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1.
BMC Genomics ; 25(1): 767, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39112925

RESUMO

Strong selection on complex traits can lead to skewed trait means and reduced trait variability in populations. An example of this phenomenon can be evidenced in allele frequency changes and skewed trait distributions driven by persistent human-directed selective pressures in domesticated species. Dog domestication is linked to several genomic variants; however, the functional impacts of these variants may not always be straightforward when found in non-coding regions of the genome. Four polymorphic transposable elements (TE) found within non-coding sites along a 5 Mb region on canine CFA6 have evolved due to directional selection associated with heightened human-directed hyper-sociability in domesticated dogs. We found that the polymorphic TE in intron 17 of the canine GTF2I gene, which was previously reported to be negatively correlated with canid human-directed hyper-sociability, is associated with altered chromatin looping and hence distinct cis-regulatory landscapes. We reported supporting evidence of an E2F1-DNA binding peak concordant with the altered loop and higher expression of GTF2I exon 18, indicative of alternative splicing. Globally, we discovered differences in pathways regulating the extra-cellular matrix with respect to TE copy number. Overall, we reported evidence suggesting an intriguing molecular convergence between the emergence of hypersocial behaviors in dogs and the same genes that, when hemizygous, produce human Williams Beuren Syndrome characterized by cranio-facial defects and heightened social behaviors. Our results additionally emphasize the often-overlooked potential role of chromatin architecture in social evolution.


Assuntos
Cromatina , Elementos de DNA Transponíveis , Cães , Animais , Cromatina/genética , Humanos , Comportamento Animal , Comportamento Social
2.
Mol Ecol ; 33(3): e17231, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38054561

RESUMO

Effective population size estimates are critical information needed for evolutionary predictions and conservation decisions. This is particularly true for species with social factors that restrict access to breeding or experience repeated fluctuations in population size across generations. We investigated the genomic estimates of effective population size along with diversity, subdivision, and inbreeding from 162,109 minimally filtered and 81,595 statistically neutral and unlinked SNPs genotyped in 437 grey wolf samples from North America collected between 1986 and 2021. We found genetic structure across North America, represented by three distinct demographic histories of western, central, and eastern regions of the continent. Further, grey wolves in the northern Rocky Mountains have lower genomic diversity than wolves of the western Great Lakes and have declined over time. Effective population size estimates revealed the historical signatures of continental efforts of predator extermination, despite a quarter century of recovery efforts. We are the first to provide molecular estimates of effective population size across distinct grey wolf populations in North America, which ranged between Ne ~ 275 and 3050 since early 1980s. We provide data that inform managers regarding the status and importance of effective population size estimates for grey wolf conservation, which are on average 5.2-9.3% of census estimates for this species. We show that while grey wolves fall above minimum effective population sizes needed to avoid extinction due to inbreeding depression in the short term, they are below sizes predicted to be necessary to avoid long-term risk of extinction.


Assuntos
Lobos , Animais , Lobos/genética , Genética Populacional , Genômica , Densidade Demográfica , América do Norte
3.
Behav Genet ; 54(2): 196-211, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38091228

RESUMO

A strong signature of selection in the domestic dog genome is found in a five-megabase region of chromosome six in which four structural variants derived from transposons have previously been associated with human-oriented social behavior, such as attentional bias to social stimuli and social interest in strangers. To explore these genetic associations in more phenotypic detail-as well as their role in training success in a specialized assistance dog program-we genotyped 1001 assistance dogs from Canine Companions for Independence®, including both successful graduates and dogs released from the training program for behaviors incompatible with their working role. We collected phenotypes on each dog using puppy-raiser questionnaires, trainer questionnaires, and both cognitive and behavioral tests. Using Bayesian mixed models, we found strong associations (95% credibility intervals excluding zero) between genotypes and certain behavioral measures, including separation-related problems, aggression when challenged or corrected, and reactivity to other dogs. Furthermore, we found moderate differences in the genotypes of dogs who graduated versus those who did not; insertions in GTF2I showed the strongest association with training success (ß = 0.23, CI95% = - 0.04, 0.49), translating to an odds-ratio of 1.25 for one insertion. Our results provide insight into the role of each of these four transposons in canine sociability and may inform breeding and training practices for working dog organizations. Furthermore, the observed importance of the gene GTF2I supports the emerging consensus that variation in GTF2I genotypes and expression have important consequences for social behavior broadly.


Assuntos
Fatores de Transcrição TFIII , Síndrome de Williams , Humanos , Cães , Animais , Animais de Trabalho , Síndrome de Williams/genética , Síndrome de Williams/psicologia , Comportamento Animal , Teorema de Bayes , Comportamento Social
4.
J Hered ; 115(4): 480-486, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38416051

RESUMO

Previous studies of canid population and evolutionary genetics have relied on high-quality domestic dog reference genomes that have been produced primarily for biomedical and trait mapping studies in dog breeds. However, the absence of highly contiguous genomes from other Canis species like the gray wolf and coyote, that represent additional distinct demographic histories, may bias inferences regarding interspecific genetic diversity and phylogenetic relationships. Here, we present single haplotype de novo genome assemblies for the gray wolf and coyote, generated by applying the trio-binning approach to long sequence reads generated from the genome of a female first-generation hybrid produced from a gray wolf and coyote mating. The assemblies were highly contiguous, with contig N50 sizes of 44.6 and 42.0 Mb for the wolf and coyote, respectively. Genome scaffolding and alignments between the two Canis assemblies and published dog reference genomes showed near complete collinearity, with one exception: a coyote-specific chromosome fission of chromosome 13 and fusion of the proximal portion of that chromosome with chromosome 8, retaining the Canis-typical haploid chromosome number of 2n = 78. We evaluated mapping quality for previous RADseq data from 334 canids and found nearly identical mapping quality and patterns among canid species and regional populations regardless of the genome used for alignment (dog, coyote, or gray wolf). These novel wolf and coyote genome reference assemblies will be important resources for proper and accurate inference of Canis demography, taxonomic evaluation, and conservation genetics.


Assuntos
Coiotes , Genoma , Genômica , Lobos , Animais , Coiotes/genética , Lobos/genética , Genômica/métodos , Feminino , Hibridização Genética , Filogenia , Cães/genética , Haplótipos , Mapeamento Cromossômico , Canidae/genética
5.
Mol Ecol ; 32(4): 892-903, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36435981

RESUMO

Ceruminous gland tumours are highly prevalent in the ear canals of Santa Catalina Island foxes (Urocyon littoralis catalinae). Previous work suggests that tumours may result from a combination of ectoparasites, disruption of the host-associated microbiome, and host immunopathology. More specifically, ear mite infection has been associated with broad-scale microbial dysbiosis marked by secondary bacterial infection with the opportunistic pathogen Staphylococcus pseudintermedius. Together, ear mites and S. pseudintermedius probably sustain chronic inflammation and promote conditions suitable for tumour development. In the present study, we expanded upon this framework by constructing otic microbial community networks for mite-infected and uninfected foxes sampled in 2017-2019. Across sampling years, we observed consistent signatures of microbial dysbiosis in mite-infected ear canals, including reduced microbial diversity and shifted abundance towards S. pseudintermedius. Network analysis further revealed that mite infection disrupts overall community structure. In mite-infected networks, interaction strengths between taxa were generally weaker, and numerous subnetworks disappeared altogether. We also found that two strains of S. pseudintermedius connected to the main network, suggesting that multistrain biofilm formation may be occurring. In contrast, S. pseudintermedius is peripheral in the uninfected network, with its only connections including a second strain of S. pseudintermedius and the possible competitor Acinetobacter rhizosphaerae. Finally, the lineup of potential keystone taxa shifted across disease states. Fusobacteria spp., a carcinogenesis-promoting microbe, assumed a keystone role in the mite-infected community. Considered together, these findings provide insights into how mite infection may destabilize the microbiome and ultimately contribute to tumour development in this island endemic species.


Assuntos
Microbiota , Ácaros , Animais , Raposas , Disbiose , Consórcios Microbianos
6.
J Hered ; 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37793153

RESUMO

For species of management concern, accurate estimates of inbreeding and associated consequences on reproduction are crucial for predicting their future viability. However, few studies have partitioned this aspect of genetic viability with respect to reproduction in a group-living social mammal. We investigated the contributions of foundation stock lineages, putative fitness consequences of inbreeding, and genetic diversity of the breeding versus non-reproductive segment of the Yellowstone National Park gray wolf population. Our dataset spans 25 years and seven generations since reintroduction, encompassing 152 nuclear families and 329 litters. We found over 87% of the pedigree foundation genomes persisted and report influxes of allelic diversity from two translocated wolves from a divergent source in Montana. As expected for group-living species, mean kinship significantly increased over time but with minimal loss of observed heterozygosity. Strikingly, the reproductive portion of the population carried a significantly lower genome-wide inbreeding coefficients, autozygosity, and more rapid decay for linkage disequilibrium relative to the non-breeding population. Breeding wolves had significantly longer lifespans and lower inbreeding coefficients than non-breeding wolves. Our model revealed that the number of litters was negatively significantly associated with heterozygosity (R=-0.11). Our findings highlight genetic contributions to fitness, and the importance of the reproductively active individuals in a population to counteract loss of genetic variation in a wild, free-ranging social carnivore. It is crucial for managers to mitigate factors that significantly reduce effective population size and genetic connectivity, which supports the dispersion of genetic variation that aids in rapid evolutionary responses to environmental challenges.

7.
Learn Behav ; 51(2): 131-134, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36810744

RESUMO

Here, we address Hansen Wheat et al.'s commentary in this journal in response to Salomons et al. Current Biology, 31(14), 3137-3144.E11, (2021). We conduct additional analyses in response to Hansen Wheat et al.'s two main questions. First, we examine the claim that it was the move to a human home environment which enabled the dog puppies to outperform the wolf puppies in gesture comprehension tasks. We show that the youngest dog puppies who had not yet been individually placed in raisers' homes were still highly skilled, and outperformed similar-aged wolf puppies who had higher levels of human interaction. Second, we address the claim that willingness to approach a stranger can explain the difference between dog and wolf pups' ability to succeed in gesture comprehension tasks. We explain the various controls in the original study that render this explanation insufficient, and demonstrate via model comparison that the covariance of species and temperament also make this parsing impossible. Overall, our additional analyses and considerations support the domestication hypothesis as laid out by Salomons et al. Current Biology, 31(14), 3137-3144.E11, (2021).


Assuntos
Lobos , Cães , Animais , Humanos , Lobos/fisiologia , Triticum , Domesticação , Gestos
8.
Mol Biol Evol ; 38(12): 5588-5609, 2021 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-34519828

RESUMO

The sterility or inviability of hybrid offspring produced from an interspecific mating result from incompatibilities between parental genotypes that are thought to result from divergence of loci involved in epistatic interactions. However, attributes contributing to the rapid evolution of these regions also complicates their assembly, thus discovery of candidate hybrid sterility loci is difficult and has been restricted to a small number of model systems. Here we reported rapid interspecific divergence at the DXZ4 macrosatellite locus in an interspecific cross between two closely related mammalian species: the domestic cat (Felis silvestris catus) and the Jungle cat (Felis chaus). DXZ4 is an interesting candidate due to its structural complexity, copy number variability, and described role in the critical yet complex biological process of X-chromosome inactivation. However, the full structure of DXZ4 was absent or incomplete in nearly every available mammalian genome assembly given its repetitive complexity. We compared highly continuous genomes for three cat species, each containing a complete DXZ4 locus, and discovered that the felid DXZ4 locus differs substantially from the human ortholog, and that it varies in copy number between cat species. Additionally, we reported expression, methylation, and structural conformation profiles of DXZ4 and the X chromosome during stages of spermatogenesis that have been previously associated with hybrid male sterility. Collectively, these findings suggest a new role for DXZ4 in male meiosis and a mechanism for feline interspecific incompatibility through rapid satellite divergence.


Assuntos
Felidae , Infertilidade Masculina , Animais , Gatos/genética , Felidae/genética , Genoma , Infertilidade Masculina/genética , Masculino , Cromossomo X/genética , Inativação do Cromossomo X
9.
Mol Ecol ; 31(21): 5440-5454, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-34585803

RESUMO

Admixture and introgression play a critical role in adaptation and genetic rescue that has only recently gained a deeper appreciation. Here, we explored the geographical and genomic landscape of cryptic ancestry of the endangered red wolf that persists within the genome of a ubiquitous sister taxon, the coyote, all while the red wolf has been extinct in the wild since the early 1980s. We assessed admixture across 120,621 single nucleotiode polymorphism (SNP) loci genotyped in 293 canid genomes. We found support for increased red wolf ancestry along a west-to-east gradient across the southern United States associated with historical admixture in the past 100 years. Southwestern Louisiana and southeastern Texas, the geographical zone where the last red wolves were known prior to extinction in the wild, contained the highest and oldest levels of red wolf ancestry. Further, given the paucity of inferences based on chromosome types, we compared patterns of ancestry on the X chromosome and autosomes. We additionally aimed to explore the relationship between admixture timing and recombination rate variation to investigate gene flow events. We found that X-linked regions of low recombination rates were depleted of introgression, relative to the autosomes, consistent with the large X effect and enrichment with loci involved in maintaining reproductive isolation. Recombination rate was positively correlated with red wolf ancestry across coyote genomes, consistent with theoretical predictions. The geographical and genomic extent of cryptic red wolf ancestry can provide novel genomic resources for recovery plans targeting the conservation of the endangered red wolf.


Assuntos
Canidae , Coiotes , Lobos , Animais , Estados Unidos , Lobos/genética , Coiotes/genética , Hibridização Genética , Genoma/genética , Genômica
10.
Mol Ecol ; 30(23): 6340-6354, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34161633

RESUMO

The endangered Mexican wolf (Canis lupus baileyi) is known to carry exceedingly low levels of genetic diversity. This could be (i) the result of long-term evolutionary patterns as they exist at the southernmost limit of the species distribution at a relatively reduced effective size, or (ii) due to rapid population decline caused by human persecution over the last century. If the former, purifying selection is expected to have minimized the impact of inbreeding. If the latter, rapid and recent declines in genetic diversity may have resulted in severe fitness consequences. To differentiate these hypotheses, we conducted comparative whole-genome analyses of five historical Mexican wolves (1907-1917) and 18 contemporary Mexican and grey wolves from North America and Eurasia. Based on whole-genome data, historical and modern Mexican wolves together form a discrete unit. Moreover, we found that modern Mexican wolves have reduced genetic diversity and increased inbreeding relative to the historical population, which was widespread across the southwestern United States and not restricted to Mexico as previously assumed. Finally, although Mexican wolves have evolved in sympatry with coyotes (C. latrans), we observed lower introgression between historical Mexican wolves and coyotes than with modern Mexican wolves, despite similarities in body size. Taken together, our data show that recent population declines probably caused the reduced level of genetic diversity, but not the observed differentiation of the Mexican wolves from other North American wolves.


Assuntos
Coiotes , Lobos , Animais , Coiotes/genética , Variação Genética , Genoma , México , Lobos/genética
11.
Bioscience ; 71(1): 73-84, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33442329

RESUMO

Recent advances in genomics have increased our understanding of geographic patterns of intraspecific variation and the importance of this variation in enhancing species' potential to adapt to novel threats. However, as part of an effort to limit the scope of the Endangered Species Act (ESA), the US government has proposed the removal of the gray wolf from the list of protected species on the basis of a claim that the statute permits a species to be declared recovered given the existence of a single presently secure population. We rebut this interpretation and propose a framework for the conservation of adaptive potential that builds on current agency practice in delineating subspecific recovery units and reconciles the definition of significance in the statute's "distinct population segment" and "significant portion of range" clauses. Such a coordinated policy would enhance the ESA's effectiveness in stemming loss of biodiversity in the face of climate change and other factors altering Earth's ecosystems.

12.
J Hered ; 112(5): 458-468, 2021 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-34132805

RESUMO

In North American gray wolves, black coat color is dominantly inherited via a 3 base pair coding deletion in the canine beta defensin 3 (CBD103) gene. This 3 base pair deletion, called the KB allele, was introduced through hybridization with dogs and subsequently underwent a selective sweep that increased its frequency in wild wolves. Despite apparent positive selection, KBB wolves have lower fitness than wolves with the KyB genotype, even though the 2 genotypes show no observable differences in black coat color. Thus, the KB allele is thought to have pleiotropic effects on as-yet unknown phenotypes. Given the role of skin-expressed CBD103 in innate immunity, we hypothesized that the KB allele influences the keratinocyte gene expression response to TLR3 pathway stimulation and/or infection by canine distemper virus (CDV). To test this hypothesis, we developed a panel of primary epidermal keratinocyte cell cultures from 24 wild North American gray wolves of both Kyy and KyB genotypes. In addition, we generated an immortalized Kyy line and used CRISPR/Cas9 editing to produce a KyB line on the same genetic background. We assessed the transcriptome-wide responses of wolf keratinocytes to the TLR3 agonist polyinosinic:polycytidylic acid (polyI:C), and to live CDV. K locus genotype did not predict the transcriptional response to either challenge, suggesting that variation in the gene expression response does not explain pleiotropic effects of the KB allele on fitness. This study supports the feasibility of using cell culture methods to investigate the phenotypic effects of naturally occurring genetic variation in wild mammals.


Assuntos
Vírus da Cinomose Canina , Lobos , Alelos , Animais , Vírus da Cinomose Canina/genética , Cães , Expressão Gênica , Receptor 3 Toll-Like/genética , Lobos/genética
13.
Mol Ecol ; 29(8): 1463-1475, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31821650

RESUMO

The host-associated microbiome is increasingly recognized as a critical player in health and immunity. Recent studies have shown that disruption of commensal microbial communities can contribute to disease pathogenesis and severity. Santa Catalina Island foxes (Urocyon littoralis catalinae) present a compelling system in which to examine microbial dynamics in wildlife due to their depauperate genomic structure and extremely high prevalence of ceruminous gland tumors. Although the precise cause is yet unknown, infection with ear mites (Otodectes cynotis) has been linked to chronic inflammation, which is associated with abnormal cell growth and tumor development. Given the paucity of genomic variation in these foxes, other dimensions of molecular diversity, such as commensal microbes, may be critical to host response and disease pathology. We characterized the host-associated microbiome across six body sites of Santa Catalina Island foxes, and performed differential abundance testing between healthy and mite-infected ear canals. We found that mite infection was significantly associated with reduced microbial diversity and evenness, with the opportunistic pathogen Staphylococcus pseudintermedius dominating the ear canal community. These results suggest that secondary bacterial infection may contribute to the sustained inflammation associated with tumor development. As the emergence of antibiotic resistant strains remains a concern of the medical, veterinary, and conservation communities, uncovering high relative abundance of S. pseudintermedius provides critical insight into the pathogenesis of this complex system. Through use of culture-independent sequencing techniques, this study contributes to the broader effort of applying a more inclusive understanding of molecular diversity to questions within wildlife disease ecology.


Assuntos
Microbiota , Ácaros , Animais , Raposas , Microbiota/genética , Staphylococcus
14.
Mol Ecol ; 29(10): 1764-1775, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31905256

RESUMO

Aggression is a quantitative trait deeply entwined with individual fitness. Mapping the genomic architecture underlying such traits is complicated by complex inheritance patterns, social structure, pedigree information and gene pleiotropy. Here, we leveraged the pedigree of a reintroduced population of grey wolves (Canis lupus) in Yellowstone National Park, Wyoming, USA, to examine the heritability of and the genetic variation associated with aggression. Since their reintroduction, many ecological and behavioural aspects have been documented, providing unmatched records of aggressive behaviour across multiple generations of a wild population of wolves. Using a linear mixed model, a robust genetic relationship matrix, 12,288 single nucleotide polymorphisms (SNPs) and 111 wolves, we estimated the SNP-based heritability of aggression to be 37% and an additional 14% of the phenotypic variation explained by shared environmental exposures. We identified 598 SNP genotypes from 425 grey wolves to resolve a consensus pedigree that was included in a heritability analysis of 141 individuals with SNP genotype, metadata and aggression data. The pedigree-based heritability estimate for aggression is 14%, and an additional 16% of the phenotypic variation was explained by shared environmental exposures. We find strong effects of breeding status and relative pack size on aggression. Through an integrative approach, these results provide a framework for understanding the genetic architecture of a complex trait that influences individual fitness, with linkages to reproduction, in a social carnivore. Along with a few other studies, we show here the incredible utility of a pedigreed natural population for dissecting a complex, fitness-related behavioural trait.


Assuntos
Agressão , Lobos , Animais , Comportamento Animal , Linhagem , Polimorfismo de Nucleotídeo Único , Reprodução , Estados Unidos , Lobos/genética , Wyoming
15.
J Hered ; 111(3): 249-262, 2020 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-32034410

RESUMO

This bibliography provides a collection of references that documents the evolution of studies evidencing interbreeding among Canis species in North America. Over the past several decades, advances in biology and genomic technology greatly improved our ability to detect and characterize species interbreeding, which has significance for understanding species in a changing landscape as well as for endangered species management. This bibliography includes a discussion within each category of interbreeding, the timeline of developing evidence, and includes a review of past research conducted on experimental crosses. Research conducted in the early 20th century is rich with detailed records and photographs of hybrid offspring development and behavior. With the progression of molecular methods, studies can estimate historical demographic parameters and detect chromosomal patterns of ancestry. As these methods continue to increase in accessibility, the field will gain a deeper and richer understanding of the evolutionary history of North American Canis.


Assuntos
Cruzamento , Canidae , Animais , Evolução Biológica , Coiotes , Cães , Hibridização Genética , América do Norte , Lobos
16.
J Hered ; 111(3): 277-286, 2020 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-32090268

RESUMO

The red wolf (Canis rufus), a legally recognized and critically endangered wolf, is known to interbreed with coyotes (Canis latrans). Declared extirpated in the wild in 1980, red wolves were reintroduced to northeastern North Carolina nearly a decade later. Interbreeding with coyotes was thought to be restricted to a narrow geographic region adjacent to the reintroduced population and largely believed to threaten red wolf recovery. However, red wolf ancestry was recently discovered in canids along the American Gulf Coast, igniting a broader survey of ancestry in southeastern canid populations. Here, we examine geographic and temporal patterns of genome-wide red wolf ancestry in 260 canids across the southeastern United States at over 164 000 SNP loci. We found that red wolf ancestry was most prevalent in canids sampled from Texas in the mid-1970s, although non-trivial amounts of red wolf ancestry persist in this region today. Further, red wolf ancestry was also observed in a subset of coyotes inhabiting North Carolina, despite management efforts to limit the occurrence of hybridization events. Lastly, we found no evidence of substantial red wolf ancestry in southeastern canids outside of these 2 admixture zones. Overall, this study provides a genome-wide survey of red wolf ancestry in canids across the southeastern United States, which may ultimately inform future red wolf restoration efforts.


Assuntos
Canidae/genética , Coiotes/genética , Introgressão Genética , Lobos/genética , Animais , Raposas/genética , Genética Populacional , Filogeografia , Sudeste dos Estados Unidos , Análise Espaço-Temporal
17.
Proc Biol Sci ; 286(1912): 20190716, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31575369

RESUMO

Variation across dog breeds presents a unique opportunity to investigate the evolution and biological basis of complex behavioural traits. We integrated behavioural data from more than 14 000 dogs from 101 breeds with breed-averaged genotypic data (n = 5697 dogs) from over 100 000 loci in the dog genome. We found high levels of among-breed heritability for 14 behavioural traits (the proportion of trait variance attributable to genetic similarity among breeds). We next identified 131 single nucleotide polymorphisms associated with breed differences in behaviour, which were found in genes that are highly expressed in the brain and enriched for neurobiological functions and developmental processes, suggesting that they may be functionally associated with behavioural differences. Our results shed light on the heritability and genetic architecture of complex behavioural traits and identify dogs as a powerful model in which to address these questions.


Assuntos
Comportamento Animal , Cães/fisiologia , Genótipo , Hereditariedade , Polimorfismo de Nucleotídeo Único , Animais , Cruzamento , Cães/genética , Genoma , Especificidade da Espécie
18.
Heredity (Edinb) ; 122(2): 133-149, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29880893

RESUMO

Admixture resulting from natural dispersal processes can potentially generate novel phenotypic variation that may facilitate persistence in changing environments or result in the loss of population-specific adaptations. Yet, under the US Endangered Species Act, policy is limited for management of individuals whose ancestry includes a protected taxon; therefore, they are generally not protected under the Act. This issue is exemplified by the recently re-established grey wolves of the Pacific Northwest states of Washington and Oregon, USA. This population was likely founded by two phenotypically and genetically distinct wolf ecotypes: Northern Rocky Mountain (NRM) forest and coastal rainforest. The latter is considered potentially threatened in southeast Alaska and thus the source of migrants may affect plans for their protection. To assess the genetic source of the re-established population, we sequenced a ~ 300 bp portion of the mitochondrial control region and ~ 5 Mbp of the nuclear genome. Genetic analysis revealed that the Washington wolves share ancestry with both wolf ecotypes, whereas the Oregon population shares ancestry with NRM forest wolves only. Using ecological niche modelling, we found that the Pacific Northwest states contain environments suitable for each ecotype, with wolf packs established in both environmental types. Continued migration from coastal rainforest and NRM forest source populations may increase the genetic diversity of the Pacific Northwest population. However, this admixed population challenges traditional management regimes given that admixture occurs between an adaptively distinct ecotype and a more abundant reintroduced interior form. Our results emphasize the need for a more precise US policy to address the general problem of admixture in the management of endangered species, subspecies, and distinct population segments.


Assuntos
Espécies em Perigo de Extinção , Lobos/crescimento & desenvolvimento , Distribuição Animal , Animais , Cruzamento , Conservação dos Recursos Naturais , Ecossistema , Espécies em Perigo de Extinção/estatística & dados numéricos , Feminino , Genótipo , Masculino , Noroeste dos Estados Unidos , Dinâmica Populacional , Lobos/classificação , Lobos/genética , Lobos/fisiologia
19.
Conserv Biol ; 32(4): 798-807, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29380417

RESUMO

Pathogens pose serious threats to human health, agricultural investment, and biodiversity conservation through the emergence of zoonoses, spillover to domestic livestock, and epizootic outbreaks. As such, wildlife managers are often tasked with mitigating the negative effects of disease. Yet, parasites form a major component of biodiversity that often persist. This is due to logistical challenges of implementing management strategies and to insufficient understanding of host-parasite dynamics. We advocate for an inclusive understanding of molecular diversity in driving parasite infection and variable host disease states in wildlife systems. More specifically, we examine the roles of genetic, epigenetic, and commensal microbial variation in disease pathogenesis. These include mechanisms underlying parasite virulence and host resistance and tolerance, and the development, regulation, and parasite subversion of immune pathways, among other processes. Case studies of devil facial tumor disease in Tasmanian devils (Sarcophilus harrisii) and chytridiomycosis in globally distributed amphibians exemplify the broad range of questions that can be addressed by examining different facets of molecular diversity. For particularly complex systems, integrative molecular analyses present a promising frontier that can provide critical insights necessary to elucidate disease dynamics operating across scales. These insights enable more accurate risk assessment, reconstruction of transmission pathways, discernment of optimal intervention strategies, and development of more effective and ecologically sound treatments that minimize damage to the host population and environment. Such measures are crucial when mitigating threats posed by wildlife disease to humans, domestic animals, and species of conservation concern.


Assuntos
Conservação dos Recursos Naturais , Marsupiais , Anfíbios , Animais , Animais Selvagens , Biodiversidade , Humanos
20.
Mol Biol Evol ; 33(8): 1967-78, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27189566

RESUMO

Gene expression levels change as an individual ages and responds to environmental conditions. With the exception of humans, such patterns have principally been studied under controlled conditions, overlooking the array of developmental and environmental influences that organisms encounter under conditions in which natural selection operates. We used high-throughput RNA sequencing (RNA-Seq) of whole blood to assess the relative impacts of social status, age, disease, and sex on gene expression levels in a natural population of gray wolves (Canis lupus). Our findings suggest that age is broadly associated with gene expression levels, whereas other examined factors have minimal effects on gene expression patterns. Further, our results reveal evolutionarily conserved signatures of senescence, such as immunosenescence and metabolic aging, between wolves and humans despite major differences in life history and environment. The effects of aging on gene expression levels in wolves exhibit conservation with humans, but the more rapid expression differences observed in aging wolves is evolutionarily appropriate given the species' high level of extrinsic mortality due to intraspecific aggression. Some expression changes that occur with age can facilitate physical age-related changes that may enhance fitness in older wolves. However, the expression of these ancestral patterns of aging in descendant modern dogs living in highly modified domestic environments may be maladaptive and cause disease. This work provides evolutionary insight into aging patterns observed in domestic dogs and demonstrates the applicability of studying natural populations to investigate the mechanisms of aging.


Assuntos
Envelhecimento/genética , Regulação da Expressão Gênica , Lobos/genética , Fatores Etários , Animais , Animais Selvagens , Evolução Biológica , Cães , Meio Ambiente , Feminino , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Masculino , Filogenia , Seleção Genética , Análise de Sequência de RNA/métodos , Fatores Sexuais
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