the Tn21-encoded transposase and resolvase were supplied in trans. These results demonstrated that Tn Had2 is a defective Tn21-related transposon carrying another class I catabolic transposon.

scholarly journals Cloning of the Mutator transposable element MuA2, a putative regulator of somatic mutability of the a1-Mum2 allele in maize.

Genetics ◽  
1991 ◽  
Vol 129 (3) ◽  
pp. 845-854 ◽  
Author(s):  
M M Qin ◽  
D S Robertson ◽  
A H Ellingboe
Keyword(s):  
Transposable Elements ◽  
Transposable Element ◽  
Copy Number ◽  
Inverted Repeats ◽  
Terminal Inverted Repeats ◽  
Somatic Instability ◽  
Mutator Activity ◽  
Element System ◽  
Lines Of Evidence

Abstract The identification of the autonomous or transposase-encoding element of the Mutator (Mu) transposable element system of maize is necessary to the characterization of the system. We reported previously that a transcript homologous to the internal region of the MuA element is associated with activity of the Mutator system. We describe here the cloning of another Mu element, designated MuA2, that cosegregates with Mutator activity as assayed by somatic instability of the a1-Mum2 allele. The MuA2 element has features typical of the transposable elements of the Mutator family, including the 210-bp terminal inverted repeats. Several lines of evidence suggest that MuA2 is an autonomous or transposase-encoding element of the Mu family: (1) MuA2 cosegregates with a genetically defined element that regulates somatic mutability of the a1-Mum2 allele; (2) MuA2 is hypomethylated while most other MuA2-hybridizing sequences in the genome are extensively methylated; (3) the increase of the copy number of MuA2 is concomitant with the increase of regulator elements; (4) MuA2-like elements are found in Mutator lines but not in non-Mutator inbreds. We propose that autonomous or transposase-encoding elements of the Mu family may be structurally conserved and MuA2-like.

scholarly journals Multiple Roles for TnpI Recombinase in Regulation of Tn5401 Transposition in Bacillus thuringiensis

1999 ◽  
Vol 181 (20) ◽  
pp. 6271-6277 ◽  
Author(s):  
James A. Baum ◽  
Amy Jelen Gilmer ◽  
Anne-Marie Light Mettus
Keyword(s):  
Catalytic Activity ◽  
Bacillus Thuringiensis ◽  
Binding Sites ◽  
Negative Regulation ◽  
Multiple Roles ◽  
Inverted Repeats ◽  
Positive Bacterium ◽  
Site Specific ◽  
Terminal Inverted Repeats ◽  
A Site

ABSTRACT Tn5401 is a class II transposable element derived from the gram-positive bacterium Bacillus thuringiensis. The 4,837-bp transposon encodes a Tn3-like transposase (TnpA) and an integrase-like recombinase (TnpI) and is notable for its unusually long 53-bp terminal inverted repeats (TIRs). ThetnpA and tnpI genes are transcribed from a common promoter, designated PR, that is subject to negative regulation by TnpI. The TIRs of Tn5401 each contain a 38-bp sequence that can be aligned with the 38- to 40-bp TIR sequences of Tn3-like transposons and an adjacent 12-bp sequence that binds TnpI. This unique juxtaposition of TnpA and TnpI binding sites suggests that TnpI may regulate the binding or catalytic activity of TnpA. The results of the present study indicate that TnpI, in addition to functioning as a site-specific recombinase and as a transcriptional repressor, is required for TnpA binding to the TIRs of Tn5401.

scholarly journals Molecular characterization of mariner-like elements in Bruchus pisorum and Bruchus rufimanus (Coleoptera: Bruchidae)

2017 ◽  
Vol 69 (2) ◽  
pp. 353-360 ◽  
Author(s):  
Salma Djebbi ◽  
Amara Ben ◽  
Hanem Makni ◽  
Mohamed Makni ◽  
Maha Mezghani-Khemakhem
Keyword(s):  
Phylogenetic Analysis ◽  
Amino Acid ◽  
Transposable Elements ◽  
Inverted Repeats ◽  
Terminal Inverted Repeats ◽  
Transfer Genes ◽  
Recent Origin ◽  
Bruchus Pisorum ◽  
Respective Host

Mariner-like elements (MLEs) are Class-II transposons that are widely present in diverse organisms and encode a D,D34D transposase motif. MLE sequences from two coleopteran species, Bruchuspisorum and B. rufimanus were obtained using the terminal-inverted repeats (TIRs) of mariner elements belonging to the mauritiana subfamily as primer. The characterized elements were between 1073 and 1302 bp in length and are likely to be inactive, based on the presence of multiple stop codons and/or frameshifts. A single consensus of MLE was detected in B. pisorum and was named Bpmar1. This element exhibited several conserved amino acid blocks as well as the specific D,D(34)D signature. As for B. rufimanus, two MLE consensuses, designated Brmar1 and Brmar2, were isolated, both containing deletions overlapping the internal region of the transposase. Structural and phylogenetic analysis of these sequences suggested a relatively recent origin of Bpmar1 versus a more ancient invasion of Brmar1 and Brmar2 in their respective host genomes. Given that MLEs are potential mediators of insect resistance and have been used as vectors to transfer genes into host genomes, the MLEs characterized in this study will have valuable implications for selecting appropriate transposable elements in transgenesis.

scholarly journals Sequence motifs recognized by the casposon integrase of Aciduliprofundum boonei

2019 ◽  
Vol 47 (12) ◽  
pp. 6386-6395 ◽  
Author(s):  
Pierre Béguin ◽  
Yankel Chekli ◽  
Guennadi Sezonov ◽  
Patrick Forterre ◽  
Mart Krupovic
Keyword(s):  
Integration Site ◽  
Target Site ◽  
Inverted Repeats ◽  
Leader Region ◽  
Sequence Motifs ◽  
Dna Transposons ◽  
Terminal Inverted Repeats ◽  
Thermophilic Archaeon ◽  
Evolutionary Connection

Abstract Casposons are a group of bacterial and archaeal DNA transposons encoding a specific integrase, termed casposase, which is homologous to the Cas1 enzyme responsible for the integration of new spacers into CRISPR loci. Here, we characterized the sequence motifs recognized by the casposase from a thermophilic archaeon Aciduliprofundum boonei. We identified a stretch of residues, located in the leader region upstream of the actual integration site, whose deletion or mutagenesis impaired the concerted integration reaction. However, deletions of two-thirds of the target site were fully functional. Various single-stranded 6-FAM-labelled oligonucleotides derived from casposon terminal inverted repeats were as efficiently incorporated as duplexes into the target site. This result suggests that, as in the case of spacer insertion by the CRISPR Cas1–Cas2 integrase, casposon integration involves splaying of the casposon termini, with single-stranded ends being the actual substrates. The sequence critical for incorporation was limited to the five terminal residues derived from the 3′ end of the casposon. Furthermore, we characterize the casposase from Nitrosopumilus koreensis, a marine member of the phylum Thaumarchaeota, and show that it shares similar properties with the A. boonei enzyme, despite belonging to a different family. These findings further reinforce the mechanistic similarities and evolutionary connection between the casposons and the adaptation module of the CRISPR–Cas systems.

scholarly journals Composite transposable elements in the Xenopus laevis genome.

1989 ◽  
Vol 9 (7) ◽  
pp. 3018-3027 ◽  
Author(s):  
J E Garrett ◽  
D S Knutzon ◽  
D Carroll
Keyword(s):  
Xenopus Laevis ◽  
Transposable Elements ◽  
Repetitive Sequences ◽  
Open Reading Frames ◽  
The Other ◽  
Inverted Repeats ◽  
Terminal Inverted Repeats ◽  
Gag Proteins ◽  
High Degree ◽  
Reading Frames

Members of two related families of transposable elements, Tx1 and Tx2, were isolated from the genome of Xenopus laevis and characterized. In both families, two versions of the elements were found. The smaller version in each family (Tx1d and Tx2d) consisted largely of two types of 400-base-pair tandem internal repeats. These elements had discrete ends and short inverted terminal repeats characteristic of mobile DNAs that are presumed to move via DNA intermediates, e.g., Drosophila P and maize Ac elements. The longer versions (Tx1c and Tx2c) differed from Tx1d and Tx2d by the presence of a 6.9-kilobase-pair internal segment that included two long open reading frames (ORFs). ORF1 had one cysteine-plus-histidine-rich sequence of the type found in retroviral gag proteins. ORF2 showed more substantial homology to retroviral pol genes and particularly to the analogs of pol found in a subclass of mobile DNAs that are supposed retrotransposons, such as mammalian long interspersed repetitive sequences, Drosophila I factors, silkworm R1 elements, and trypanosome Ingi elements. Thus, the Tx1 elements present a paradox by exhibiting features of two classes of mobile DNAs that are thought to have very different modes of transposition. Two possible resolutions are considered: (i) the composite versions are actually made up of two independent elements, one of the retrotransposon class, which has a high degree of specificity for insertion into a target within the other, P-like element; and (ii) the composite elements are intact, autonomous mobile DNAs, in which the pol-like gene product collaborates with the terminal inverted repeats to cause transposition of the entire unit.

scholarly journals Regulation of Transposable Element Activities during Plant Development

1992 ◽  
Author(s):  
Avraham A. Levy ◽  
Virginia Walbot
Keyword(s):  
Plant Development ◽  
Binding Sites ◽  
Antisense Rna ◽  
Tissue Specificity ◽  
Housekeeping Genes ◽  
S Phase ◽  
Inverted Repeats ◽  
Tobacco Plants ◽  
Terminal Inverted Repeats ◽  
Heterologous System

We have studied the regulation of the maize Ac and MuDR transposable elements activities during plant development. Ac was studied in an heterologous system (transgenic tobacco plants and cell suspensions) while MuDR was studied in the native maize background. The focus of this study was on the transcriptional regulation of Ac and MuDR. For Ac, the major achievements were to show that 1-It is autoregulated in a way that the Ac-encoded transposase can repress the activity of its own promoter; 2-It is expressed at low basal level in all the plant organs that were studied, and its activity is stronger in dividing tissues -- a behaviour reminiscent of housekeeping genes; 3- the activity of Ac promoter is cell cycle regulated -- induced at early S-phase and increasing until mitosis; 4- host factor binding sites were identified at both extremities of Ac and may be important for transposition. For MuDR, It was shown that it encodes two genes, mudrA and mudrB, convergently transcribed from near-identical promoters in the terminal inverted repeats. Distinct 5' start sites, alternative splicing, production of antisense RNA and tissue specificity were all shown to be involved in the regulation of MuDR.

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