scholarly journals Restriction to gene flow is associated with changes in the molecular basis of pyrethroid resistance in the malaria vector Anopheles funestus

2016 ◽  
Vol 114 (2) ◽  
pp. 286-291 ◽  
Author(s):  
Kayla G. Barnes ◽  
Helen Irving ◽  
Martin Chiumia ◽  
Themba Mzilahowa ◽  
Michael Coleman ◽  
...  

Resistance to pyrethroids, the sole insecticide class recommended for treating bed nets, threatens the control of major malaria vectors, including Anopheles funestus. Effective management of resistance requires an understanding of the dynamics and mechanisms driving resistance. Here, using genome-wide transcription and genetic diversity analyses, we show that a shift in the molecular basis of pyrethroid resistance in southern African populations of this species is associated with a restricted gene flow. Across the most highly endemic and densely populated regions in Malawi, An. funestus is resistant to pyrethroids, carbamates, and organochlorides. Genome-wide microarray-based transcription analysis identified overexpression of cytochrome P450 genes as the main mechanism driving this resistance. The most up-regulated genes include cytochrome P450s (CYP) CYP6P9a, CYP6P9b and CYP6M7. However, a significant shift in the overexpression profile of these genes was detected across a south/north transect, with CYP6P9a and CYP6P9b more highly overexpressed in the southern resistance front and CYP6M7 predominant in the northern front. A genome-wide genetic structure analysis of southern African populations of An. funestus from Zambia, Malawi, and Mozambique revealed a restriction of gene flow between populations, in line with the geographical variation observed in the transcriptomic analysis. Genetic polymorphism analysis of the three key resistance genes, CYP6P9a, CYP6P9b, and CYP6M7, support barriers to gene flow that are shaping the underlying molecular basis of pyrethroid resistance across southern Africa. This barrier to gene flow is likely to impact the design and implementation of resistance management strategies in the region.

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0240743
Author(s):  
Maurice Marcel Sandeu ◽  
Charles Mulamba ◽  
Gareth D. Weedall ◽  
Charles S. Wondji

Background Insecticide resistance is challenging the effectiveness of insecticide-based control interventions to reduce malaria burden in Africa. Understanding the molecular basis of insecticides resistance and patterns of gene flow in major malaria vectors such as Anopheles funestus are important steps for designing effective resistance management strategies. Here, we investigated the association between patterns of genetic structure and expression profiles of genes involved in the pyrethroid resistance in An. funestus across Uganda and neighboring Kenya. Methods Blood-fed mosquitoes An. funestus were collected across the four localities in Uganda and neighboring Kenya. A Microarray-based genome-wide transcription analysis was performed to identify the set of genes associated with permethrin resistance. 17 microsatellites markers were genotyped and used to establish patterns of genetic differentiation. Results Microarray-based genome-wide transcription profiling of pyrethroid resistance in four locations across Uganda (Arua, Bulambuli, Lira, and Tororo) and Kenya (Kisumu) revealed that resistance was mainly driven by metabolic resistance. The most commonly up-regulated genes in pyrethroid resistance mosquitoes include cytochrome P450s (CYP9K1, CYP6M7, CYP4H18, CYP4H17, CYP4C36). However, expression levels of key genes vary geographically such as the P450 CYP6M7 [Fold-change (FC) = 115.8 (Arua) vs 24.05 (Tororo) and 16.9 (Kisumu)]. In addition, several genes from other families were also over-expressed including Glutathione S-transferases (GSTs), carboxylesterases, trypsin, glycogenin, and nucleotide binding protein which probably contribute to insecticide resistance across Uganda and Kenya. Genotyping of 17 microsatellite loci in the five locations provided evidence that a geographical shift in the resistance mechanisms could be associated with patterns of population structure throughout East Africa. Genetic and population structure analyses indicated significant genetic differentiation between Arua and other localities (FST>0.03) and revealed a barrier to gene flow between Arua and other areas, possibly associated with Rift Valley. Conclusion The correlation between patterns of genetic structure and variation in gene expression could be used to inform future interventions especially as new insecticides are gradually introduced.


Blood ◽  
2008 ◽  
Vol 112 (7) ◽  
pp. 2709-2712 ◽  
Author(s):  
Maria E. Sarasquete ◽  
Ramon García-Sanz ◽  
Luis Marín ◽  
Miguel Alcoceba ◽  
Maria C. Chillón ◽  
...  

Abstract We have explored the potential role of genetics in the development of osteonecrosis of the jaw (ONJ) in multiple myeloma (MM) patients under bisphosphonate therapy. A genome-wide association study was performed using 500 568 single nucleotide polymorphisms (SNPs) in 2 series of homogeneously treated MM patients, one with ONJ (22 MM cases) and another without ONJ (65 matched MM controls). Four SNPs (rs1934951, rs1934980, rs1341162, and rs17110453) mapped within the cytochrome P450-2C gene (CYP2C8) showed a different distribution between cases and controls with statistically significant differences (P = 1.07 × 10−6, P = 4.231 × 10−6, P = 6.22 × 10−6, and P = 2.15 × 10−6, respectively). SNP rs1934951 was significantly associated with a higher risk of ONJ development even after Bonferroni correction (P corrected value = .02). Genotyping results displayed an overrepresentation of the T allele in cases compared with controls (48% vs 12%). Thus, individuals homozygous for the T allele had an increased likelihood of developing ONJ (odds ratio 12.75, 95% confidence interval 3.7-43.5).


2021 ◽  
Vol 13 (1S) ◽  
pp. 31-38
Author(s):  
Ya. R. Timasheva ◽  
T. R. Nasibullin ◽  
I. A. Tuktarova ◽  
V. V. Erdman ◽  
T. R. Galiullin ◽  
...  

Objective: to perform a genome-wide polygenic analysis of multiple sclerosis (MS) markers in the ethnic groups of Bashkirs, Russians, and Tatars living in the Republic of Bashkortostan (Russian Federation).Patients and methods. Genotyping was performed using allele-specific polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism analysis of genes of the human leukocyte differentiation antigens CD6 (rs17824933), CD40 (rs6074022), CD58 (rs2300747), CD86 (rs9282641), transcription factors SOX8 (rs2744148) and ZBTB46 (rs6062314), beta-mannosidase MANBA (rs228614), C-type lectin domain CLEC16A (rs12708716), ribosomal protein S6 kinase B1 RPS6KB1 (rs180515), and long noncoding RNA gene PVT1 (rs759648) in 644 patients with MS and 1408 controls. Multilocus analysis of the disease associations with combinations of genotypes and alleles of the studied polymorphic loci was performed using the APSampler algorithm.Results and discussion. We determined the distribution of genotype and allele frequencies of the studied polymorphic loci in the ethnic groups of Bashkirs, Russians, and Tatars. We also observed disease associations with CD58 (rs2300747) and RPS6KB1 (rs180515) polymorphic loci in Russian men, CD86 (rs9282641) in Russian, PVT1 (rs759648) in Tatar women, CD40 (rs6074022) in Bashkir men, and identified 19 combinations of genotypes and/or alleles significantly associated with MS.Conclusion. Based on the genome-wide polygenic analysis of MS markers, we identified ethno- and gender-specific combined markers of the disease susceptibility.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
George BJ Busby ◽  
Gavin Band ◽  
Quang Si Le ◽  
Muminatou Jallow ◽  
Edith Bougama ◽  
...  

Similarity between two individuals in the combination of genetic markers along their chromosomes indicates shared ancestry and can be used to identify historical connections between different population groups due to admixture. We use a genome-wide, haplotype-based, analysis to characterise the structure of genetic diversity and gene-flow in a collection of 48 sub-Saharan African groups. We show that coastal populations experienced an influx of Eurasian haplotypes over the last 7000 years, and that Eastern and Southern Niger-Congo speaking groups share ancestry with Central West Africans as a result of recent population expansions. In fact, most sub-Saharan populations share ancestry with groups from outside of their current geographic region as a result of gene-flow within the last 4000 years. Our in-depth analysis provides insight into haplotype sharing across different ethno-linguistic groups and the recent movement of alleles into new environments, both of which are relevant to studies of genetic epidemiology.


2019 ◽  
Vol 110 (3) ◽  
pp. 361-369 ◽  
Author(s):  
Katherine L Bell ◽  
Chris C Nice ◽  
Darrin Hulsey

Abstract In recent decades, an increased understanding of molecular ecology has led to a reinterpretation of the role of gene flow during the evolution of reproductive isolation and biological novelty. For example, even in the face of ongoing gene flow strong selection may maintain divergent polymorphisms, or gene flow may introduce novel biological diversity via hybridization and introgression from a divergent species. Herein, we elucidate the evolutionary history and genomic basis of a trophically polymorphic trait in a species of cichlid fish, Herichthys minckleyi. We explored genetic variation at 3 hierarchical levels; between H. minckleyi (n = 69) and a closely related species Herichthys cyanoguttatus (n = 10), between H. minckleyi individuals from 2 geographic locations, and finally between individuals with alternate morphotypes at both a genome-wide and locus-specific scale. We found limited support for the hypothesis that the H. minckleyi polymorphism is the result of ongoing hybridization between the 2 species. Within H. minckleyi we found evidence of geographic genetic structure, and using traditional population genetic analyses found that individuals of alternate morphotypes within a pool appear to be panmictic. However, when we used a locus-specific approach to examine the relationship between multi-locus genotype, tooth size, and geographic sampling, we found the first evidence for molecular genetic differences between the H. minckleyi morphotypes.


2019 ◽  
Author(s):  
Linda Ongaro ◽  
Marilia O. Scliar ◽  
Rodrigo Flores ◽  
Alessandro Raveane ◽  
Davide Marnetto ◽  
...  

AbstractThe human genetic diversity of the Americas has been shaped by several events of gene flow that have continued since the Colonial Era and the Atlantic slave trade. Moreover, multiple waves of migration followed by local admixture occurred in the last two centuries, the impact of which has been largely unexplored.Here we compiled a genome-wide dataset of ∼12,000 individuals from twelve American countries and ∼6,000 individuals from worldwide populations and applied haplotype-based methods to investigate how historical movements from outside the New World affected i) the genetic structure, ii) the admixture profile, iii) the demographic history and iv) sex-biased gene-flow dynamics, of the Americas.We revealed a high degree of complexity underlying the genetic contribution of European and African populations in North and South America, from both geographic and temporal perspectives, identifying previously unreported sources related to Italy, the Middle East and to specific regions of Africa.


2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Yanlin Cao ◽  
Yenan Zhan ◽  
Sujun Qiu ◽  
Zhong Chen ◽  
Kaiqin Gong ◽  
...  

Abstract Background Hypertrophy of ligamentum flavum (HLF) is a common lumbar degeneration disease (LDD) with typical symptoms of low back pain and limb numbness owing to an abnormal pressure on spinal nerves. Previous studies revealed HLF might be caused by fibrosis, inflammatory, and other bio-pathways. However, a global analysis of HLF is needed severely. Methods A genome-wide DNA methylation and single-nucleotide polymorphism analysis were performed from five LDD patients with HLF and five LDD patients without HLF. Comprehensive integrated analysis was performed using bioinformatics analysis and the validated experiments including Sanger sequencing, methylation-specific PCR, qPCR and ROC analysis. Furthermore, the function of novel genes in ligamentum flavum cells (LFCs) was detected to explore the molecular mechanism in HLF through knock down experiment, overexpression experiment, CCK8 assay, apoptosis assay, and so on. Results We identified 69 SNP genes and 735 661 differentially methylated sites that were enriched in extracellular matrix, inflammatory, and cell proliferation. A comprehensive analysis demonstrated key genes in regulating the development of HLF including ACSM5. Furthermore, the hypermethylation of ACSM5 that was mediated by DNMT1 led to downregulation of ACSM5 expression, promoted the proliferation and fibrosis, and inhibited the apoptosis of LFCs. Conclusion This study revealed that DNMT1/ACSM5 signaling could enhance HLF properties in vitro as a potential therapeutic strategy for HLF.


2021 ◽  
Author(s):  
Gen Pan ◽  
Zheng Li ◽  
Siqi Huang ◽  
Jie Tao ◽  
Yaliang Shi ◽  
...  

Abstract Background: Cannabis sativa L., a dioecious plant, derived from China, demonstrates important medicinal properties and economic value worldwide. Cannabis properties were usually harnessed depending on the sex of the plant. To analyze the genetic structure of Chinese cannabis and identify sex-linked makers, the genome-wide insertion-deletion (InDel) markers were designed and used. Results: In this study, a genome-wide analysis of insertion–deletion (InDel) polymorphisms was performed based on the recent genome sequences. In total, 47558 InDels were detected between the two varieties, and the length of InDels ranged from 4 bp to 87 bp. The most common InDels were tetranucleotides, followed by pentanucleotides. Chromosome 5 had the highest number of InDels among the cannabis chromosomes, while chromosome 10 had the lowest number. Additionally, a total of 47558 InDel markers were designed, and 84 primers evenly distributed in the cannabis genome were chosen for polymorphism analysis. A total of 38 primers exhibited polymorphisms among three accessions, and of the polymorphism primers, 14 biallelic primers were further used to analyse the genetic structure. A total of 39 fragments were detected, and the PIC value ranged from 0.1209 to 0.6351. According to the Indel markers as well as the flowering time, the 115 Chinese germplasms were divided in two subgroups, which were mainly composed of cultivars from the most north and south regions, respectively. Additional, the marker “ I1-10” was found to amplify two bands (398bp and 251bp) in the male plants, while a 389bp bands in female plants. Using this marker, the feminized and dioecious varieties can also be distinguished.Conclusion: This study will facilitate the genetic improvement and germplasm conservation of cannabis in China, and the sex-linked InDel markers will provide accurate sex identification strategies for cannabis breeding and production.


Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1314
Author(s):  
Delia Doreen Djuicy ◽  
Jack Hearn ◽  
Magellan Tchouakui ◽  
Murielle J. Wondji ◽  
Helen Irving ◽  
...  

Pyrethroid resistance in major malaria vectors such as Anopheles funestus threatens malaria control efforts in Africa. Cytochrome P450-mediated metabolic resistance is best understood for CYP6P9 genes in southern Africa in An. funestus. However, we do not know if this resistance mechanism is spreading across Africa and how it relates to broader patterns of gene flow across the continent. Nucleotide diversity of the CYP6P9a gene and the diversity pattern of five gene fragments spanning a region of 120 kb around the CYP6P9a gene were surveyed in mosquitoes from southern, eastern and central Africa. These analyses revealed that a Cyp6P9a resistance-associated allele has swept through southern and eastern Africa and is now fixed in these regions. A similar diversity profile was observed when analysing genomic regions located 34 kb upstream to 86 kb downstream of the CYP6P9a locus, concordant with a selective sweep throughout the rp1 locus. We identify reduced gene flow between southern/eastern Africa and central Africa, which we hypothesise is due to the Great Rift Valley. These potential barriers to gene flow are likely to prevent or slow the spread of CYP6P9-based resistance mechanism to other parts of Africa and would to be considered in future vector control interventions such as gene drive.


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