scholarly journals Divergent mitochondrial and nuclear OXPHOS genes are candidates for genetic incompatibilities inFicedulaFlycatchers

2019 ◽  
Author(s):  
Eva van der heijden ◽  
S. Eryn McFarlane ◽  
Tom van der Valk ◽  
Anna Qvarnström
Keyword(s):  
Energy Metabolism ◽  
Nuclear Dna ◽  
Resting Metabolic Rate ◽  
Population Expansion ◽  
Nuclear Genes ◽  
F1 Hybrids ◽  
Relative Role ◽  
Synonymous Mutations ◽  
Genes Encoding ◽  
Hybrid Dysfunction

AbstractHybrid dysfunction is an important source of reproductive isolation between emerging species. Bateson-Dobzhansky-Muller incompatibilities are theoretically well-recognized as the underlying cause of low hybrid dysfunction. However, especially in wild populations, little empirical evidence exists for which genes are involved in such incompatibilities. The relative role of ecological divergence in causing the build-up of genetic incompatibilities in relation to other processes such as genomic conflict therefore remains largely unknown. Genes involved in energy metabolism are potential candidates for genetic incompatibilities, since energy metabolism depends on co-expression of mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) leading to mitonuclear coadaptation. When mitochondrial and nuclear genes lacking a co-evolutionary history appear together in hybrids, incompatibilities could arise.Ficedulaflycatcher F1 hybrids have a higher resting metabolic rate (RMR) compared to the parental species, which could be a sign of genetic incompatibilities between energy metabolism genes that diverged in response to environmental differences while the species were in allopatry. Based on sequences of 15 mitochondrial genes of 264 individuals, we show that the two species have divergent mtDNA caused by the build-up of mainly synonymous mutations and a few non-synonymous mutations. Pied flycatcher mitogenomes show evidence of non-neutrality, indicating a selective sweep or population expansion. There is little variation in the nuclear OXPHOS-related proteins and no significant deviation from neutrality, however, specific codon identified sites might be under positive selection in both mitochondrial and nuclear genes encoding OXPHOS proteins for complex I and III. Taken together, these diverged mitonuclear genes therefore constitute possible candidates underlying, at least part of the genetic incompatibilities that cause hybrid dysfunction in crosses between collared and pied flycatchers.

scholarly journals High-level expression and molecular cloning of genes encoding Candida tropicalis peroxisomal proteins.

1984 ◽  
Vol 4 (10) ◽  
pp. 2136-2141 ◽  
Author(s):  
T Kamiryo ◽  
K Okazaki
Keyword(s):  
Oleic Acid ◽  
Candida Tropicalis ◽  
Nuclear Dna ◽  
Apparent Molecular Weight ◽  
Dna Library ◽  
Coding Regions ◽  
Chain Acyl ◽  
Genes Encoding ◽  
High Level ◽  
Acyl Coenzyme A

The development of peroxisomes in the cells of Candida tropicalis grown on oleic acid was accompanied by a markedly high expression of peroxisomal proteins. On the basis of this finding, the nuclear DNA library of this yeast was screened by differential hybridization, and 102 clones of oleic acid-inducible sequences were isolated. Seven coding regions were found to form clusters in three stretches of the genomic DNA. Five of the regions were identified as genes for peroxisomal polypeptides (PXPs). The coding sequence for PXP-2 hybrid selected an additional mRNA for PXP-4, the subunit of long-chain acyl coenzyme A oxidase, which was the most abundant PXP. PXP-2 and PXP-4 were close in apparent molecular weight and generated similar peptides when digested with a protease. The gene for PXP-4 was adjacent to that for PXP-2 on the genome and also hybridized to the mRNA coding for PXP-5. These and other similar results suggest that the genes for the peroxisomal proteins of this organism arose by duplication of a few ancestral genes.

The heart in neuromuscular disease: primary mitochondrial diseases

ESC CardioMed ◽  
2018 ◽  
pp. 1528-1530
Author(s):  
Denis Duboc
Keyword(s):  
Neuromuscular Disease ◽  
Nuclear Dna ◽  
Single Cells ◽  
Mitochondrial Diseases ◽  
Respiratory Chain Complexes ◽  
Base Pairs ◽  
Daughter Cells ◽  
Dna Molecule ◽  
Chain Complexes ◽  
Genes Encoding

Mitochondria are responsible for energy production in most eukaryotic cells. Each cell contains at least one mitochondrion and every mitochondrion contains two to ten copies of a circular DNA molecule (mitochondrial DNA or mtDNA). Cardiomyocytes contain approximately 10,000 mtDNA copies. MtDNA is composed of around 16,500 base pairs and 37 genes encoding 13 subunits of the respiratory chain complexes I, III, IV, and V, 22 mitochondrial tRNAs and 2 rRNAs. With each cell division, mitochondria and mtDNA are randomly distributed to daughter cells. In humans, mitochondria are inherited exclusively from the mother. In healthy people mtDNA copies are usually identical at birth (homoplasmy) but with ageing, mtDNA is particularly prone to somatic mutation because, unlike nuclear DNA, it is continuously replicated, even in non-dividing tissues such as myocardium. This can lead to the propagation of somatic mutations within single cells by a process called clonal expansion. In addition, mtDNA lacks an extensive DNA repair mechanism.

scholarly journals Minimization of energy transduction confers resistance to phosphine in the rice weevil, Sitophilus oryzae

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kyeongnam Kim ◽  
Jeong Oh Yang ◽  
Jae-Yoon Sung ◽  
Ji-Young Lee ◽  
Jeong Sun Park ◽  
...  
Keyword(s):  
Cancer Metabolism ◽  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Resistance Mechanism ◽  
Energy Transduction ◽  
Metabolic Reprogramming ◽  
Rice Weevil ◽  
Altered Expression ◽  
Synonymous Mutations ◽  
Genes Encoding

Abstract Infestation of phosphine (PH3) resistant insects threatens global grain reserves. PH3 fumigation controls rice weevil (Sitophilus oryzae) but not highly resistant insect pests. Here, we investigated naturally occurring strains of S. oryzae that were moderately resistant (MR), strongly resistant (SR), or susceptible (wild-type; WT) to PH3 using global proteome analysis and mitochondrial DNA sequencing. Both PH3 resistant (PH3–R) strains exhibited higher susceptibility to ethyl formate-mediated inhibition of cytochrome c oxidase than the WT strain, whereas the disinfectant PH3 concentration time of the SR strain was much longer than that of the MR strain. Unlike the MR strain, which showed altered expression levels of genes encoding metabolic enzymes involved in catabolic pathways that minimize metabolic burden, the SR strain showed changes in the mitochondrial respiratory chain. Our results suggest that the acquisition of strong PH3 resistance necessitates the avoidance of oxidative phosphorylation through the accumulation of a few non-synonymous mutations in mitochondrial genes encoding complex I subunits as well as nuclear genes encoding dihydrolipoamide dehydrogenase, concomitant with metabolic reprogramming, a recognized hallmark of cancer metabolism. Taken together, our data suggest that reprogrammed metabolism represents a survival strategy of SR insect pests for the compensation of minimized energy transduction under anoxic conditions. Therefore, understanding the resistance mechanism of PH3–R strains will support the development of new strategies to control insect pests.

scholarly journals Developmental Genes and Malformations in the Hypothalamus

2020 ◽  
Vol 14 ◽  
Author(s):  
Carmen Diaz ◽  
Luis Puelles
Keyword(s):  
Transcription Factors ◽  
Energy Metabolism ◽  
Molecular Mechanisms ◽  
Review Article ◽  
Pituitary Development ◽  
Forebrain Development ◽  
Physiological Processes ◽  
Brain Malformations ◽  
Clinical Complexity ◽  
Genes Encoding

The hypothalamus is a heterogeneous rostral forebrain region that regulates physiological processes essential for survival, energy metabolism, and reproduction, mainly mediated by the pituitary gland. In the updated prosomeric model, the hypothalamus represents the rostralmost forebrain, composed of two segmental regions (terminal and peduncular hypothalamus), which extend respectively into the non-evaginated preoptic telencephalon and the evaginated pallio-subpallial telencephalon. Complex genetic cascades of transcription factors and signaling molecules rule their development. Alterations of some of these molecular mechanisms acting during forebrain development are associated with more or less severe hypothalamic and pituitary dysfunctions, which may be associated with brain malformations such as holoprosencephaly or septo-optic dysplasia. Studies on transgenic mice with mutated genes encoding critical transcription factors implicated in hypothalamic-pituitary development are contributing to understanding the high clinical complexity of these pathologies. In this review article, we will analyze first the complex molecular genoarchitecture of the hypothalamus resulting from the activity of previous morphogenetic signaling centers and secondly some malformations related to alterations in genes implicated in the development of the hypothalamus.

scholarly journals Pliocene Origin, Ice Ages and Postglacial Population Expansion Have Influenced a Panmictic Phylogeography of the European Bee-Eater Merops apiaster

Diversity ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 12 ◽  
Author(s):  
Carina Carneiro de Melo Moura ◽  
Hans-Valentin Bastian ◽  
Anita Bastian ◽  
Erjia Wang ◽  
Xiaojuan Wang ◽  
...  
Keyword(s):  
Genetic Differentiation ◽  
Nuclear Dna ◽  
Bird Species ◽  
Population Expansion ◽  
Genetic Connectivity ◽  
Middle Pleistocene ◽  
Ice Ages ◽  
Breeding Sites ◽  
Late Tertiary ◽  
Merops Apiaster

Oscillations of periods with low and high temperatures during the Quaternary in the northern hemisphere have influenced the genetic composition of birds of the Palearctic. During the last glaciation, ending about 12,000 years ago, a wide area of the northern Palearctic was under lasting ice and, consequently, breeding sites for most bird species were not available. At the same time, a high diversity of habitats was accessible in the subtropical and tropical zones providing breeding grounds and refugia for birds. As a result of long-term climatic oscillations, the migration systems of birds developed. When populations of birds concentrated in refugia during ice ages, genetic differentiation and gene flow between populations from distinct areas was favored. In the present study, we explored the current genetic status of populations of the migratory European bee-eater. We included samples from the entire Palearctic-African distribution range and analyzed them via mitochondrial and nuclear DNA markers. DNA data indicated high genetic connectivity and panmixia between populations from Europe, Asia and Africa. Negative outcomes of Fu’s Fs and Tajima’s D tests point to recent expansion events of the European bee-eater. Speciation of Merops apiaster started during the Pliocene around three million years ago (Mya), with the establishment of haplotype lineages dated to the Middle Pleistocene period circa 0.7 Mya. M. apiaster, which breed in Southern Africa are not distinguished from their European counterparts, indicating a recent separation event. The diversification process of the European bee-eater was influenced by climatic variation during the late Tertiary and Quaternary. Bee-eaters must have repeatedly retracted to refugia in the Mediterranean and subtropical Africa and Asia during ice ages and expanded northwards during warm periods. These processes favored genetic differentiation and repeated lineage mixings, leading to a genetic panmixia, which we still observe today.

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