scholarly journals Interactions between cytoplasmic and nuclear genomes confer sex-specific effects on lifespan in Drosophila melanogaster

2019 ◽  
Author(s):  
Rebecca C. Vaught ◽  
Susanne Voigt ◽  
Ralph Dobler ◽  
David J. Clancy ◽  
Klaus Reinhardt ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Large Body ◽  
Phenotypic Expression ◽  
Epistatic Interactions ◽  
Relative Contribution ◽  
Specific Effects ◽  
Nuclear Interactions ◽  
Sources Of Variation ◽  
Mitochondrial Sequences

ABSTRACTA large body of studies has demonstrated that genetic variation that resides outside of the cell nucleus can affect the organismal phenotype. The cytoplasm is home to the mitochondrial genome and, at least in arthropods, often hosts intracellular endosymbiotic bacteria such as Wolbachia. While numerous studies have implicated epistatic interactions between cytoplasmic and nuclear genetic variation as key to mediating patterns of phenotypic expression, two outstanding questions remain. Firstly, the relative contribution of mitochondrial genetic variation to other cytoplasmic sources of variation in shaping the phenotypic outcomes of cyto-nuclear interactions remains unknown. Secondly, it remains unclear whether the outcomes of cyto-nuclear interactions will manifest differently across the two sexes, as might be predicted given that cytoplasmic genomes are screened by natural selection only through females as a consequence of their maternal inheritance. Here, we address these questions, creating a fully-crossed set of replicated cyto-nuclear populations derived from three geographically distinct populations of Drosophila melanogaster, and measuring the lifespan of males and females from each population. We report cyto-nuclear interactions for lifespan, with the outcomes of these interactions differing across the sexes, and reconcile these findings with information on the full mitochondrial sequences and Wolbachia infection status of each of the populations.

scholarly journals The role of APETALA1 in petal number robustness

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Marie Monniaux ◽  
Bjorn Pieper ◽  
Sarah M McKim ◽  
Anne-Lise Routier-Kierzkowska ◽  
Daniel Kierzkowski ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Genetic Variation ◽  
Reproductive Success ◽  
Genetic Basis ◽  
Phenotypic Expression ◽  
Specific Difference ◽  
Closely Related Species ◽  
Epistatic Interactions ◽  
Species Specific

Invariant floral forms are important for reproductive success and robust to natural perturbations. Petal number, for example, is invariant in Arabidopsis thaliana flowers. However, petal number varies in the closely related species Cardamine hirsuta, and the genetic basis for this difference between species is unknown. Here we show that divergence in the pleiotropic floral regulator APETALA1 (AP1) can account for the species-specific difference in petal number robustness. This large effect of AP1 is explained by epistatic interactions: A. thaliana AP1 confers robustness by masking the phenotypic expression of quantitative trait loci controlling petal number in C. hirsuta. We show that C. hirsuta AP1 fails to complement this function of A. thaliana AP1, conferring variable petal number, and that upstream regulatory regions of AP1 contribute to this divergence. Moreover, variable petal number is maintained in C. hirsuta despite sufficient standing genetic variation in natural accessions to produce plants with four-petalled flowers.

scholarly journals Genetic Screens for Factors Involved in the Notum Bristle Loss of Interspecific Hybrids Between Drosophila melanogaster and D. simulans

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 269-282
Author(s):  
Toshiyuki Takano-Shimizu
Keyword(s):  
Drosophila Melanogaster ◽  
Interspecific Cross ◽  
Species Variation ◽  
Genetic Screens ◽  
Pure Species ◽  
Epistatic Interactions ◽  
X Chromosomes ◽  
Powerful Means ◽  
Different Populations ◽  
Deficiency Screening

Abstract Interspecific cross is a powerful means to uncover hidden within- and between-species variation in populations. One example is a bristle loss phenotype of hybrids between Drosophila melanogaster and D. simulans, although both the pure species have exactly the same pattern of bristle formation on the notum. There exists a large amount of genetic variability in the simulans populations with respect to the number of missing bristles in hybrids, and the variation is largely attributable to simulans X chromosomes. Using nine molecular markers, I screened the simulans X chromosome for genetic factors that were responsible for the differences between a pair of simulans lines with high (H) and low (L) missing bristle numbers. Together with duplication-rescue experiments, a single major quantitative locus was mapped to a 13F–14F region. Importantly, this region accounted for most of the differences between H and L lines in three other independent pairs, suggesting segregation of H and L alleles at the single locus in different populations. Moreover, a deficiency screening uncovered several regions with factors that potentially cause the hybrid bristle loss due to epistatic interactions with the other factors.

scholarly journals Female Genotypes Affect Sperm Displacement in Drosophila

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1487-1493 ◽  
Author(s):  
Andrew G Clark ◽  
David J Begun
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Natural Populations ◽  
Isogenic Line ◽  
Female Fitness ◽  
Sperm Displacement ◽  
Extensive Variation ◽  
Polymorphic Genes ◽  
Displacement Parameter ◽  
Competitive Success

Abstract Differential success of sperm is likely to be an important component of fitness. Extensive variation among male genotypes in competitive success of sperm in multiply mated females has been documented for Drosophila melanogaster. However, virtually all previous studies considered the female to be a passive vessel. Nevertheless, under certain conditions female fitness could be determined by her role in mediating use of sperm from multiple males. Here we ask whether females differ among genotypes in their tendency to exhibit last-male precedence. Competition of sperm from two tester male genotypes (bwD and B3-09, a third-chromosome isogenic line from Beltsville, MD) was quantified by doubly mating female lines that had been rendered homozygous for X, second, or third chromosomes isolated from natural populations. The composite sperm displacement parameter, P2′, was highly heterogeneous among lines, whether or not viability effects were compensated, implying the presence of polymorphic genes affecting access of sperm to eggs. Genetic variation of this type is completely neutral in the absence of pleiotropy or interaction between variation in the two sexes.

scholarly journals Genetic variation in the dietary sucrose modulation of enzyme activities in Drosophila melanogaster

1984 ◽  
Vol 43 (3) ◽  
pp. 307-321 ◽  
Author(s):  
Billy W. Geer ◽  
Cathy C. Laurie-Ahlberg
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Enzyme Activities ◽  
Glycogen Synthesis ◽  
Krebs Cycle ◽  
Natural Populations ◽  
Substitution Lines ◽  
Chromosome Substitution Lines ◽  
High Sucrose Diet ◽  
Selection Of

SUMMARYGenetic variation in the modulating effect of dietary sucrose was assessed in Drosophila melanogaster by examining 27 chromosome substitution lines coisogenic for the X and second chromosomes and possessing different third isogenic chromosomes derived from natural populations. An increase in the concentration of sucrose from 0·1% to 5% in modified Sang's medium C significantly altered the activities of 11 of 15 enzyme activities in third instar larvae, indicating that dietary sucrose modulates many, but not all, of the enzymes of D. melanogaster. A high sucrose diet promoted high activities of enzymes associated with lipid and glycogen synthesis and low activities of enzymes of the glycolytic and Krebs cycle pathways, reflecting the physiological requirements of the animal. Analyses of variance revealed significant genetic variation in the degrees to which sucrose modulated several enzyme activities. Analysis of correlations revealed some relationships between enzymes in the genetic effects on the modulation process. These observations suggest that adaptive evolutionary change may depend in part on the selection of enzyme activity modifiers that are distributed throughout the genome.

scholarly journals Genetic variation in Drosophila melanogaster pathogen susceptibility

Parasitology ◽  
2006 ◽  
Vol 132 (6) ◽  
pp. 767-773 ◽  
Author(s):  
M. C. TINSLEY ◽  
S. BLANFORD ◽  
F. M. JIGGINS
Keyword(s):  
Biological Control ◽  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Model Organism ◽  
Resistance Evolution ◽  
Control Programmes ◽  
Host Ecology ◽  
Insect Pathogens ◽  
Immunological Research ◽  
Pathogen Exposure

Genetic variation in susceptibility to pathogens is a central concern both to evolutionary and medical biologists, and for the implementation of biological control programmes. We have investigated the extent of such variation in Drosophila melanogaster, a major model organism for immunological research. We found that within populations, different Drosophila genotypes show wide-ranging variation in their ability to survive infection with the entomopathogenic fungus Beauveria bassiana. Furthermore, striking divergence in susceptibility has occurred between genotypes from temperate and tropical African locations. We hypothesize that this may have been driven by adaptation to local differences in pathogen exposure or host ecology. Genetic variation within populations may be maintained by temporal or spatial variation in the costs and benefits of pathogen defence. Insect pathogens are employed widely as biological control agents and entomopathogenic fungi are currently being developed for reducing malaria transmission by mosquitoes. Our data highlight the need for concern about resistance evolution to these novel biopesticides in vector populations.

Epistatic Interactions Between smell-impaired Loci in Drosophila melanogaster

Genetics ◽  
1998 ◽  
Vol 148 (4) ◽  
pp. 1885-1891 ◽  
Author(s):  
Grażyna M Fedorowicz ◽  
James D Fry ◽  
Robert R H Anholt ◽  
Trudy F C Mackay
Keyword(s):  
Drosophila Melanogaster ◽  
Significant Variation ◽  
P Element ◽  
Olfactory Behavior ◽  
Epistatic Interactions ◽  
Combining Abilities ◽  
Multiple Loci ◽  
Quantitative Genetic ◽  
Half Diallel ◽  
Diallel Design

Abstract Odor-guided behavior is a polygenic trait determined by the concerted expression of multiple loci. Previously, P-element mutagenesis was used to identify single P[lArB] insertions, in a common isogenic background, with homozygous effects on olfactory behavior. Here, we have crossed 12 lines with these smell impaired (smi) mutations in a half-diallel design (excluding homozygous parental genotypes and reciprocal crosses) to produce all possible 66 doubly heterozygous hybrids with P[lArB] insertions at two distinct locations. The olfactory behavior of the transheterozygous progeny was measured using an assay that quantified the avoidance response to the repellent odorant benzaldehyde. There was significant variation in general combining abilities of avoidance scores among the smi mutants, indicating variation in heterozygous effects. Further, there was significant variation among specific combining abilities of each cross, indicating dependencies of heterozygous effects on the smi locus genotypes, i.e., epistasis. Significant epistatic interactions were identified for nine transheterozygote genotypes, involving 10 of the 12 smi loci. Eight of these loci form an interacting ensemble of genes that modulate expression of the behavioral phenotype. These observations illustrate the power of quantitative genetic analyses to detect subtle phenotypic effects and point to an extensive network of epistatic interactions among genes in the olfactory subgenome.

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