scholarly journals Parallel Evolution of Cold Tolerance Within Drosophila melanogaster

2016 ◽  
Author(s):  
John E. Pool ◽  
Dylan T. Braun ◽  
Justin B. Lack
Keyword(s):  
Drosophila Melanogaster ◽  
Cold Tolerance ◽  
South African ◽  
Climate Adaptation ◽  
Parallel Evolution ◽  
Frequency Change ◽  
Nucleotide Polymorphisms ◽  
Tropical Africa ◽  
Single Nucleotide ◽  
Cold Adapted

ABSTRACTDrosophila melanogaster originated in tropical Africa before expanding into strikingly different temperate climates in Eurasia and beyond. Here, we show that elevated cold tolerance has arisen at least three times within this species: beyond the well-studied non-African case, we show that populations from the highlands of Ethiopia and South Africa have significantly increased cold tolerance as well. We observe greater cold tolerance in outbred versus inbred flies, but only in populations with higher inversion frequencies. Each cold-adapted population shows lower inversion frequencies than a closely-related warm-adapted population, suggesting that inversion frequencies may decrease with altitude in addition to latitude. Using the FST-based “Population Branch Excess” statistic (PBE), we found only limited evidence for parallel genetic differentiation at the scale of ~4 kb windows, specifically between Ethiopian and South African cold-adapted populations. And yet, when we looked for single nucleotide polymorphisms (SNPs) with codirectional frequency change in two or three cold-adapted populations, strong genomic enrichments were observed from all comparisons. These findings could reflect an important role for selection on standing genetic variation leading to “soft sweeps”. One SNP showed sufficient codirectional frequency change in all cold-adapted populations to achieve experiment-wide significance: an intronic variant in the synaptic gene Prosap. More generally, proteins involved in neurotransmission were enriched as potential targets of parallel adaptation. The ability to study cold tolerance evolution in a parallel framework will enhance this classic study system for climate adaptation.

Genomic Signatures of Selection along a Climatic Gradient in the Northern Range Margin of the White-Footed Mouse (Peromyscus leucopus)

2019 ◽  
Vol 110 (6) ◽  
pp. 684-695 ◽  
Author(s):  
Alan Garcia-Elfring ◽  
Rowan D H Barrett ◽  
Virginie Millien
Keyword(s):  
Climate Adaptation ◽  
Peromyscus Leucopus ◽  
Parallel Evolution ◽  
Thermal Adaptation ◽  
Synaptic Function ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Northern Margin ◽  
Genomic Signatures ◽  
Genomic Regions

Abstract Identifying genetic variation involved in thermal adaptation is likely to yield insights into how species adapt to different climates. Physiological and behavioral responses associated with overwintering (e.g., torpor) are thought to serve important functions in climate adaptation. In this study, we use 2 isolated Peromyscus leucopus lineages on the northern margin of the species range to identify single nucleotide polymorphisms (SNPs) showing a strong environmental association and test for evidence of parallel evolution. We found signatures of clinal selection in each lineage, but evidence of parallelism was limited, with only 2 SNPs showing parallel allele frequencies across transects. These parallel SNPs map to a gene involved in protection against iron-dependent oxidative stress (Fxn) and to a gene with unknown function but containing a forkhead-associated domain (Fhad1). Furthermore, within transects, we find significant clinal patterns in genes enriched for functions associated with glycogen homeostasis, synaptic function, intracellular Ca2+ balance, H3 histone modification, as well as the G2/M transition of cell division. Our results are consistent with recent literature on the cellular and molecular basis of climate adaptation in small mammals and provide candidate genomic regions for further study.

Assessing single nucleotide polymorphism selection methods for the development of a low-density panel optimized for imputation in South African Drakensberger beef cattle

2021 ◽  
Author(s):  
Simon F Lashmar ◽  
Donagh P Berry ◽  
Rian Pierneef ◽  
Farai C Muchadeyi ◽  
Carina Visser
Keyword(s):  
South African ◽  
Clustering Algorithm ◽  
Imputation Accuracy ◽  
Developed Countries ◽  
Genotype Imputation ◽  
Selection Strategy ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Single Nucleotide Polymorphism Selection ◽  
The Mean

Abstract A major obstacle in applying genomic selection (GS) to uniquely adapted local breeds in less-developed countries has been the cost of genotyping at high densities of single nucleotide polymorphisms (SNP). Cost reduction can be achieved by imputing genotypes from lower to higher densities. Locally adapted breeds tend to be admixed and exhibit a high degree of genomic heterogeneity thus necessitating the optimization of SNP selection for downstream imputation. The aim of this study was to quantify the achievable imputation accuracy for a sample of 1,135 South African (SA) Drakensberger using several custom-derived lower-density panels varying in both SNP density and how the SNP were selected. From a pool of 120,608 genotyped SNP, subsets of SNP were chosen 1) at random, 2) with even genomic dispersion, 3) by maximizing the mean minor allele frequency (MAF), 4) using a combined score of MAF and linkage disequilibrium (LD), 5) using a partitioning-around-medoids (PAM) algorithm, and finally 6) using a hierarchical LD-based clustering algorithm. Imputation accuracy to higher density improved as SNP density increased; animal-wise imputation accuracy defined as the within-animal correlation between the imputed and actual alleles ranged from 0.625 to 0.990 when 2,500 randomly selected SNP were chosen versus a range of 0.918 to 0.999 when 50,000 randomly selected SNP were used. At a panel density of 10,000 SNP, the mean (standard deviation) animal-wise allele concordance rate was 0.976 (0.018) versus 0.982 (0.014) when the worst (i.e., random) as opposed to the best (i.e., combination of MAF and LD) SNP selection strategy was employed. A difference of 0.071 units was observed between the mean correlation-based accuracy of imputed SNP categorized as low (0.01<MAF≤0.1) versus high MAF (0.4<MAF≤0.5). Greater mean imputation accuracy was achieved for SNP located on autosomal extremes when these regions were populated with more SNP. The presented results suggested that genotype imputation can be a practical cost-saving strategy for indigenous breeds such as the South African Drakensberger. Based on the results, a genotyping panel consisting of approximately 10,000 SNP selected based on a combination of MAF and LD would suffice in achieving a less than 3% imputation error rate for a breed characterized by genomic admixture on the condition that these SNP are selected based on breed-specific selection criteria.

scholarly journals Genome Analysis of A Novel South African Cydia pomonella granulovirus (CpGV-SA) with Resistance-Breaking Potential

Viruses ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 658 ◽  
Author(s):  
Boitumelo Motsoeneng ◽  
Michael D. Jukes ◽  
Caroline M. Knox ◽  
Martin P. Hill ◽  
Sean D. Moore
Keyword(s):  
South African ◽  
Complete Genome ◽  
Cydia Pomonella ◽  
Codling Moth ◽  
Type I ◽  
Nucleotide Polymorphisms ◽  
Pome Fruit ◽  
Single Nucleotide ◽  
Resistance Breaking ◽  
Cydia Pomonella Granulovirus

The complete genome of an endemic South African Cydia pomonella granulovirus isolate was sequenced and analyzed. Several missing or truncated open reading frames (ORFs) were identified, including a 24 bp deletion in the pe38 gene which is reported to be associated with type I resistance-breaking potential. Comparison of single nucleotide polymorphisms (SNPs) with five other fully sequenced CpGV isolates identified 67 unique events, 47 of which occurred within ORFs, leading to several amino acid changes. Further analysis of single nucleotide variations (SNVs) within CpGV-SA revealed that this isolate consists of mixed genotypes. Phylogenetic analysis using complete genome sequences placed CpGV-SA basal to M, I12 and E2 and distal to S and I07 but with no distinct classification into any of the previously defined CpGV genogroups. These results suggest that CpGV-SA is a novel and genetically distinct isolate with significant potential as a biopesticide for management of codling moth (CM), not only in South Africa, but potentially in other pome fruit producing countries, particularly where CM resistance to CpGV has been reported.

scholarly journals A-to-I RNA Editing Uncovers Hidden Signals of Adaptive Genome Evolution in Animals

2020 ◽  
Vol 12 (4) ◽  
pp. 345-357 ◽  
Author(s):  
Niko Popitsch ◽  
Christian D Huber ◽  
Ilana Buchumenski ◽  
Eli Eisenberg ◽  
Michael Jantsch ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Single Nucleotide Polymorphisms ◽  
Genome Evolution ◽  
Rna Editing ◽  
Adaptive Evolution ◽  
Population Genomics ◽  
Common Type ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Cellular Machinery

Abstract In animals, the most common type of RNA editing is the deamination of adenosines (A) into inosines (I). Because inosines basepair with cytosines (C), they are interpreted as guanosines (G) by the cellular machinery and genomically encoded G alleles at edited sites mimic the function of edited RNAs. The contribution of this hardwiring effect on genome evolution remains obscure. We looked for population genomics signatures of adaptive evolution associated with A-to-I RNA edited sites in humans and Drosophila melanogaster. We found that single nucleotide polymorphisms at edited sites occur 3 (humans) to 15 times (Drosophila) more often than at unedited sites, the nucleotide G is virtually the unique alternative allele at edited sites and G alleles segregate at higher frequency at edited sites than at unedited sites. Our study reveals that a significant fraction of coding synonymous and nonsynonymous as well as silent and intergenic A-to-I RNA editing sites are likely adaptive in the distantly related human and Drosophila lineages.

scholarly journals Transposable elements contribute to the genomic response to insecticides in Drosophila melanogaster

2020 ◽  
Vol 375 (1795) ◽  
pp. 20190341 ◽  
Author(s):  
Judit Salces-Ortiz ◽  
Carlos Vargas-Chavez ◽  
Lain Guio ◽  
Gabriel E. Rech ◽  
Josefa González
Keyword(s):  
Gene Expression ◽  
Drosophila Melanogaster ◽  
Regulatory Networks ◽  
Regulation Of Gene Expression ◽  
Nucleotide Polymorphisms ◽  
Rna Seq ◽  
Organophosphate Insecticide ◽  
Single Nucleotide ◽  
Insecticide Exposure ◽  
Genomic Response

Most of the genotype–phenotype analyses to date have largely centred attention on single nucleotide polymorphisms. However, transposable element (TE) insertions have arisen as a plausible addition to the study of the genotypic–phenotypic link because of to their role in genome function and evolution. In this work, we investigate the contribution of TE insertions to the regulation of gene expression in response to insecticides. We exposed four Drosophila melanogaster strains to malathion, a commonly used organophosphate insecticide. By combining information from different approaches, including RNA-seq and ATAC-seq, we found that TEs can contribute to the regulation of gene expression under insecticide exposure by rewiring cis -regulatory networks. This article is part of a discussion meeting issue ‘Crossroads between transposons and gene regulation’.

scholarly journals PXR and CAR single nucleotide polymorphisms influence plasma efavirenz levels in South African HIV/AIDS patients

2012 ◽  
Vol 13 (1) ◽  
Author(s):  
Marelize Swart ◽  
Heather Whitehorn ◽  
Yuan Ren ◽  
Peter Smith ◽  
Rajkumar S Ramesar ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
South African ◽  
Nucleotide Polymorphisms ◽  
Aids Patients ◽  
Single Nucleotide ◽  
Hiv Aids

SSCP Analysis of cDNA Markers Provides a Dense Linkage Map of theAedes aegyptiGenome

Genetics ◽  
2001 ◽  
Vol 158 (2) ◽  
pp. 715-726 ◽  
Author(s):  
Ruth E Fulton ◽  
Michael L Salasek ◽  
Nancy M DuTeau ◽  
William C Black
Keyword(s):  
Population Genetics ◽  
Drosophila Melanogaster ◽  
Linkage Map ◽  
Single Strand Conformation Polymorphism ◽  
Genome Project ◽  
Sscp Analysis ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
F2 Progeny ◽  
Conformation Polymorphism

AbstractAn intensive linkage map of the yellow fever mosquito, Aedes aegypti, was constructed using single-strand conformation polymorphism (SSCP) analysis of cDNA markers to identify single nucleotide polymorphisms (SNPs). A total of 94 A. aegypti cDNAs were downloaded from GenBank and primers were designed to amplify fragments <500 bp in size. These primer pairs amplified 94 loci, 57 (61%) of which segregated in a single F1 intercross family among 83 F2 progeny. This allowed us to produce a dense linkage map of one marker every 2 cM distributed over a total length of 134 cM. Many A. aegypti cDNAs were highly similar to genes in the Drosophila melanogaster genome project. Comparative linkage analysis revealed areas of synteny between the two species. SNP polymorphisms are abundant in A. aegypti genes and should prove useful in both population genetics and mapping studies.

scholarly journals Whole Genome Sequence Analysis of Brucella abortus Isolates from Various Regions of South Africa

2021 ◽  
Vol 9 (3) ◽  
pp. 570
Author(s):  
Maphuti Betty Ledwaba ◽  
Barbara Akorfa Glover ◽  
Itumeleng Matle ◽  
Giuseppe Profiti ◽  
Pier Luigi Martelli ◽  
...  
Keyword(s):  
South Africa ◽  
Single Nucleotide Polymorphisms ◽  
South African ◽  
Genome Sequence ◽  
Brucella Abortus ◽  
Whole Genome Sequence ◽  
Snp Analysis ◽  
Whole Genome ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide

The availability of whole genome sequences in public databases permits genome-wide comparative studies of various bacterial species. Whole genome sequence-single nucleotide polymorphisms (WGS-SNP) analysis has been used in recent studies and allows the discrimination of various Brucella species and strains. In the present study, 13 Brucella spp. strains from cattle of various locations in provinces of South Africa were typed and discriminated. WGS-SNP analysis indicated a maximum pairwise distance ranging from 4 to 77 single nucleotide polymorphisms (SNPs) between the South African Brucella abortus virulent field strains. Moreover, it was shown that the South African B. abortus strains grouped closely to B. abortus strains from Mozambique and Zimbabwe, as well as other Eurasian countries, such as Portugal and India. WGS-SNP analysis of South African B. abortus strains demonstrated that the same genotype circulated in one farm (Farm 1), whereas another farm (Farm 2) in the same province had two different genotypes. This indicated that brucellosis in South Africa spreads within the herd on some farms, whereas the introduction of infected animals is the mode of transmission on other farms. Three B. abortus vaccine S19 strains isolated from tissue and aborted material were identical, even though they originated from different herds and regions of South Africa. This might be due to the incorrect vaccination of animals older than the recommended age of 4–8 months or might be a problem associated with vaccine production.

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