scholarly journals The Complete Mitochondrial DNA of Trypanosoma cruzi: Maxicircles and Minicircles

2021 ◽  
Vol 11 ◽  
Author(s):  
Francisco Callejas-Hernández ◽  
Alfonso Herreros-Cabello ◽  
Javier del Moral-Salmoral ◽  
Manuel Fresno ◽  
Núria Gironès
Keyword(s):  
Mitochondrial Dna ◽  
Trypanosoma Cruzi ◽  
Present Species ◽  
Consensus Sequences ◽  
Conserved Sequence ◽  
Conserved Regions ◽  
Sequencing Technologies ◽  
Hypervariable Regions ◽  
Mitochondrial Dnas ◽  
Species Specific

The mitochondrial DNA of Trypanosomatids, known as the kinetoplast DNA or kDNA or mtDNA, consists of a few maxicircles and thousands of minicircles concatenated together into a huge complex network. These structures present species-specific sizes, from 20 to 40 Kb in maxicircles and from 0.5 to 10 Kb in minicircles. Maxicircles are equivalent to other eukaryotic mitochondrial DNAs, while minicircles contain coding guide RNAs involved in U-insertion/deletion editing processes exclusive of Trypanosomatids that produce the maturation of the maxicircle-encoded transcripts. The knowledge about this mitochondrial genome is especially relevant since the expression of nuclear and mitochondrial genes involved in oxidative phosphorylation must be coordinated. In Trypanosoma cruzi (T. cruzi), the mtDNA has a dual relevance; the production of energy, and its use as a phylogenetic marker due to its high conservation among strains. Therefore, this study aimed to assemble, annotate, and analyze the complete repertoire of maxicircle and minicircle sequences of different T. cruzi strains by using DNA sequencing. We assembled and annotated the complete maxicircle sequence of the Y and Bug2148 strains. For Bug2148, our results confirm that the maxicircle sequence is the longest assembled to date, and is composed of 21 genes, most of them conserved among Trypanosomatid species. In agreement with previous results, T. cruzi minicircles show a conserved structure around 1.4 Kb, with four highly conserved regions and other four hypervariable regions interspersed between them. However, our results suggest that the parasite minicircles display several sizes and numbers of conserved and hypervariable regions, contrary to those previous studies. Besides, this heterogeneity is also reflected in the three conserved sequence blocks of the conserved regions that play a key role in the minicircle replication. Our results using sequencing technologies of second and third-generation indicate that the different consensus sequences of the maxicircles and minicircles seem to be more complex than previously described indicating at least four different groups in T. cruzi minicircles.

Nuclear gene products that function in mitochondrial DNA replication

1987 ◽  
Vol 317 (1187) ◽  
pp. 473-482 ◽  
Keyword(s):  
Mitochondrial Dna ◽  
Dna Synthesis ◽  
Nuclear Gene ◽  
Gene Products ◽  
Sequence Element ◽  
Dna Primase ◽  
Conserved Sequence ◽  
Initiation Of Replication ◽  
Mitochondrial Dnas ◽  
D Loop

Mammalian mitochondrial DNAs replicate unidirectionally from two distinct strand-specific origins. A round of replication begins at the heavy-strand origin (the D-loop) where transcripts from an upstream promoter serve as the primers for DNA synthesis. The transition from RNA to DNA synthesis occurs within short, conserved nucleotide sequence blocks and is mediated by specific endonucleolytic cleavage of the primary transcript. An enzymic component involved in the generation of primer RNA in mouse mitochondria has been identified. It is a sequence-specific endoribonuclease that cleaves single-stranded RNA substrate precisely at one of the transition sites. The other origin, that for light-strand synthesis, is located well apart on the genome and functions only when in a single-stranded template form. This origin has a defined secondary structure that is the most highly conserved sequence element in mammalian mitochondrial DNAs. Initiation of replication at this origin is by the action of a mitochondrial DNA primase, which is capable of synthesizing a short stretch of ribonucleotides before switching to DNA synthesis. Mitochondrial DNA primase appears to have an associated RNA species and the evidence to date suggests that components of both the D-loop endoribonuclease and the DNA primase are nuclear gene products.

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.

Assignment of two mitochondrially synthesized polypeptides to human mitochondrial DNA and their use in the study of intracellular mitochondrial interaction

1982 ◽  
Vol 2 (1) ◽  
pp. 30-41
Author(s):  
N A Oliver ◽  
D C Wallace
Keyword(s):  
Mitochondrial Dna ◽  
Restriction Site ◽  
Mitochondrial Protein ◽  
Mitochondrial Protein Synthesis ◽  
Human Mitochondrial Dna ◽  
Ht1080 Cells ◽  
Mitochondrial Dnas ◽  
A Cell ◽  
Dna Restriction ◽  
Restriction Site Polymorphisms

Two mitochondrially synthesized marker polypeptides, MV-1 and MV-2, were found in human HeLa and HT1080 cells. These were assigned to the mitochondrial DNA in HeLa-HT1080 cybrids and hybrids by demonstrating their linkage to cytoplasmic genetic markers. These markers include mitochondrial DNA restriction site polymorphisms and resistance to chloramphenicol, an inhibitor of mitochondrial protein synthesis. In the absence of chloramphenicol, the expression of MV-1 and MV-2 in cybrids and hybrids was found to be directly proportional to the ratio of the parental mitochondrial DNAs. In the presence of chloramphenicol, the marker polypeptide linked to the chloramphenicol-sensitive mitochondrial DNA continued to be expressed. This demonstrated that resistant and sensitive mitochondrial DNAs can cooperate within a cell for gene expression and that the CAP-resistant allele was dominant or codominant to sensitive. Such cooperation suggests that mitochondrial DNAs can be exchanged between mitochondria.

Quantitative Detection of Species-Specific DNA in Feedstuffs and Fish Meals

2005 ◽  
Vol 68 (6) ◽  
pp. 1217-1221 ◽  
Author(s):  
PAVEL KRCMAR ◽  
EVA RENCOVA
Keyword(s):  
Mitochondrial Dna ◽  
Real Time ◽  
Dna Sequences ◽  
Real Time Pcr ◽  
Single Species ◽  
Absolute Quantification ◽  
Quantitative Detection ◽  
Vertebrate Species ◽  
Target Species ◽  
Species Specific

A sensitive and rapid method for the quantitative detection of bovine-, ovine-, swine-, and chicken-specific mitochondrial DNA sequences based on real-time PCR has been developed. The specificity of the primers and probes for real-time PCR has been tested using DNA samples of other vertebrate species that may also be present in rendered products. The quantitative detection was performed with dual-labeled probes (TaqMan) using absolute quantification with external standards of single species meat-and-bone meals. This method facilitates the detection of 0.01% of the target species–derived material in concentrate feed mixtures and fish meals.

scholarly journals Global sequence characterization of rice centromeric satellite based on oligomer frequency analysis in large-scale sequencing data

2010 ◽  
Vol 26 (17) ◽  
pp. 2101-2108 ◽  
Author(s):  
Jiří Macas ◽  
Pavel Neumann ◽  
Petr Novák ◽  
Jiming Jiang
Keyword(s):  
Large Scale ◽  
Rice Genome ◽  
Supplementary Information ◽  
Sequencing Data ◽  
Satellite Repeat ◽  
Frequency Spectra ◽  
Consensus Sequences ◽  
Chip Sequencing ◽  
Conserved Sequence ◽  
Centromeric Satellite

Abstract Motivation: Satellite DNA makes up significant portion of many eukaryotic genomes, yet it is relatively poorly characterized even in extensively sequenced species. This is, in part, due to methodological limitations of traditional methods of satellite repeat analysis, which are based on multiple alignments of monomer sequences. Therefore, we employed an alternative, alignment-free, approach utilizing k-mer frequency statistics, which is in principle more suitable for analyzing large sets of satellite repeat data, including sequence reads from next generation sequencing technologies. Results: k-mer frequency spectra were determined for two sets of rice centromeric satellite CentO sequences, including 454 reads from ChIP-sequencing of CENH3-bound DNA (7.6 Mb) and the whole genome Sanger sequencing reads (5.8 Mb). k-mer frequencies were used to identify the most conserved sequence regions and to reconstruct consensus sequences of complete monomers. Reconstructed consensus sequences as well as the assessment of overall divergence of k-mer spectra revealed high similarity of the two datasets, suggesting that CentO sequences associated with functional centromeres (CENH3-bound) do not significantly differ from the total population of CentO, which includes both centromeric and pericentromeric repeat arrays. On the other hand, considerable differences were revealed when these methods were used for comparison of CentO populations between individual chromosomes of the rice genome assembly, demonstrating preferential sequence homogenization of the clusters within the same chromosome. k-mer frequencies were also successfully used to identify and characterize smRNAs derived from CentO repeats. Contact: [email protected] Supplementary information: Supplementary data are available at Bioinformatics online.

Mitochondrial behavior during nuclear and mitochondrial DNA repair in Trypanosoma cruzi epimastigotes

2020 ◽  
Vol 219 ◽  
pp. 108016
Author(s):  
Tamires Marco Antônio Salgado Martins ◽  
Eduardo de Figueiredo Peloso ◽  
Héllida Marina Costa-Silva ◽  
Matheus Andrade Rajão ◽  
Bennet Van Houten ◽  
...  
Keyword(s):  
Dna Repair ◽  
Mitochondrial Dna ◽  
Trypanosoma Cruzi ◽  
Mitochondrial Dna Repair

Cloth-Based Hybridization Array System for Expanded Identification of the Animal Species Origin of Derived Materials in Feeds

2007 ◽  
Vol 70 (12) ◽  
pp. 2900-2905 ◽  
Author(s):  
JOHANNA MURPHY ◽  
JENNIFER ARMOUR ◽  
BURTON W. BLAIS
Keyword(s):  
Mitochondrial Dna ◽  
Dna Sequences ◽  
Microscopic Examination ◽  
Animal Species ◽  
Specific Detection ◽  
Animal Feeds ◽  
Species Origin ◽  
Pcr Products ◽  
Species Specific ◽  
Immunoenzymatic Assay

A cloth-based hybridization array system (CHAS) previously developed for the detection of animal species for which prohibited materials have been specified (cattle, sheep, goat, elk, and deer) has been expanded to include the detection of animal species for which there are no prohibitions (pig and horse) in Canadian and American animal feeds. Animal species were identified by amplification of mitochondrial DNA sequences by PCR and subsequent hybridization of the amplicons with an array of species-specific oligonucleotide capture probes immobilized on a polyester cloth support, followed by an immunoenzymatic assay of the bound PCR products. The CHAS permitted sensitive and specific detection of meat meals from different animal species blended in a grain-based feed and should provide a useful adjunct to microscopic examination for the identification of prohibited materials in animal feeds.

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