Effects of overexpression of mitochondrial transcription factor A on lifespan and oxidative stress response in Drosophila melanogaster.

Mitochondrial transcription factor A (TFAM) plays a role in the maintenance of mitochondrial DNA (mtDNA) by packaging mtDNA, forming the mitochondrial nucleoid. There have been many reports about a function of TFAM at the cellular level, but only a few studies have been done in individual organisms. Here we examined the effects of TFAM on the Drosophila lifespan and oxidative stress response, by overexpressing TFAM using the GAL4/UAS system.

Comparative proteomic analyses of macular and peripheral retina of cynomolgus monkeys (Macaca fascicularis).

The central region of the primate retina is called the macula. The fovea is located at the center of the macula, where the photoreceptors are concentrated to create a neural network adapted for high visual acuity. Damage to the fovea, e.

Analysis of paternal transmission of mitochondrial DNA in Drosophila.

It has previously been shown that paternal mitochondrial DNA (mtDNA) can be detected in later generations in Drosophila. To further analyze the paternal transmission of mtDNA, the progeny of two intraspecific and three interspecific crosses were examined in the frequency of the paternal transmission of mtDNA, using closely related species of the melanogaster species subgroup. Types of mtDNA in the progeny of the individual backcrosses of F(1) females were analyzed by selective amplification of paternal mtDNA.

Involvement of Drosophila Sir2-like genes in the regulation of life span.

In Drosophila melanogaster, the Sir2 gene and four Sir2-like genes have been found to be homologous to yeast SIR2 genes. To examine whether the fly Sir2, CG5216, and two Sir2-like genes, CG5085 and CG6284, affect life span, we suppressed their expression using RNAi. Decreased expression of the Sir2 and Sir2-like genes in all cells caused lethality during development.

Complete nucleotide sequence of the A+T-rich region of Drosophila mauritiana mitochondrial DNA.

We determined the complete nucleotide sequence of the A+T-rich region of the maII type of mtDNA in D. mauritiana. The nucleotide sequence was found to contain 3,206 bp.

Detection of deletions flanked by short direct repeats in mitochondrial DNA of aging Drosophila.

Cumulative damage due to reactive oxygen species (ROS) in mitochondria, especially in mitochondrial DNA (mtDNA), would result in a decrease in mitochondrial respiratory function and contributes to the age-related decline in the physiological functioning of organisms. Previously, we reported the tissue-specific accumulation of deleted mtDNA with age in Drosophila melanogaster. In the present study, to understand the mechanism by which mtDNA deletion is generated with age, nucleotide sequences of deleted mtDNA were determined.

Nucleotide sequence variation is frequent in the mitochondrial DNA displacement loop region of individual human tumor cells.

The mitochondrial DNA (mtDNA) displacement loop (D-loop) regions of 76 various tumor cell lines were examined to investigate the existence of a specific relationship between a somatic mtDNA sequence and initiation and/or progression of a tumor. Based on molecular cloning-sequencing analysis, a nucleotide sequence in the D-loop region in each cell line was found to be homoplasmic. Several site-specific nucleotide variations were found in stomach and liver tumor cell lines more frequently than those in other tumor cell lines.

Accumulation of deleted mitochondrial DNA in aging Drosophila melanogaster.

Cumulative damage in mitochondria by reactive oxygen species is thought to result in a decrease in mitochondrial respiratory function and to contribute to the age-related decline in the physiological function of organisms. The mitochondrial genome is also subjected to damage with age through deletions. The accumulation of deleted mitochondrial DNA (mtDNA) has been observed in various animals, but still remains unclear in insects.

Evolution of the A+T-rich region of mitochondrial DNA in the melanogaster species subgroup of Drosophila.

We determined the nucleotide sequences of two regions in the A+T-rich region of mitochondrial DNA (mtDNA) in the siI and siII types of D. simulans, the maII type of D. mauritiana, and D.