scholarly journals Genomic analysis of European Drosophila melanogaster populations reveals longitudinal structure, continent-wide selection, and previously unknown DNA viruses

2018 ◽  
Author(s):  
Martin Kapun ◽  
Maite G. Barrón ◽  
Fabian Staubach ◽  
Darren J. Obbard ◽  
R. Axel W. Wiberg ◽  
...  

AbstractGenetic variation is the fuel of evolution, with standing genetic variation especially important for short-term evolution and local adaptation. To date, studies of spatio-temporal patterns of genetic variation in natural populations have been challenging, as comprehensive sampling is logistically difficult, and sequencing of entire populations costly. Here, we address these issues using a collaborative approach, sequencing 48 pooled population samples from 32 locations, and perform the first continent-wide genomic analysis of genetic variation in European Drosophila melanogaster. Our analyses uncover longitudinal population structure, provide evidence for continent-wide selective sweeps, identify candidate genes for local climate adaptation, and document clines in chromosomal inversion and transposable element frequencies. We also characterise variation among populations in the composition of the fly microbiome, and identify five new DNA viruses in our samples.

2020 ◽  
Vol 37 (9) ◽  
pp. 2661-2678 ◽  
Author(s):  
Martin Kapun ◽  
Maite G Barrón ◽  
Fabian Staubach ◽  
Darren J Obbard ◽  
R Axel W Wiberg ◽  
...  

Abstract Genetic variation is the fuel of evolution, with standing genetic variation especially important for short-term evolution and local adaptation. To date, studies of spatiotemporal patterns of genetic variation in natural populations have been challenging, as comprehensive sampling is logistically difficult, and sequencing of entire populations costly. Here, we address these issues using a collaborative approach, sequencing 48 pooled population samples from 32 locations, and perform the first continent-wide genomic analysis of genetic variation in European Drosophila melanogaster. Our analyses uncover longitudinal population structure, provide evidence for continent-wide selective sweeps, identify candidate genes for local climate adaptation, and document clines in chromosomal inversion and transposable element frequencies. We also characterize variation among populations in the composition of the fly microbiome, and identify five new DNA viruses in our samples.


Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1487-1493 ◽  
Author(s):  
Andrew G Clark ◽  
David J Begun

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.


1984 ◽  
Vol 43 (3) ◽  
pp. 307-321 ◽  
Author(s):  
Billy W. Geer ◽  
Cathy C. Laurie-Ahlberg

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.


1980 ◽  
Vol 77 (2) ◽  
pp. 1073-1077 ◽  
Author(s):  
C. C. Laurie-Ahlberg ◽  
G. Maroni ◽  
G. C. Bewley ◽  
J. C. Lucchesi ◽  
B. S. Weir

2019 ◽  
Author(s):  
Rhastin A. D. Castro ◽  
Amanda Ross ◽  
Lujeko Kamwela ◽  
Miriam Reinhard ◽  
Chloé Loiseau ◽  
...  

AbstractFluoroquinolones (FQ) form the backbone in experimental treatment regimens against drug-susceptible tuberculosis. However, little is known on whether the genetic variation present in natural populations ofMycobacterium tuberculosis(Mtb) affects the evolution of FQ-resistance (FQ-R). To investigate this question, we used a set ofMtbstrains that included nine genetically distinct drug-susceptible clinical isolates, and measured their frequency of resistance to the FQ ofloxacin (OFX)in vitro. We found that theMtbgenetic background led to differences in the frequency of OFX-resistance (OFX-R) that spanned two orders of magnitude and substantially modulated the observed mutational profiles for OFX-R. Furtherin vitroassays showed that the genetic background also influenced the minimum inhibitory concentration and the fitness effect conferred by a given OFX-R mutation. To test the clinical relevance of ourin vitrowork, we surveyed the mutational profile for FQ-R in publicly available genomic sequences from clinicalMtbisolates, and found substantialMtblineage-dependent variability. Comparison of the clinical and thein vitromutational profiles for FQ-R showed that 45% and 19% of the variability in the clinical frequency of FQ-RgyrAmutations in Lineage 2 and Lineage 4 strains, respectively, can be attributed to howMtbevolves FQ-Rin vitro. As theMtbgenetic background strongly influenced the evolution of FQ-Rin vitro, we conclude that the genetic background ofMtbalso impacts the evolution of FQ-R in the clinic.SignificanceNewer generations of fluoroquinolones form the backbone in many experimental treatment regimens againstM. tuberculosis(Mtb). While the genetic variation in natural populations ofMtbcan influence resistance evolution to multiple different antibiotics, it is unclear whether it modulates fluoroquinolone-resistance evolution as well. Using a combination ofin vitroassays coupled with genomic analysis of clinical isolates, we provide the first evidence illustrating theMtbgenetic background’s substantial role in fluoroquinolone-resistance evolution, and highlight the importance of bacterial genetics when studying the prevalence of fluoroquinolone-resistance inMtb. Our work may provide insights into how to maximize the timespan in which fluoroquinolones remain effective in clinical settings, whether as part of current standardized regimens, or in new regimens againstMtb.


2017 ◽  
Vol 5 (39) ◽  
Author(s):  
Aude Rochefort ◽  
Sarrah Boukthir ◽  
Séverine Moullec ◽  
Alexandra Meygret ◽  
Yahia Adnani ◽  
...  

ABSTRACT While the incidence and invasiveness of type emm75 group A Streptococcus (GAS) infections increased in French Brittany during 2013, we sequenced and analyzed the genomes of three independent strains isolated in 2009, 2012, and 2014, respectively. In this short-term evolution, genomic analysis evidenced mainly the integration of new phages encoding virulence factors.


Genetics ◽  
1999 ◽  
Vol 152 (4) ◽  
pp. 1605-1614 ◽  
Author(s):  
Michael E Zwick ◽  
Jennifer L Salstrom ◽  
Charles H Langley

Abstract Genetic variation in nondisjunction frequency among X chromosomes from two Drosophila melanogaster natural populations is examined in a sensitized assay. A high level of genetic variation is observed (a range of 0.006-0.241). Two naturally occurring variants at the nod locus, a chromokinesin required for proper achiasmate chromosome segregation, are significantly associated with an increased frequency of nondisjunction. Both of these polymorphisms are found at intermediate frequency in widely distributed natural populations. To account for these observations, we propose a general model incorporating unique opportunities for meiotic drive during female meiosis. The oötid competition model can account for both high mean rates of female-specific nondisjunction in Drosophila and humans as well as the standing genetic variation in this critical fitness character in natural populations.


2016 ◽  
Author(s):  
I.A. Kozeretska ◽  
V. Bondarenko ◽  
V.I. Shulga ◽  
S.V. Serga ◽  
A.I. Rozhok ◽  
...  

AbstractThe Drosophila melanogaster P transposable element provides one of the best cases of horizontal transfer of a mobile DNA sequence in eukaryotes. Invasion of natural populations by the P element has led to a syndrome of phenotypes known as “P-M hybrid dysgenesis” that emerges when strains differing in their P element composition mate and produce offspring. Despite extensive research on many aspects of P element biology, questions remain about the stability and genomic basis of variation in P-M dysgenesis phenotypes. Here we report the P-M status for a number of populations sampled recently from Ukraine that appear to be undergoing a shift in their P element composition. Gondal dysgenesis assays reveal that Ukrainian populations of D. melanogaster are currently dominated by the P’ cytotype, a cytotype that was previously thought to be rare in nature, suggesting that a new active form of the P element has recently spread in this region. We also compared gondal dysgenesis phenotypes and genomic P element predictions for isofemale strains obtained from three worldwide populations of D. melanogaster in order to guide further work on the molecular basis of differences in cytotype status across populations. We find that the number of euchromatic P elements per strain can vary significantly across populations but that total P element numbers are not strongly correlated with the degree of gondal dysgenesis. Our work shows that rapid changes in cytotype status can occur in natural populations of D. melanogaster, and informs future efforts to decode the genomic basis of geographic and temporal differences in P element induced phenotypes.


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