Characterizing the topology of kinetoplast DNA using random knotting

2020 ◽  
pp. 17-39
Author(s):  
P. Liu ◽  
R. Polischuk ◽  
Y. Diao ◽  
J. Arsuaga
Keyword(s):  
Kinetoplast Dna

Evaluation of the dark field method for large association of spread DNA

1978 ◽  
Vol 36 (2) ◽  
pp. 190-191
Author(s):  
Douglas C. Barker
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Mitochondrial Dna ◽  
Extraction Method ◽  
Field Method ◽  
Dark Field ◽  
Kinetoplast Dna ◽  
Field Electron ◽  
Field Electron Microscopy ◽  
Dark Field Electron

A number of satisfactory methods are available for the electron microscopy of nicleic acids. These methods concentrated on fragments of nuclear, viral and mitochondrial DNA less than 50 megadaltons, on denaturation and heteroduplex mapping (Davies et al 1971) or on the interaction between proteins and DNA (Brack and Delain 1975). Less attention has been paid to the experimental criteria necessary for spreading and visualisation by dark field electron microscopy of large intact issociations of DNA. This communication will report on those criteria in relation to the ultrastructure of the (approx. 1 x 10-14g) DNA component of the kinetoplast from Trypanosomes. An extraction method has been developed to eliminate native endonucleases and nuclear contamination and to isolate the kinetoplast DNA (KDNA) as a compact network of high molecular weight. In collaboration with Dr. Ch. Brack (Basel [nstitute of Immunology), we studied the conditions necessary to prepare this KDNA Tor dark field electron microscopy using the microdrop spreading technique.

scholarly journals A highly bent fragment of Crithidia fasciculata kinetoplast DNA.

1986 ◽  
Vol 261 (24) ◽  
pp. 11302-11309 ◽  
Author(s):  
P A Kitchin ◽  
V A Klein ◽  
K A Ryan ◽  
K L Gann ◽  
C A Rauch ◽  
...  
Keyword(s):  
Kinetoplast Dna ◽  
Crithidia Fasciculata

scholarly journals The Double-Edged Sword in Pathogenic Trypanosomatids: The Pivotal Role of Mitochondria in Oxidative Stress and Bioenergetics

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Rubem Figueiredo Sadok Menna-Barreto ◽  
Solange Lisboa de Castro
Keyword(s):  
Trypanosoma Brucei ◽  
Cell Signalling ◽  
Oxygen Species ◽  
Kinetoplast Dna ◽  
Excellent Candidate ◽  
Causative Agents ◽  
Parasite Biology ◽  
Oxidative Regulation ◽  
Single Mitochondrion

The pathogenic trypanosomatidsTrypanosoma brucei,Trypanosoma cruzi, andLeishmaniaspp. are the causative agents of African trypanosomiasis, Chagas disease, and leishmaniasis, respectively. These diseases are considered to be neglected tropical illnesses that persist under conditions of poverty and are concentrated in impoverished populations in the developing world. Novel efficient and nontoxic drugs are urgently needed as substitutes for the currently limited chemotherapy. Trypanosomatids display a single mitochondrion with several peculiar features, such as the presence of different energetic and antioxidant enzymes and a specific arrangement of mitochondrial DNA (kinetoplast DNA). Due to mitochondrial differences between mammals and trypanosomatids, this organelle is an excellent candidate for drug intervention. Additionally, during trypanosomatids’ life cycle, the shape and functional plasticity of their single mitochondrion undergo profound alterations, reflecting adaptation to different environments. In an uncoupling situation, the organelle produces high amounts of reactive oxygen species. However, these species role in parasite biology is still controversial, involving parasite death, cell signalling, or even proliferation. Novel perspectives on trypanosomatid-targeting chemotherapy could be developed based on better comprehension of mitochondrial oxidative regulation processes.

Maxi-circles in the kinetoplast DNA of Trypanosoma mega

1977 ◽  
Vol 110 (1) ◽  
pp. 167-173 ◽  
Author(s):  
Piet Borst ◽  
Francesca Fase-Fowler ◽  
Maurice Steinert ◽  
Suzanne Van Assel
Keyword(s):  
Kinetoplast Dna

The rotational dynamics of kinetoplast DNA replication

2007 ◽  
Vol 64 (3) ◽  
pp. 676-690 ◽  
Author(s):  
Yanan Liu ◽  
Paul T. Englund
Keyword(s):  
Dna Replication ◽  
Rotational Dynamics ◽  
Kinetoplast Dna

scholarly journals KINETOPLAST DEOXYRIBONUCLEIC ACID OF THE HEMOFLAGELLATE TRYPANOSOMA LEWISI

1970 ◽  
Vol 47 (3) ◽  
pp. 689-702 ◽  
Author(s):  
Hartmut C. Renger ◽  
David R. Wolstenholme
Keyword(s):  
Electron Microscope ◽  
Ethidium Bromide ◽  
Thermal Denaturation ◽  
Deoxyribonucleic Acid ◽  
Cesium Chloride ◽  
Kinetoplast Dna ◽  
Microscope Examination ◽  
Main Band ◽  
Trypanosoma Lewisi ◽  
High Degree

Cesium chloride centrifugation of DNA extracted from cells of blood strain Trypanosoma lewisi revealed a main band, ρ = 1.707, a light satellite, ρ = 1.699, and a heavy satellite, ρ = 1.721. Culture strain T. lewisi DNA comprised only a main band, ρ = 1.711, and a light satellite, ρ = 1.699. DNA isolated from DNase-treated kinetoplast fractions of both the blood and culture strains consisted of only the light satellite DNA. Electron microscope examination of rotary shadowed preparations of lysates revealed that DNA from kinetoplast fractions was mainly in the form of single 0.4 µ circular molecules and large masses of 0.4 µ interlocked circles with which longer, often noncircular molecules were associated. The 0.4 µ circular molecules were mainly in the covalently closed form: they showed a high degree of resistance to thermal denaturation which was lost following sonication; and they banded at a greater density than linear DNA in cesium chloride-ethidium bromide gradients. Interpretation of the large masses of DNA as comprising interlocked covalently closed 0.4 µ circles was supported by the findings that they banded with single circular molecules in cesium chloride-ethidium bromide gradients, and following breakage of some circles by mild sonication, they disappeared and were replaced by molecules made up of low numbers of apparently interlocked 0.4 µ circles. When culture strain cells were grown in the presence of either ethidium bromide or acriflavin, there was a loss of stainable kinetoplast DNA in cytological preparations. There was a parallel loss of light satellite and of circular molecules from DNA extracted from these cells.

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