Search results for "Nuclear DNA"

Is “I-DNA” derived from Nuclear DNA ?

1970

On the basis of double radioactive labelling and buoyant density studies, it is concluded that “I-DNA” is not a separate entity from nuclear DNA but may be an artefact derived from it.

Hybridization within the Rana ridibunda Complex of North Africa

1980

Abstract Cellogel electrophoretic study of the plasma protein pattern, especially the albumin fractions, and microdensitometric determination of erythrocyte nuclear DNA amount in 25 frogs of the Rana ridibunda complex from different localities in Morocco and Algeria allows the conclusion that two different forms of this complex are hybridizing in North Africa, as it is found in the Rana esculenta complex in Europe or in the East Asian green frogs. These forms can be identified by their albumin alleles, but not yet by their morphology. They produce mainly triploid hybrids.

Mitochondrial DNA sequences are present inside nuclear DNA in rat tissues and increase with age

2009

Abstract Mitochondrial DNA (mtDNA) mutations increase with age. However, the number of cells with predominantly mutated mtDNA is small in old animals. Here a new hypothesis is proposed: mtDNA fragments may insert into nuclear DNA contributing to aging and related diseases by alterations in the nucleus. Real-time PCR quantification shows that sequences of cytochrome oxidase III and 16S rRNA from mtDNA are present in highly purified nuclei from liver and brain in young and old rats. The sequences of these insertions revealed that they contain single nucleotide polymorphisms identical to those present in mtDNA of the same animal. Interestingly, the amount of mitochondrial sequences in nuclear …

Cytogenetics of the land snails Cantareus aspersus and C. mazzullii (Mollusca: Gastropoda: Pulmonata).

2004

A cytogenetic study was carried out on the chromosomes and nuclear DNA contents of the land snails Cantareus aspersus and C. mazzullii (Gastropoda: Pulmonata). Chromosomes were studied using Giemsa staining, banding methods and fluorescent in situ hybridization (FISH) with three repetitive DNA probes [18S rDNA, (GATA)n and (TTAGGG)n]. Results were very similar in the two species both showing (1) 54 bi-armed chromosomes [submetacentrics (SM) C metacentrics (M) C subtelocentrics (ST)]; (2) 10 terminal NORs after sequential application of rDNA FISH and silver staining; (3) uniform DNA fluorescence with CMA3 and DAPI staining and (4) genomic composition considerably enriched both in highly- and…

Molecular Evolution and the Phylogenetic Relationships of the African Toad, Bufo danielae PERRET, 1977 (Salientia : Bufonidae)

1980

Abstract Phylogenetic relationships of the African toad Bufo danielae are investigated using a variety of biochemical approaches. Nuclear DNA content was assayed and compared to representatives of three species groups of African Bufo. Cellogel electrophoresis of plasma proteins was performed and patterns of B. danielae compared with those of representatives of the African B. regularis species complex. Finally microcomplement fixation analyses of albumin relationships of B. danielae and African Bufo were carried out. The strengths of the varied approaches for phylogenetic analysis are discussed. B. danielae appears most closely related to B. maculatus and B. pusillus, it being some 5-6 mill…

Mitochondrial DNA Replacement Techniques to Prevent Human Mitochondrial Diseases.

2021

Background: Mitochondrial DNA (mtDNA) diseases are a group of maternally inherited genetic disorders caused by a lack of energy production. Currently, mtDNA diseases have a poor prognosis and no known cure. The chance to have unaffected offspring with a genetic link is important for the affected families, and mitochondrial replacement techniques (MRTs) allow them to do so. MRTs consist of transferring the nuclear DNA from an oocyte with pathogenic mtDNA to an enucleated donor oocyte without pathogenic mtDNA. This paper aims to determine the efficacy, associated risks, and main ethical and legal issues related to MRTs. Methods: A bibliographic review was performed on the MEDLINE and Web of S…

The basal levels of 8-oxoG and other oxidative modifications in intact mitochondrial DNA are low even in repair-deficient (Ogg1(-/-)/Csb(-/-)) mice.

2007

Abstract Mitochondrial DNA (mtDNA) is assumed to be highly prone to damage by reactive oxygen species (ROS) because of its location in close proximity to the mitochondrial electron transport chain. Accordingly, mitochondrial oxidative DNA damage has been hypothesized to be responsible for various neurological diseases, ageing and cancer. Since 7,8-dihydro-8-oxoguanine (8-oxoG), one of the most frequent oxidative base modifications, is removed from the mitochondrial genome by the glycosylase OGG1, the basal levels of this lesion are expected to be highly elevated in Ogg1−/− mice. To investigate this hypothesis, we have used a mtDNA relaxation assay in combination with various repair enzymes …

Effects of the modulation of epoxide hydrolase activity on the binding of benzo[a]pyrene metabolites to DNA in the intact nuclei.

1983

Phylogenetic evidence for hybrid origins of asexual lineages in an aphid species

2003

International audience; Understanding the mode of origin of asexuality is central to ongoing debates concerning the evolution and maintenance of sexual reproduction in eukaryotes. This is because it has profound consequences for patterns of genetic diversity and ecological adaptability of asexual lineages, hence on the outcome of competition with sexual relatives both in short and longer terms. Among the possible routes to asexuality, hybridization is a very common mechanism in animals and plants. Aphids present frequent transitions from their ancestral reproductive mode (cyclical parthenogenesis) to permanent asexuality, but the mode of origin of asexual lineages is generally not known bec…

Generation of homozygosity and genome fixation in pea (Pisum sativum L.)

2013

Pea cultivars are nearly homozygous and thus homogeneous when they are released. The traditional method of selfing is slow and inefficient, taking up to ten generations of inbreeding following a cross to achieve a high level of homozygosity. Current single-seed-descent (SSD) methodologies enable a maximum of three generations per year to be developed in pea. Doubled haploidy and an in vitro based modified SSD technology have been utilised in many important crops for the rapid achievement of homozygosity, and thus acceleration of the breeding process. In pea, due to the lack of robust protocols, none of these technologies is routinely used in a breeding program. The aim of this study was to …