Search

Your search keyword '"Dowling, Damian K."' showing total 372 results
Start Over Author "Dowling, Damian K."
372 results on '"Dowling, Damian K."'

4. Assessing the fitness consequences of mitonuclear interactions in natural populations

Author

Hill, Geoffrey E, Havird, Justin C, Sloan, Daniel B, Burton, Ronald S, Greening, Chris, and Dowling, Damian K

Subjects
Biological Sciences, Genetics, Generic health relevance, Affordable and Clean Energy, Adaptation, Physiological, Animals, Ecosystem, Gene Expression Regulation, Genetic Fitness, Mitochondria, Oxygen Consumption, mitochondria, coadaptation, coevolution, epistatic interactions, gene flow, speciation, mitochondrial medicine, fitness, Evolutionary Biology, Biological sciences
Abstract

Metazoans exist only with a continuous and rich supply of chemical energy from oxidative phosphorylation in mitochondria. The oxidative phosphorylation machinery that mediates energy conservation is encoded by both mitochondrial and nuclear genes, and hence the products of these two genomes must interact closely to achieve coordinated function of core respiratory processes. It follows that selection for efficient respiration will lead to selection for compatible combinations of mitochondrial and nuclear genotypes, and this should facilitate coadaptation between mitochondrial and nuclear genomes (mitonuclear coadaptation). Herein, we outline the modes by which mitochondrial and nuclear genomes may coevolve within natural populations, and we discuss the implications of mitonuclear coadaptation for diverse fields of study in the biological sciences. We identify five themes in the study of mitonuclear interactions that provide a roadmap for both ecological and biomedical studies seeking to measure the contribution of intergenomic coadaptation to the evolution of natural populations. We also explore the wider implications of the fitness consequences of mitonuclear interactions, focusing on central debates within the fields of ecology and biomedicine.

Published
2019

10. Sexual Selection Increases Male Behavioral Consistency in Drosophila melanogaster.

Author

Brand, Jack A., Aich, Upama, Yee, Winston K. W., Wong, Bob B. M., and Dowling, Damian K.

Subjects
SEXUAL selection, DROSOPHILA melanogaster, DROSOPHILIDAE, MALES
Abstract

Sexual selection has been suggested to influence the expression of male behavioral consistency. However, despite predictions, direct experimental support for this hypothesis has been lacking. Here, we investigated whether sexual selection altered male behavioral consistency in Drosophila melanogaster —a species with both pre- and postcopulatory sexual selection. We took 1,144 measures of locomotor activity (a fitness-related trait in D. melanogaster) from 286 flies derived from replicated populations that have experimentally evolved under either high or low levels of sexual selection for >320 generations. We found that high sexual selection males were more consistent (decreased within-individual variance) in their locomotor activity than male conspecifics from low sexual selection populations. There were no differences in behavioral consistency between females from the high and low sexual selection populations. Furthermore, while females were more behaviorally consistent than males in the low sexual selection populations, there were no sex differences in behavioral consistency in high sexual selection populations. Our results demonstrate that behavioral plasticity is reduced in males from populations exposed to high levels of sexual selection. Disentangling whether these effects represent an evolved response to changes in the intensity of selection or are manifested through nongenetic parental effects represents a challenge for future research. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

19. Temperature change exerts sex-specific effects on behavioural variation

Author

Brand, Jack A., Yee, Winston K. W., Aitkenhead, Ian J., Martin, Jake M., Polverino, Giovanni, Chown, Steven L., Wong, Bob B. M., Dowling, Damian K., Brand, Jack A., Yee, Winston K. W., Aitkenhead, Ian J., Martin, Jake M., Polverino, Giovanni, Chown, Steven L., Wong, Bob B. M., and Dowling, Damian K.

Abstract

Temperature is a key factor mediating organismal fitness and has important consequences for species' ecology. While the mean effects of temperature on behaviour have been well-documented in ectotherms, how temperature alters behavioural variation among and within individuals, and whether this differs between the sexes, remains unclear. Such effects likely have ecological and evolutionary consequences, given that selection acts at the individual level. We investigated the effect of temperature on individual-level behavioural variation and metabolism in adult male and female Drosophila melanogaster (n = 129), by taking repeated measures of locomotor activity and metabolic rate at both a standard temperature (25°C) and a high temperature (28°C). Males were moderately more responsive in their mean activity levels to temperature change when compared to females. However, this was not true for either standard or active metabolic rate, where no sex differences in thermal metabolic plasticity were found. Furthermore, higher temperatures increased both among- and within-individual variation in male, but not female, locomotor activity. Given that behavioural variation can be critical to population persistence, we suggest that future studies test whether sex differences in the amount of behavioural variation expressed in response to temperature change may result in sex-specific vulnerabilities to a warming climate.

Published
2023
Full Text
View/download PDF

34. Additional file 1 of Fragmentation in mitochondrial genomes in relation to elevated sequence divergence and extreme rearrangements

Author

Feng, Shiqian, Pozzi, Andrea, Stejskal, Vaclav, Opit, George, Yang, Qianqian, Shao, Renfu, Dowling, Damian K., and Li, Zhihong

Abstract

Additional file 1: Fig. S1. The sketch map for NGBs counting. (A) A schematic representation of the rationale behind the calculation of NGBs. We counted only the adjacent genes with the same relative transcription direction as one gene boundary. (B) An example of NGBs counting. The circular chromosome A and B have five genes (gene A, gene B, gene C, gene D, gene E). The gene boundaries for species A are A-B, B-C, C-D, D-E, E-A while those for species B are A-B, B-C, C-E, E-D, D-A. The only matched gene boundary between the two species is A-B. So the NGBs between A and B is 1. We used the same method to calculate the NGBs between two mitochondrial genomes. Fig. S2. Newly constructed phylogenies of booklice. We inferred the phylogenetic relationship of Liposcelis species using mt-genome sequences with four datasets and three softwares. Details were introduced in ���Materials and Methods��� section. The numbers in each node represents BI posterior probability or ML boostrap value for each datasets/methods: PCG123rRNA/MrBayes+PCG123/MrBayes+PCG12rRNA/MrBayes+PCG12/MrBayes+PCG123rRNA/IQtree+PCG123/IQtree+PCG12rRNA/IQtree+PCG12/IQtree+PCG123rRNA/PhyML+PCG123/PhyML+PCG12rRNA/PhyML+PCG12/PhyML. The best substitution models for different methods are listed in Additional file 3: Table S4. All three methods supported the same topology among booklice species. Fig. S3. Agarose gel electrophoresis Long-PCR products of the three booklice. (A) Agarose gel electrophoresis PCR products of L. corrodens KS strain. Amplicons 1-6 are from LcCZLF/LcCZLR, LcCZC1F/LcCZLF, LcCZC1R/LcCZLR, LcCZLF/LcCZLR, LcCZC1F/LcCZLF and LcCZC1R/LcCZLR. Marker (M): 1 kb DNA ladder marker: 10 kb, 8 kb, 6 kb, 5 kb, 4 kb, 3 kb, 2.5 kb, 2 kb, 1.5 kb, 1 kb, 700 bp, 500 bp, 300 bp. 1 ��L Long-PCR product was used for every sample of each run. (B) Agarose gel electrophoreses PCR products of L. pearmani KS strain. Amplicons 1-3, 5-8 are from LpearC1F/LpearC1R, LpearLF/LpearLR, LpearSF/LpearSR, LpearLF/LpearSF, LpearLR/LpearSR, LpearC1F/LpearSR and LpearC1R/LpearSF. (C) Agarose gel electrophoreses PCR products of L. rufa KS strain. Amplicons 1-5 are from LruLF/LruLR, LruLF/LruSR, LruLR/LruSF, LruC1F/LruSF and LruC1R/LruSR.

Published
2022
Full Text
View/download PDF

45. Selection for biparental inheritance of mitochondria under hybridization and mitonuclear fitness interactions

Author

Allison, Tom M., Radzvilavicius, Arunas L., and Dowling, Damian K.

Subjects
Male, 0106 biological sciences, Heredity, Evolution, Inheritance Patterns, DNA, Mitochondrial, 010603 evolutionary biology, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, 03 medical and health sciences, mitonuclear, Animals, heteroplasmy, bet-hedging, Research Articles, 030304 developmental biology, General Environmental Science, 0303 health sciences, hybrid, General Immunology and Microbiology, General Medicine, rare-allele, humanities, Mitochondria, biparental inheritance, Hybridization, Genetic, Female, General Agricultural and Biological Sciences
Abstract

Uniparental inheritance (UPI) of mitochondria predominates over biparental inheritance (BPI) in most eukaryotes. However, examples of BPI of mitochondria, or paternal leakage, are becoming increasingly prevalent. Most reported cases of BPI occur in hybrids of distantly related sub-populations. It is thought that BPI in these cases is maladaptive; caused by a failure of female or zygotic autophagy machinery to recognize divergent male-mitochondrial DNA ‘tags’. Yet recent theory has put forward examples in which BPI can evolve under adaptive selection, and empirical studies across numerous metazoan taxa have demonstrated outbreeding depression in hybrids attributable to disruption of population-specific mitochondrial and nuclear genotypes (mitonuclear mismatch). Based on these developments, we hypothesize that BPI may be favoured by selection in hybridizing populations when fitness is shaped by mitonuclear interactions. We test this idea using a deterministic, simulation-based population genetic model and demonstrate that BPI is favoured over strict UPI under moderate levels of gene flow typical of hybridizing populations. Our model suggests that BPI may be stable, rather than a transient phenomenon, in hybridizing populations.

Published
2021

47. Y chromosome-linked variation affects locomotor activity in male Drosophila melanogasterand is robust to differences in thermal environment

Author

Layh, Sean, Nagarajan-Radha, Venkatesh, Lemos, Bernardo, and Dowling, Damian K.

Abstract

Although containing genes important for sex determination, genetic variation within the Y chromosome was traditionally predicted to contribute little to the expression of sexually dimorphic traits. This prediction was shaped by the assumption that the chromosome harbours few protein-coding genes, and that capacity for Y-linked variation to shape adaptation would be hindered by the chromosome’s lack of recombination and holandric inheritance. Consequently, most studies exploring the genotypic contributions to sexually dimorphic traits have focused on the autosomes and X chromosome. Yet, several studies have now demonstrated that the Y chromosome harbours variation affecting male fitness, moderating the expression of hundreds of genes across the nuclear genome. Furthermore, emerging results have shown that expression of this Y-linked variation may be sensitive to environmental heterogeneity, leading to the prediction that Y-mediated gene-by-environment interactions will shape the expression of sexually dimorphic phenotypes. We tested this prediction, investigating whether genetic variation across six distinct Y chromosome haplotypes affects the expression of locomotor activity, at each of two temperatures (20 and 28 °C) in male fruit flies (Drosophila melanogaster). Locomotor activity is a sexually dimorphic trait in this species, previously demonstrated to be under intralocus sexual conflict. We demonstrate Y haplotype effects on male locomotor activity, but the rank order and magnitude of these effects were unaltered by differences in temperature. Our study contributes to a growing number of studies demonstrating Y-linked effects moderating expression of traits evolving under sexually antagonistic selection, suggesting a role for the Y chromosome in shaping outcomes of sexual conflict.

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results