In organello replication and viral affinity of linear, extrachromosomal DNA of the ascomycete Ascobolus immersus

1989 ◽  
Vol 218 (3) ◽  
pp. 523-530 ◽  
Author(s):  
F. Kempken ◽  
F. Meinhardt ◽  
K. Esser
Keyword(s):  
Extrachromosomal Dna ◽  
In Organello ◽  
Ascobolus Immersus

ИМПОРТ ДНК В МИТОХОНДРИИ РАСТЕНИЙ: КОМПЛЕКСНЫЙ ПОДХОД ДЛЯ ИЗУЧЕНИЯ in organello И in vivo

2019 ◽  
Vol 84 (7) ◽  
pp. 1036-1048
Author(s):  
Т.А. Тарасенко ◽  
В.И. Тарасенко ◽  
М.В. Кулинченко ◽  
Е.С. Клименко ◽  
Ю.М. Константинов
Keyword(s):  
In Organello

Extrachromosomal DNA: Redefining the pathogenesis of glioblastoma

2021 ◽  
Vol 1876 (1) ◽  
pp. 188551
Author(s):  
Anjali Shiras ◽  
Abir Mondal
Keyword(s):  
Extrachromosomal Dna

scholarly journals Ku80-deficient Cells Exhibit Excess Degradation of Extrachromosomal DNA

1996 ◽  
Vol 271 (24) ◽  
pp. 14405-14411 ◽  
Author(s):  
Feng Liang ◽  
Maria Jasin
Keyword(s):  
Extrachromosomal Dna

scholarly journals Extensive, Nonrandom Diversity of Excision Footprints Generated by Ds-Like Transposon Ascot-1Suggests New Parallels with V(D)J Recombination

1998 ◽  
Vol 18 (7) ◽  
pp. 4337-4346 ◽  
Author(s):  
Vincent Colot ◽  
Vicki Haedens ◽  
Jean-Luc Rossignol
Keyword(s):  
Extensive Study ◽  
Empty Site ◽  
Site Factors ◽  
Original Sequence ◽  
Ascobolus Immersus ◽  
High Degree ◽  
Hairpin Formation ◽  
Processing Steps ◽  
Color Gene

ABSTRACT Upon insertion, transposable elements can disrupt or alter gene function in various ways. Transposons moving through a cut-and-paste mechanism are in addition often mutagenic when excising because repair of the empty site seldom restores the original sequence. The characterization of numerous excision events in many eukaryotes indicates that transposon excision from a given site can generate a high degree of DNA sequence and phenotypic variation. Whether such variation is generated randomly remains largely to be determined. To this end, we have exploited a well-characterized system of genetic instability in the fungus Ascobolus immersus to perform an extensive study of excision events. We show that this system, which produces many phenotypically and genetically distinct derivatives, results from the excision of a novel Ds-like transposon,Ascot-1, from the spore color gene b2. A unique set of 48 molecularly distinct excision products were readily identified from a representative sample of excision derivatives. Products varied in their frequency of occurrence over 4 orders of magnitude, yet most showed small palindromic nucleotide additions. Based on these and other observations, compelling evidence was obtained for intermediate hairpin formation during the excision reaction and for strong biases in the subsequent processing steps at the empty site. Factors likely to be involved in these biases suggest new parallels between the excision reaction performed by transposons of thehAT family and V(D)J recombination. An evaluation of the contribution of small palindromic nucleotide additions produced by transposon excision to the spectrum of spontaneous mutations is also presented.

scholarly journals Absence of rDNA amplification in the uninucleolate oocyte of the cockroach Blattella germanica (Oorthoptera: Blattidae).

1976 ◽  
Vol 71 (1) ◽  
pp. 49-58 ◽  
Author(s):  
M D Cave
Keyword(s):  
Ribosomal Rna ◽  
General Pattern ◽  
Blattella Germanica ◽  
Nucleolar Organizer ◽  
Extrachromosomal Dna ◽  
Total Dna ◽  
Cockroach Blattella Germanica ◽  
Rdna Amplification ◽  
Large Nucleolus

Amplification of the genes coding for ribosomal RNA oocurs in the oocytes of a wide variety of organisms. In oocytes of various species of crickets (Orthoptera: Gryllidae) the amplified DNA is contained in a large extrachromosomal DNA body. Multiple nucleoli form about the periphery of the DNA body during the diplotene stage of meiosis I. In contrast to the general pattern of orthopteran oocytes, oocytes of the cockroach Blattella germanica demonstrate a single large nucleolus instead of many nucleoli. In order to determine whether the genes coding for rRNA are amplified in the oocytes of B. germanica, the relative amount of rDNA in oocytes was compared with the rDNA content of spermatocytes and somatic cells. An extrachromosomal DNA body similar to that present in crickets is not present in B. germanica. A satellite DNA band which contains nucleotide sequences complementary to rRNA accounts for approximately 3-5% of the total DNA in somatic and in male and female gametogenic tissues. Female cells contain approximately twice as much rDNA as do male cells. An XX-XO sex-determining mechanism is operative in B. germanica. In situ hybridization with rRNA indicates that the nucleolar organizer is located on one end of the X chromosome and that oocytes do not contain more than twice the amount of rDNA found in spermato cytes. The data indicate that rDNA is not amplified in the uninucleolate oocyte of B germanica.

scholarly journals Protein binding to a single termination-associated sequence in the mitochondrial DNA D-loop region.

1993 ◽  
Vol 13 (4) ◽  
pp. 2162-2171 ◽  
Author(s):  
C S Madsen ◽  
S C Ghivizzani ◽  
W W Hauswirth
Keyword(s):  
Mitochondrial Dna ◽  
Protein Binding ◽  
Loop Formation ◽  
Sequence Element ◽  
Conserved Sequence ◽  
Loop Region ◽  
In Organello ◽  
Close Proximity ◽  
D Loop

A methylation protection assay was used in a novel manner to demonstrate a specific bovine protein-mitochondrial DNA (mtDNA) interaction within the organelle (in organello). The protected domain, located near the D-loop 3' end, encompasses a conserved termination-associated sequence (TAS) element which is thought to be involved in the regulation of mtDNA synthesis. In vitro footprinting studies using a bovine mitochondrial extract and a series of deleted mtDNA templates identified a approximately 48-kDa protein which binds specifically to a single TAS element also protected within the mitochondrion. Because other TAS-like elements located in close proximity to the protected region did not footprint, protein binding appears to be highly sequence specific. The in organello and in vitro data, together, provide evidence that D-loop formation is likely to be mediated, at least in part, through a trans-acting factor binding to a conserved sequence element located 58 bp upstream of the D-loop 3' end.

Extrachromosomal DNA elements of plant pathogenic mycoplasmalike organisms

1991 ◽  
Vol 13 (1) ◽  
pp. 26-32 ◽  
Author(s):  
A.S. Denes ◽  
R.C. Sinha
Keyword(s):  
Extrachromosomal Dna ◽  
Dna Elements ◽  
Mycoplasmalike Organisms

scholarly journals Recombination within the Y locus in Ascobolus immersus

1967 ◽  
Vol 9 (2) ◽  
pp. 159-177 ◽  
Author(s):  
A. Kruszewska ◽  
W. Gajewski
Keyword(s):  
Opposite Direction ◽  
Negative Correlation ◽  
Linear Order ◽  
Great Majority ◽  
Wild Type Allele ◽  
Wild Type ◽  
Marker Effect ◽  
Dna Models ◽  
Ascobolus Immersus ◽  
Hybrid Dna

Mutants of the Y locus differed appreciably in their basic conversion frequencies (frequencies of conversion in one-point crosses) to wild type. The differences in the basic conversion frequencies in the opposite direction, i.e. from corresponding wild-type allele to mutant, were in general not pronounced. For some alleles frequencies of conversion in both directions were similar, but for the others they differed markedly. No evident correlation between the position of mutants on the map and their basic conversion frequencies was observed.In two-point crosses in repulsion, the great majority of recombinant octads were of conversion type. In these crosses symmetry or asymmetry of conversion depended mainly on similarity or differences in basic conversion frequencies of mutants crossed. In crosses between mutants from different clusters the recombination frequencies were near to the sums of their basic conversion frequencies. Such ‘mutant specificity’ makes it impossible to establish the linear order of mutants on the basis of recombination frequencies in two-point crosses.The results of two-point crosses in repulsion between mutants within clusters pointed to the influence of one allele on the frequency of conversion of another one. This ‘marker effect’ was also evident in some three-point crosses.The frequencies of simultaneous conversions in two-point crosses in coupling did not show negative correlation with the distances between the mutants involved.It seems that many of the data presented here are most easily explained by recently developed hybrid DNA models.

Nonrandom transition from asymmetrical to symmetrical hybrid DNA during meiotic recombination

Genome ◽  
1989 ◽  
Vol 32 (3) ◽  
pp. 414-419 ◽  
Author(s):  
Angelos Kalogeropoulos ◽  
Jean-Luc Rossignol
Keyword(s):  
Meiotic Recombination ◽  
Heteroduplex Dna ◽  
Dna Distribution ◽  
Left Part ◽  
Ascobolus Immersus ◽  
Two Phases ◽  
The Right ◽  
Hybrid Dna

During meiotic recombination, in the b2 gene of Ascobolus immersus hybrid DNA can be formed either on only one (asymmetrical hybrid DNA) or on both (symmetrical hybrid DNA) interacting chromatids. The two phases can be found in the same meiosis, involving the same two interacting chromatids with the symmetrical phase located on the right with regard to the asymmetrical one. We show that the transition from the asymmetrical to the symmetrical phase occurs in a defined region located within the left part of the gene, which is closer to the initiation region. Once formed, the symmetrical hybrid DNA phase seems always to extend to the rightmost mutation sites. This contrasts with asymmetrical hybrid DNA extension, which when it stays in asymmetrical form, may stop within the gene.Key words: Ascobolus immersus, heteroduplex DNA distribution.

The Landscape of Extrachromosomal DNA (ecDNA) in the Normal Hematopoiesis and Leukemia Evolution

2022 ◽  
Author(s):  
Tiansheng Zeng ◽  
Wenhui Huang ◽  
Longzhen Cui ◽  
Wenjuan Zhang ◽  
Qing Lin ◽  
...  
Keyword(s):  
Extrachromosomal Dna
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