scholarly journals Genetic Stability of Aedes aegypti Populations following Invasion by wMel Wolbachia

2021 ◽  
Author(s):  
Meng-Jia Lau ◽  
Tom Schmidt ◽  
Qiong Yang ◽  
Jessica Chung ◽  
Lucien Sankey ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Disease Transmission ◽  
Natural Populations ◽  
Geographic Location ◽  
Infection Status ◽  
Outlier Analysis ◽  
Genetic Changes ◽  
Genome Wide ◽  
And Behavior

Abstract BackgroundWolbachia wMel is the most used strain in mosquito rear and release strategies that aim to inhibit the transmission of arboviruses such as dengue, Zika, Chikungunya and yellow fever. However, the long-term establishment of wMel in natural populations of the dengue mosquito Aedes aegypti raises concerns that interactions between Wolbachia wMel and Ae. aegypti may lead to changes in the host genome, which could affect useful attributes of Wolbachia that allow it to invade and suppress disease transmission. ResultsWe applied an evolve-and-resequence approach to study genome-wide genetic changes in Ae. aegypti from the Cairns region, Australia, where Wolbachia wMel was first introduced more than 10 years ago. Mosquito samples were collected at three different time points in Gordonvale, Australia, covering the phase before (2010) and after (2013 and 2018) Wolbachia releases. An additional three locations where Wolbachia replacement happened at different times across the last decade were also sampled in 2018. We found that the genomes of mosquito populations mostly remained stable after Wolbachia release, with population differences tending to reflect the geographic location of the populations rather than Wolbachia infection status. However, outlier analysis suggests that Wolbachia may have had an influence on some genes related to immune response, development, recognition and behavior. ConclusionsAe. aegypti populations remained geographically distinct after Wolbachia wMel releases in North Australia despite their Wolbachia infection status. At some specific genomic loci, we found signs of selection associated with Wolbachia, suggesting potential evolutionary impacts can happen in the future and further monitoring is warranted.

scholarly journals Genetic stability of Aedes aegypti populations following invasion by wMel Wolbachia

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Meng-Jia Lau ◽  
Thomas L. Schmidt ◽  
Qiong Yang ◽  
Jessica Chung ◽  
Lucien Sankey ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Disease Transmission ◽  
Geographic Location ◽  
Infection Status ◽  
Population Differences ◽  
Outlier Analysis ◽  
Genetic Changes ◽  
Genome Wide ◽  
And Behavior

Abstract Background Wolbachia wMel is the most commonly used strain in rear and release strategies for Aedes aegypti mosquitoes that aim to inhibit the transmission of arboviruses such as dengue, Zika, Chikungunya and yellow fever. However, the long-term establishment of wMel in natural Ae. aegypti populations raises concerns that interactions between Wolbachia wMel and Ae. aegypti may lead to changes in the host genome, which could affect useful attributes of Wolbachia that allow it to invade and suppress disease transmission. Results We applied an evolve-and-resequence approach to study genome-wide genetic changes in Ae. aegypti from the Cairns region, Australia, where Wolbachia wMel was first introduced more than 10 years ago. Mosquito samples were collected at three different time points in Gordonvale, Australia, covering the phase before (2010) and after (2013 and 2018) Wolbachia releases. An additional three locations where Wolbachia replacement happened at different times across the last decade were also sampled in 2018. We found that the genomes of mosquito populations mostly remained stable after Wolbachia release, with population differences tending to reflect the geographic location of the populations rather than Wolbachia infection status. However, outlier analysis suggests that Wolbachia may have had an influence on some genes related to immune response, development, recognition and behavior. Conclusions Ae. aegypti populations remained geographically distinct after Wolbachia wMel releases in North Australia despite their Wolbachia infection status. At some specific genomic loci, we found signs of selection associated with Wolbachia, suggesting potential evolutionary impacts can happen in the future and further monitoring is warranted.

scholarly journals Genetic stability of Aedes aegypti populations following invasion by wMel Wolbachia

2021 ◽  
Author(s):  
Meng-Jia Lau ◽  
Tom Schmidt ◽  
Qiong Yang ◽  
Jessica Chung ◽  
Ary A. Hoffmann
Keyword(s):  
Aedes Aegypti ◽  
Disease Transmission ◽  
Natural Populations ◽  
Geographic Location ◽  
Infection Status ◽  
Population Differences ◽  
Outlier Analysis ◽  
Genetic Changes ◽  
Genome Wide

Background: Wolbachia wMel play a major role in mosquito rear and release strategies that aim to inhibit the transmission of arboviruses such as dengue, Zika, Chikungunya and yellow fever. However, the long-term establishment of wMel in natural populations of the dengue mosquito Aedes aegypti raises concerns that interactions between Wolbachia wMel and Ae. aegypti may lead to changes in the host genome, which could affect useful attributes of Wolbachia that allow it to invade and suppress disease transmission. Results: We applied an evolve-and-resequence approach to study genome-wide genetic changes in Ae. aegypti from the Cairns region, Australia, where Wolbachia wMel was first introduced more than 10 years ago. Mosquito samples were collected at three different time points in Gordonvale, Australia, covering the phase before (2010) and after (2013 and 2018) Wolbachia releases; an additional three locations where Wolbachia replacement happened at different times across the last decade were also sampled in 2018. We found that in general, the genome of mosquito populations mostly remained stable after Wolbachia release, with any population differences tending to reflect the geographic location of the populations rather than Wolbachia infection status. Whereas on the other hand, outlier analysis suggested that Wolbachia may have had an influence on some genes related to immune response, development, recognition and behaviour. Conclusions: In general, Ae. aegypti populations remained geographically distinct after Wolbachia releases in North Australia despite their Wolbachia infection status. Whereas at some specific genomic loci, we found signs of selection associated with Wolbachia, suggesting potential evolutionary impacts can happen in the future and further monitoring is warranted.

scholarly journals Spatio-temporal ecological and evolutionary dynamics in natural butterfly populations

2017 ◽  
Vol 40 ◽  
pp. 31-36
Author(s):  
Zachariah Gompert ◽  
Lauren Lucas
Keyword(s):  
Evolutionary Dynamics ◽  
Natural Populations ◽  
Distance Sampling ◽  
Spatial And Temporal Variation ◽  
Insect Community ◽  
Long Term Study ◽  
Greater Yellowstone Area ◽  
Genome Wide ◽  
Spatio Temporal

Long term studies of wild populations indicate that natural selection can cause rapid and dramatic changes in traits, with spatial and temporal variation in the strength of selection a critical driver of genetic variation in natural populations. In 2012, we began a long term study of genome-wide molecular evolution in populations of the butterfly Lycaeides ideas in the Greater Yellowstone Area (GYA). We aimed to quantify the role of environment-dependent selection on evolution in these populations. Building on previous work, in 2017 we collected new samples, incorporated distance sampling, and surveyed the insect community at each site. We also defined the habitat boundary at anew, eleventh site. Our preliminary analyses suggest that both genetic drift and selection are important drivers in this system.   Featured photo from Figure 1 in report.

scholarly journals A complex multi-locus, multi-allelic genetic architecture underlying the long-term selection-response in the Virginia body weight line of chickens

2017 ◽  
Author(s):  
Yanjun Zan ◽  
Zheya Sheng ◽  
Lars Rönnegård ◽  
Christa F. Honaker ◽  
Paul B. Siegel ◽  
...  
Keyword(s):  
Body Weight ◽  
Additive Genetic Variance ◽  
Natural Populations ◽  
Selection Response ◽  
Multiple Alleles ◽  
Term Selection ◽  
Selection Responses ◽  
Genome Wide ◽  
Genetic Mechanisms

AbstractThe ability of a population to adapt to changes in their living conditions, whether in nature or captivity, often depends on polymorphisms in multiple genes across the genome. In-depth studies of such polygenic adaptations are difficult in natural populations, but can be approached using the resources provided by artificial selection experiments. Here, we dissect the genetic mechanisms involved in long-term selection responses of the Virginia chicken lines, populations that after 40 generations of divergent selection for 56-day body weight display a nine-fold difference in the selected trait. In the F15 generation of an intercross between the divergent lines, 20 loci explained more than 60% of the additive genetic variance for the selected trait. We focused particularly on seven major QTL and found that only two fine-mapped to single, bi-allelic loci; the other five contained linked loci, multiple alleles or were epistatic. This detailed dissection of the polygenic adaptations in the Virginia lines provides a deeper understanding of genome-wide mechanisms involved in the long-term selection responses. The results illustrate that long-term selection responses, even from populations with a limited genetic diversity, can be polygenic and influenced by a range of genetic mechanisms.

scholarly journals A w AlbB Wolbachia transinfection displays stable phenotypic effects across divergent Aedes aegypti mosquito backgrounds

2021 ◽  
Author(s):  
Perran A. Ross ◽  
Xinyue Gu ◽  
Katie L. Robinson ◽  
Qiong Yang ◽  
Ellen Cottingham ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Cytoplasmic Incompatibility ◽  
Mosquito Control ◽  
Host Genotype ◽  
Egg Hatch ◽  
Genetic Changes ◽  
Control Programs ◽  
Nuclear Background ◽  
The Stability

Aedes mosquitoes harboring intracellular Wolbachia bacteria are being released in arbovirus and mosquito control programs. With releases taking place around the world, understanding the contribution of host variation to Wolbachia phenotype is crucial. We generated a Wolbachia transinfection ( w AlbB Q ) in Aedes aegypti and performed backcrossing to introduce the infection into Australian or Malaysian nuclear backgrounds. Whole Wolbachia genome sequencing shows that the w AlbB Q transinfection is near-identical to the reference w AlbB genome, suggesting few changes since the infection was first introduced to Ae. aegypti over 15 years ago. However, these sequences were distinct from other available w AlbB genome sequences, highlighting the potential diversity of w AlbB in natural Ae. albopictus populations. Phenotypic comparisons demonstrate effects of w AlbB infection on egg hatch and nuclear background on fecundity and body size, but no interactions between w AlbB infection and nuclear background for any trait. The w AlbB infection was stable at high temperatures and showed perfect maternal transmission and cytoplasmic incompatibility regardless of host background. Our results demonstrate the stability of w AlbB across host backgrounds and point to its long-term effectiveness for controlling arbovirus transmission and mosquito populations. Importance Wolbachia bacteria are being used to control the transmission of dengue and other arboviruses by mosquitoes. For Wolbachia release programs to be effective globally, Wolbachia infections must be stable across mosquito populations from different locations. In this study, we transferred Wolbachia (strain w AlbB) to Aedes aegypti mosquitoes with an Australian genotype and introduced the infection to Malaysian mosquitoes through backcrossing. We found that the phenotypic effects of Wolbachia are stable across both mosquito backgrounds. We sequenced the genome of w AlbB and found very few genetic changes despite spending over 15 years in a novel mosquito host. Our results suggest that the effects of Wolbachia infections are likely to remain stable across time and host genotype.

scholarly journals Genome-enabled discovery of evolutionary divergence in brains and behavior

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chinar Patil ◽  
Jonathan B. Sylvester ◽  
Kawther Abdilleh ◽  
Michael W. Norsworthy ◽  
Karen Pottin ◽  
...  
Keyword(s):  
Reverse Genetics ◽  
Natural Populations ◽  
Bmp Signaling ◽  
Evolutionary Divergence ◽  
Genetic Changes ◽  
Form And Function ◽  
Brain Gene Expression ◽  
Evolutionarily Conserved ◽  
And Function ◽  
And Behavior

AbstractLake Malawi cichlid fishes exhibit extensive divergence in form and function built from a relatively small number of genetic changes. We compared the genomes of rock- and sand-dwelling species and asked which genetic variants differed among the groups. We found that 96% of differentiated variants reside in non-coding sequence but these non-coding diverged variants are evolutionarily conserved. Genome regions near differentiated variants are enriched for craniofacial, neural and behavioral categories. Following leads from genome sequence, we used rock- vs. sand-species and their hybrids to (i) delineate the push–pull roles of BMP signaling and irx1b in the specification of forebrain territories during gastrulation and (ii) reveal striking context-dependent brain gene expression during adult social behavior. Our results demonstrate how divergent genome sequences can predict differences in key evolutionary traits. We highlight the promise of evolutionary reverse genetics—the inference of phenotypic divergence from unbiased genome sequencing and then empirical validation in natural populations.

scholarly journals Genetic effects of long-term captive breeding on the endangered pygmy hog

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12212
Author(s):  
Deepanwita Purohit ◽  
Shivakumara Manu ◽  
Muthuvarmadam Subramanian Ram ◽  
Shradha Sharma ◽  
Harika Chinchilam Patnaik ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Captive Breeding ◽  
Mitochondrial Genomes ◽  
Captive Population ◽  
Genetic Changes ◽  
Captive Populations ◽  
Genome Wide ◽  
Pygmy Hog ◽  
Conservation Breeding

Long-term captive populations often accumulate genetic changes that are detrimental to their survival in the wild. Periodic genetic evaluation of captive populations is thus necessary to identify deleterious changes and minimize their impact through planned breeding. Pygmy hog (Porcula salvania) is an endangered species with a small population inhabiting the tall sub-Himalayan grasslands of Assam, India. A conservation breeding program of pygmy hog from six founders has produced a multi-generational captive population destined for reintroduction into the wild. However, the impact of conservation breeding on its genetic diversity remained undocumented. Here, we evaluate temporal genetic changes in 39 pygmy hogs from eight consecutive generations of a captive population using genome-wide SNPs, mitochondrial genomes, and MHC sequences, and explore the relationship between genetic diversity and reproductive success. We find that pygmy hog harbors a very low genome-wide heterozygosity (H) compared to other members of the Suidae family. However, within the captive population we find excess heterozygosity and a significant increase in H from the wild-caught founders to the individuals in subsequent generations due to the selective pairing strategy. The MHC and mitochondrial nucleotide diversities were lower in captive generations compared to the founders with a high prevalence of low-frequency MHC haplotypes and more unique mitochondrial genomes. Further, even though no signs of genetic inbreeding were observed from the estimates of individual inbreeding coefficient F and between individuals (FIS) in each generation, the kinship coefficient showed a slightly increasing trend in the recent generations, due to a relatively smaller non-random sample size compared to the entire captive population. Surprisingly, male pygmy hogs that had higher heterozygosity also showed lower breeding success. We briefly discuss the implications of our findings in the context of breeding management and recommend steps to minimize the genetic effects of long-term captive breeding.

scholarly journals Spatio-Temporal Ecological and Evolutionary Dynamics in Natural Butterfly Populations (2015 Field Season)

2015 ◽  
Vol 38 ◽  
pp. 29-32
Author(s):  
Zachariah Gompert ◽  
Lauren Lucas
Keyword(s):  
Genetic Variation ◽  
Natural Selection ◽  
Molecular Evolution ◽  
Natural Populations ◽  
Spatial And Temporal Variation ◽  
Long Term Study ◽  
Genome Wide ◽  
In The Wild ◽  
Long Term Studies

The study of evolution in natural populations has advanced our understanding of the origin and maintenance of biological diversity. For example, long term studies of wild populations indicate that natural selection can cause rapid and dramatic changes in traits, but that in some cases these evolutionary changes are quickly reversed when periodic variation in weather patterns or the biotic environment cause the optimal trait value to change (e.g., Reznick et al. 1997, Grant and Grant 2002). In fact, spatial and temporal variation in the strength and nature of natural selection could explain the high levels of genetic variation found in many natural populations (Gillespie 1994, Siepielski et al. 2009). Long term studies of evolution in the wild could also be informative for biodiversity conservation and resource management, because, for example, data on short term evolutionary responses to annual fluctuations in temperature or rainfall could be used to predict longer term evolution in response to directional climate change. Most previous research on evolution in the wild has considered one or a few observable traits or genes (e.g., Kapan 2001, Grant and Grant 2002, Barrett et al. 2008). We believe that more general conclusions regarding the rate and causes of evolutionary change in the wild and selection’s contribution to the maintenance of genetic variation could be obtained by studying genome-wide molecular evolution in a suite of natural populations. Thus, in 2012 we began a long term study of genome-wide molecular evolution in a series of natural butterfly populations in the Greater Yellowstone Area (GYA). This study will allow us to quantify the contribution of environment-dependent natural selection to evolution in these butterfly populations and determine whether selection consistently favors the same alleles across space and through time.

scholarly journals Spatio-Temporal Evolutionary Dynamics in Natural Butterfly Populations (2012 Field Season)

2012 ◽  
Vol 35 ◽  
pp. 73-76
Author(s):  
Zachariah Gompert ◽  
Lauren Lucas
Keyword(s):  
Genetic Variation ◽  
Natural Selection ◽  
Molecular Evolution ◽  
Natural Populations ◽  
Spatial And Temporal Variation ◽  
Long Term Study ◽  
Genome Wide ◽  
In The Wild ◽  
Long Term Studies

The study of evolution in natural populations has advanced our understanding of the origin and maintenance of biological diversity. For example, long term studies of wild populations indicate that natural selection can cause rapid and dramatic changes in traits, but that in some cases these evolutionary changes are quickly reversed when periodic variation in weather patterns or the biotic environment cause the optimal trait value to change (e.g., Reznick et al. 1997; Grant and Grant 2002). In fact, spatial and temporal variation in the strength and nature of natural selection could explain the high levels of genetic variation found in many natural populations (Gillespie 1994; Siepielski et al. 2009). Long term studies of evolution in the wild could also be informative for biodiversity conservation and resource management, because, for example, data on short term evolutionary responses to annual fluctuations in temperature or rainfall could be used to predict longer term evolution in response to directional climate change. Most previous research on evolution in the wild has considered one or a few observable traits or genes (Kapan 2001; Grant and Grant 2002; Barrett et al. 2008). We believe that more general conclusions regarding the rate and causes of evolutionary change in the wild and selection’s contribution to the maintenance of genetic variation could be obtained by studying genome-wide molecular evolution in a suite of natural populations. Thus, we have begun a long term study of genome-wide molecular evolution in a series of natural butterfly populations in the Greater Yellowstone Area (GYA). This study will allow us to quantify the contribution of environment-dependent natural selection to evolution in these butterfly populations and determine whether selection consistently favors the same alleles across space and through time.

scholarly journals Reduced competence to arboviruses following the sustainable invasion of Wolbachia into native Aedes aegypti from Southeastern Brazil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
João Silveira Moledo Gesto ◽  
Gabriel Sylvestre Ribeiro ◽  
Marcele Neves Rocha ◽  
Fernando Braga Stehling Dias ◽  
Julia Peixoto ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Disease Transmission ◽  
Oral Feeding ◽  
Southeastern Brazil ◽  
Proof Of Concept ◽  
Small Community ◽  
High Infection ◽  
Promising Solution ◽  
Virus Blocking

AbstractField release of Wolbachia-infected Aedes aegypti has emerged as a promising solution to manage the transmission of dengue, Zika and chikungunya in endemic areas across the globe. Through an efficient self-dispersing mechanism, and the ability to induce virus-blocking properties, Wolbachia offers an unmatched potential to gradually modify wild Ae. aegypti populations turning them unsuitable disease vectors. Here we describe a proof-of-concept field trial carried out in a small community of Niterói, greater Rio de Janeiro, Brazil. Following the release of Wolbachia-infected eggs, we report here a successful invasion and long-term establishment of the bacterium across the territory, as denoted by stable high-infection indexes (> 80%). We have also demonstrated that refractoriness to dengue and Zika viruses, either thorough oral-feeding or intra-thoracic saliva challenging assays, was maintained over the adaptation to the natural environment of Southeastern Brazil. These findings further support Wolbachia’s ability to invade local Ae. aegypti populations and impair disease transmission, and will pave the way for future epidemiological and economic impact assessments.

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