Recent studies of mitochondrial DNA (mtDNA) variation in mammals and Drosophila have shown an excess amino acid within species (replacement polymorphism) relative to the number silent replacement differences fixed between species. To examine further this pattern nonneutral mtDNA evolution, we present sequence data for ND3 ND5 genes from 59 lines melanogaster 29 D. simulans. Of interest are frequency spectra polymorphisms, potential among taxa departures neutral expectations. The show no...

▪ Abstract The reconstruction of evolutionary trees from mitochondrial DNA (mtDNA) data is a common tool with which to infer the relationships living organisms. wide use mtDNA stems ease getting new sequence for set orthologus genes and availability many existing sequences array species. In this review we argue that developing fuller understanding biology mitochondria essential rigorous application inferences about history species or populations. Though much progress has been made in...

Mitochondrial transcription, translation, and respiration require interactions between genes encoded in two distinct genomes, generating the potential for mutations nuclear mitochondrial genomes to interact epistatically cause incompatibilities that decrease fitness. Mitochondrial-nuclear epistasis fitness has been documented within populations species of diverse taxa, but rarely genetic or mechanistic basis these mitochondrial–nuclear elucidated, limiting our understanding which harbor...

▪ Abstract Mitochondrial DNA (mtDNA) exists in a nested hierarchy of populations. There are multiple mtDNAs within each mitochondrion, population mitochondria cell, oocytes reproductive female, females population, and so on up through species higher clades. The metabolic properties make them highly mutagenic environments for the naked, circular that lie them. This mutational pressure introduces mtDNA variation (i.e., heteroplasmy) into cytoplasmic cell lineages particularly prone to decay...

We investigated the effects that habitat variation has on structure and dynamics of a hybrid zone between two closely related crickets in Connecticut. A collecting protocol was developed which were sampled from characteristic habitats either side distinct types within zone. Presumptive pure Gryllus pennsylvanicus fields northwestern Connecticut represent "inland" populations. "Pure" firmus beaches along coast "coastal" Crickets different soil types: "loam" populations loamy soils "sand"...

Abstract To test hypotheses of neutral evolution mitochondrial DNA (mtDNA), nucleotide sequences were determined for 1515 base pairs the NADH dehydrogenase subunit 5 (ND5) gene in 29 lines Drosophila melanogaster and 9 its sibling species simulans. In contrast to patterns nuclear genes, where D. generally exhibits much less polymorphism, number segregating sites was slightly higher a global sample nine ND5 (s = 8) than simulans 6). When compared variation at loci, mtDNA does not depart from...

Dietary restriction (DR) is the most consistent means of extending longevity in a wide range organisms. A growing body literature indicates that mitochondria play an important role extension by DR, but impact mitochondrial genotypes on DR process have received little attention. Mitochondrial function requires proper integration gene products from their own genomes (mtDNA) and nuclear genome as well metabolic state cell, which heavily influenced diet. These three-way...

Background: Consumer nanotechnology is a growing industry. Silver nanoparticles are the most common nanomaterial added to commercially available products, so understanding influence that size has on toxicity integral safe use of these new products. This study examined silver particle Drosophila egg development by comparing both nanoscale and conventional-sized particles. Methods: The assays were conducted exposing eggs concentrations ranging from 10 ppm 100 silver. Size, chemistry,...

Mitochondrial (mtDNA) and nuclear genes have to operate in a coordinated manner maintain organismal function, the regulation of this homeostasis presents substantial source potential epistatic (G × G) interactions. How these interactions shape fitness landscape is poorly understood. Here we developed novel mitonuclear epistasis model, using selected strains Drosophila Genetic Reference Panel (DGRP) mitochondrial genomes from within melanogaster D. simulans test hypothesis that mtDNA nDNA...

Abstract Theoretical and empirical studies have shown that selection cannot maintain a joint nuclear-cytoplasmic polymorphism within population except under restrictive conditions of frequency-dependent or sex-specific selection. These conclusions are based on fitness interactions between diploid autosomal locus haploid cytoplasmic locus. We develop model transmission X chromosomes cytoplasms through simulation show polymorphisms can be maintained by X-cytoplasm interactions. test aspects...

The cytochrome c oxidase enzyme (COX) is comprised of 10 nuclear‐encoded subunits and three mito‐chondrial‐encoded in close physical association the inner mitochondrial membrane. COX passes electrons from to molecular oxygen pumps protons into space for ATP production. Selection on nuclear‐mitochondrial interactions within species should lead coadaptation proteins comprising this important enzyme. Under model, there be relatively little disruption activity when genomes are crossed among...

The mitochondrial DNA of the Atlantic cod (Gadus morhua) contains a tandem array 40-bp repeats in D-loop region molecule. Variation among molecules copy number these results mtDNA length variation and heteroplasmy (the presence more than one form an individual). In sample fish collected from different localities around Iceland off George's Bank, each individual was heteroplasmic for two or mtDNAs ranging repeat (common) to six (rare). An earlier report on sturgeon (Acipenser transmontanus)...

We have examined mitochondrial DNA (mtDNA) restriction-site variation within and between populations of fall-adult field crickets across a narrow hybrid zone in Connecticut.Our analysis reveals two distinct mtDNA lineages, each consisting single common genotype together with one or more rare genotypes.Outside the zone, association species designation is nearly perfect.The A lineage corresponds to Gryllus pennsylvanicus B G. firmus.However, firmus individuals from coastal Connecticut...

ABSTRACT This paper presents the results of a single generation study transmission genetics mitochondrial DNA in field cricket Gryllus firmus. In this species, individuals heteroplasmic for at least two different-sized genomes can be collected easily from natural populations. The frequencies mtDNA size variants females and samples their offspring were estimated by densitometry autoradiographs. variance genotype among indicates that, through genetic drift, fixation would take several hundred...

Under the mitochondrial theory of aging, physiological decline with age results from accumulated cellular damage produced by reactive oxygen species generated during electron transport in mitochondrion. A large body literature has documented age-specific declines function that are consistent this theory, but relatively few studies have been able to distinguish cause consequence association between and aging. Since is jointly encoded (mtDNA) nuclear genes, genetics aging should be controlled...

Rapid growth in nanomaterial manufacturing is raising concerns about potential adverse effects on the environment. Nanoparticle contact with intact organisms wild may lead to different biological responses than those observed laboratory cell-based toxicity assays. In nature, scale and chemistry of nanoparticles coupled surface properties, texture, behaviors will influence biologically significant exposure ultimate toxicity. We used larval adult Drosophila melanogaster study carbon under...

Despite growing interest in species' range shifts, little is known about the ecological and evolutionary factors that control geographic boundaries. We investigated processes maintain northern limit of mud fiddler crab (Uca pugnax) at North Scituate, Massachusetts, USA (42°14′ N), located 60 km north Cape Cod. Larvae from five populations Massachusetts were reared under controlled temperatures to test whether cooler water near edge this inhibits planktonic development. Few larvae completed...

Efficient mitochondrial function requires physical interactions between the proteins encoded by and nuclear genomes. Coevolution these genomes may result in accumulation of incompatibilities divergent lineages. We test whether mitochondrial-nuclear have accumulated within Drosophila melanogaster species subgroup combining lineages quantifying effects on relative fitness. Precise placement nine mtDNAs from D. melanogaster, simulans, mauritiana into two genetic backgrounds reveals significant...

The mitochondrial DNA's of two closely related cricket species (genus Gryllus) share a size polymorphism as evidenced by analysis restriction fragment patterns. Moreover, 12 100 field-collected crickets are heteroplasmic, that is these individuals have more than one class DNA. No heteroplasmy for site variation observed. Intraindividual in DNA provides useful marker studying the transmission genetics Available data on patterns mothers and offspring suggest random segregation variants does...

Abstract We report that patterns of nonneutral DNA sequence evolution among published nuclear and mitochondrially encoded protein-coding loci differ significantly in animals. Whereas an apparent excess amino acid polymorphism is seen most (25/31) mitochondrial genes, this pattern fewer than half (15/36) the data sets. This differentiation even greater sets with significant departures from neutrality (14/15 vs. 1/6). Using forward simulations, we examined using parameters chosen to mimic...