Hundi (Canis lupus) populatsioonid Eestis ja Euroopas: geneetiline mitmekesisus, populatsiooni struktuur ja -protsessid ning hübridiseerimine koertega

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Ajal, mil mitmete hundipopulatsioonide levila on Euroopas suurenemas, on teadmised hundi populatsioonigeneetikast vajalikud liigi jaoks oluliste kaitse- ja majandamisotsuste tegemiseks ja seda nii kohalike populatsioonide kui ka üleeuroopalisel tasandil. Käesoleva töö peamisteks eesmärkideks oli uurida Eesti ja Läti hundipopulatsioonide struktuuri ja –protsesse, hübridiseerumist koertega ning laiemalt kogu Euroopa huntide ruumilis-geneetilise mitmekesisuse mustreid ja trende. Kasutades nii emaliini, isaliini kui ka biparentaalseid geneetilisi markereid kombineerivat analüüsi, tuvastasime Eestis (esmakordselt) ja Lätis hundi ja koera hübriidid, sealjuures kaks hübriidi Lätist esindasid väga haruldast, Euroopas esmakordselt tuvastatud hübridiseerimisjuhtumit - emase koera ja isase hundi vahel. Eestit ja Lätit hõlmav hundipopulatsiooni geneetilisel analüüsil leiti neli geneetiliselt eristuvat rühma ning uudne DResD analüüs tuvastas populatsioonis migratsioonikoridori ning liikumisbarjääre ja kontakttsoone eri geneetiliste rühmade vahel. Suuremat osa Euroopa hundipopulatsioonidest hõlmav meta-analüüs tuvastas olulise ruumilise mitmekesisuse trendi – huntide madalaim geneetiline mitmekesisus esines Euroopa edelaosas ja kõrgeim kirdeosas. Tulemustes selgunud ruumilise autokorrelatsiooni vahemik 650-850 km näitab, et konkreetse hundipopulatsiooni geneetilist mitmekesisust võivad mõjutada hundipopulatsioonid, mis asuvad kuni 850 km kaugusel. Enamik Euroopa hundipopulatsioonidest on silmitsi sarnaste, inimese poolt otseselt või kaudselt seotud ohtudega: küttimine (sealhulgas salaküttimine), inimeste madal sallivus hundi suhtes, konfliktid kariloomade murdmise tõttu, elupaikade hävimine ning võimalik hübridiseerumine koertega. Selleks, et hunt säiliks Euroopas pikka aega ja soodsas seisundis, on vaja suurendada Euroopa hundipopulatsioonide üldist arvukust ja soodustada loomade levikut ja populatsioonide-siseseid ja -vahelisi seoseid. Hundi teaduspõhiseks kaitsmiseks ja majandamiseks nii piirkondlikel kui ka üleeuroopalisel skaalal, on hundipopulatsioone vaja hallata kui bioloogilisi üksusi, mis nõuab kõiki Euroopa hundipopulatsioone hõlmavaid täiendavaid geneetilisi analüüse, et teha kindlaks populatsioonide täpne arv, ruumiline jaotus, geenisiirde ulatused ning hübridiseerumise sageduse koertega.As many wolf populations in Europe are expanding their range, knowledge of population genetics are of great importance for effective conservation and management of the species at both local and over-European scales. The main goal of this thesis was to provide information on wolf population structure and processes in Europe with a particular emphasis on Estonia and Latvia, including the wolf-dog hybridization. Using a combined analysis of maternal, paternal and biparental genetic markers, hybridization between grey wolf and domestic dog was ascertained in Estonia (for the first time) and in Latvia. The two hybrids from Latvia represented a very rare case of hybridization – the first record from Europe – between a female dog and a male wolf. Population structure analysis demonstrated that wolf popu¬lation shared between Estonia and Latvia is represented by four genetic groups. The spatially explicit DResD analysis provided clear evidence of spatial variation of genetic divergence, revealing a migration corridor, barriers, and several contact zones between different genetic groups. In a meta-analysis covering most of the European wolf populations, significant spatial trend in heterozygosity across Europe from south-west (lowest genetic diversity) to north-east (highest) was found. The range of spatial autocorrelation of 650−850 km suggests, that the genetic diversity of a given wolf population can be influenced by populations up to 850 km away. Various human-related factors are undoubtedly the main source of threats to wolf populations in Europe: the majority of populations face similar common threats such as overharvesting (including poaching), low public acceptance, conflicts due to livestock depredation, habitat destruction, barriers to gene flow and interactions with dogs leading to possible hybridization. For the long-term survival and favourable conservation status of European wolves there is a need to increase the overall population size and favour wolf dispersal and connectivity among and within populations. For science-based wolf conservation and manage¬ment at regional and Europe-wide scales it was suggested to manage wolf populations according to biological units, which requires additional genetic analysis covering all wolf populations in Europe to define the exact number and spatial distribution of populations

First report of highly pathogenic Echinococcus granulosus genotype G1 in dogs in a European urban environment

BACKGROUND: Echinococcus granulosus and E. multilocularis are tapeworm parasites of major medical and veterinary importance, causing cystic and alveolar echinococcosis, respectively. Both diseases are listed among the most severe parasitic diseases in humans, representing 2 of the 17 neglected diseases prioritised by the World Health Organisation. However, little is known about the role of urban animals in transmission of both parasite species. FINDINGS: A sensitive non-invasive genetic method was used to monitor E. granulosus and E. multilocularis infection among dog faecal samples collected from an urban area in Estonia in 2012–13. Out of 181 dog faecal samples analysed, 2.2% tested positive for E. granulosus, determined by sequencing as genotype G1. None of the samples tested positive for E. multilocularis. CONCLUSIONS: We report contamination of an urban environment with highly pathogenic E. granulosus G1 disseminated by dogs, and a potential risk to human health

The extinct Sicilian wolf shows a complex history of isolation and admixture with ancient dogs

The Sicilian wolf remained isolated in Sicily from the end of the Pleistocene until its extermination in the 1930s–1960s. Given its long-term isolation on the island and distinctive morphology, the genetic origin of the Sicilian wolf remains debated. We sequenced four nuclear genomes and five mitogenomes from the seven existing museum specimens to investigate the Sicilian wolf ancestry, relationships with extant and extinct wolves and dogs, and diversity. Our results show that the Sicilian wolf is most closely related to the Italian wolf but carries ancestry from a lineage related to European Eneolithic and Bronze Age dogs. The average nucleotide diversity of the Sicilian wolf was half of the Italian wolf, with 37–50% of its genome contained in runs of homozygosity. Overall, we show that, by the time it went extinct, the Sicilian wolf had high inbreeding and low-genetic diversity, consistent with a population in an insular environmen

Article The extinct Sicilian wolf shows a complex history of isolation and admixture with ancient dogs

The Sicilian wolf remained isolated in Sicily from the end of the Pleistocene until its extermination in the 1930s-1960s. Given its long-term isolation on the island and distinctive morphology, the genetic origin of the Sicilian wolf remains debated. We sequenced four nuclear genomes and five mitogenomes from the seven existing museum specimens to investigate the Sicilian wolf ancestry, rela-tionships with extant and extinct wolves and dogs, and diversity. Our results show that the Sicilian wolf is most closely related to the Italian wolf but carries ancestry from a lineage related to European Eneolithic and Bronze Age dogs. The average nucleotide diversity of the Sicilian wolf was half of the Italian wolf, with 37-50% of its genome contained in runs of homozygosity. Overall, we show that, by the time it went extinct, the Sicilian wolf had high inbreeding and low-genetic diversity, consistent with a population in an insular environment

Unravelling the Scientific Debate on How to Address Wolf-Dog Hybridization in Europe

Anthropogenic hybridization is widely perceived as a threat to the conservation of biodiversity. Nevertheless, to date, relevant policy and management interventions are unresolved and highly convoluted. While this is due to the inherent complexity of the issue, we hereby hypothesize that a lack of agreement concerning management goals and approaches, within the scientific community, may explain the lack of social awareness on this phenomenon, and the absence of effective pressure on decision-makers. By focusing on wolf x dog hybridization in Europe, we hereby (a) assess the state of the art of issues on wolf x dog hybridization within the scientific community, (b) assess the conceptual bases for different viewpoints, and (c) provide a conceptual framework aiming at reducing the disagreements. We adopted the Delphi technique, involving a three-round iterative survey addressed to a selected sample of experts who published at Web of Science listed journals, in the last 10 years on wolf x dog hybridization and related topics. Consensus was reached that admixed individuals should always be defined according to their genetic profile, and that a reference threshold for admixture (i.e., q-value in assignment tests) should be formally adopted for their identification. To mitigate hybridization, experts agreed on adopting preventive, proactive and, when concerning small and recovering wolf populations, reactive interventions. Overall, experts' consensus waned as the issues addressed became increasingly practical, including the adoption of lethal removal. We suggest three non-mutually exclusive explanations for this trend: (i) value-laden viewpoints increasingly emerge when addressing practical issues, and are particularly diverging between experts with different disciplinary backgrounds (e.g., ecologists, geneticists); (ii) some experts prefer avoiding the risk of potentially giving carte blanche to wolf opponents to (illegally) remove wolves, based on the wolf x dog hybridization issue; (iii) room for subjective interpretation and opinions result from the paucity of data on the effectiveness of different management interventions. These results have management implications and reveal gaps in the knowledge on a wide spectrum of issues related not only to the management of anthropogenic hybridization, but also to the role of ethical values and real-world management concerns in the scientific debate

The European Reference Genome Atlas: piloting a decentralised approach to equitable biodiversity genomics.

ABSTRACT: A global genome database of all of Earth’s species diversity could be a treasure trove of scientific discoveries. However, regardless of the major advances in genome sequencing technologies, only a tiny fraction of species have genomic information available. To contribute to a more complete planetary genomic database, scientists and institutions across the world have united under the Earth BioGenome Project (EBP), which plans to sequence and assemble high-quality reference genomes for all ∼1.5 million recognized eukaryotic species through a stepwise phased approach. As the initiative transitions into Phase II, where 150,000 species are to be sequenced in just four years, worldwide participation in the project will be fundamental to success. As the European node of the EBP, the European Reference Genome Atlas (ERGA) seeks to implement a new decentralised, accessible, equitable and inclusive model for producing high-quality reference genomes, which will inform EBP as it scales. To embark on this mission, ERGA launched a Pilot Project to establish a network across Europe to develop and test the first infrastructure of its kind for the coordinated and distributed reference genome production on 98 European eukaryotic species from sample providers across 33 European countries. Here we outline the process and challenges faced during the development of a pilot infrastructure for the production of reference genome resources, and explore the effectiveness of this approach in terms of high-quality reference genome production, considering also equity and inclusion. The outcomes and lessons learned during this pilot provide a solid foundation for ERGA while offering key learnings to other transnational and national genomic resource projects.info:eu-repo/semantics/publishedVersio

The European Reference Genome Atlas: piloting a decentralised approach to equitable biodiversity genomics

A genomic database of all Earth’s eukaryotic species could contribute to many scientific discoveries; however, only a tiny fraction of species have genomic information available. In 2018, scientists across the world united under the Earth BioGenome Project (EBP), aiming to produce a database of high-quality reference genomes containing all ~1.5 million recognized eukaryotic species. As the European node of the EBP, the European Reference Genome Atlas (ERGA) sought to implement a new decentralised, equitable and inclusive model for producing reference genomes. For this, ERGA launched a Pilot Project establishing the first distributed reference genome production infrastructure and testing it on 98 eukaryotic species from 33 European countries. Here we outline the infrastructure and explore its effectiveness for scaling high-quality reference genome production, whilst considering equity and inclusion. The outcomes and lessons learned provide a solid foundation for ERGA while offering key learnings to other transnational, national genomic resource projects and the EBP.info:eu-repo/semantics/publishedVersio

Wolf population genetics in Europe: a systematic review, meta-analysis and suggestions for conservation and management

The grey wolf (Canis lupus) is an iconic large carnivore that has increasingly been recognized as an apex predator with intrinsic value and a keystone species. However, wolves have also long represented a primary source of human–carnivore conflict, which has led to long-term persecution of wolves, resulting in a significant decrease in their numbers, genetic diversity and gene flow between populations. For more effective protection and management of wolf populations in Europe, robust scientific evidence is crucial. This review serves as an analytical summary of the main findings from wolf population genetic studies in Europe, covering major studies from the ‘pre-genomic era’ and the first insights of the ‘genomics era’. We analyse, summarize and discuss findings derived from analyses of three compartments of the mammalian genome with different inheritance modes: maternal (mitochondrial DNA), paternal (Y chromosome) and biparental [autosomal microsatellites and single nucleotide polymorphisms (SNPs)]. To describe large-scale trends and patterns of genetic variation in European wolf populations, we conducted a meta-analysis based on the results of previous microsatellite studies and also included new data, covering all 19 European countries for which wolf genetic information is available: Norway, Sweden, Finland, Estonia, Latvia, Lithuania, Poland, Czech Republic, Slovakia, Germany, Belarus, Russia, Italy, Croatia, Bulgaria, Bosnia and Herzegovina, Greece, Spain and Portugal. We compared different indices of genetic diversity in wolf populations and found a significant spatial trend in heterozygosity across Europe from south-west (lowest genetic diversity) to north-east (highest). The range of spatial autocorrelation calculated on the basis of three characteristics of genetic diversity was 650−850 km, suggesting that the genetic diversity of a given wolf population can be influenced by populations up to 850 km away. As an important outcome of this synthesis, we discuss the most pressing issues threatening wolf populations in Europe, highlight important gaps in current knowledge, suggest solutions to overcome these limitations, and provide recommendations for science-based wolf conservation and management at regional and Europe-wide scales

Bucking the trend in wolf-dog hybridization: first evidence from europe of hybridization between female dogs and male wolves.

Studies on hybridization have proved critical for understanding key evolutionary processes such as speciation and adaptation. However, from the perspective of conservation, hybridization poses a concern, as it can threaten the integrity and fitness of many wild species, including canids. As a result of habitat fragmentation and extensive hunting pressure, gray wolf (Canis lupus) populations have declined dramatically in Europe and elsewhere during recent centuries. Small and fragmented populations have persisted, but often only in the presence of large numbers of dogs, which increase the potential for hybridization and introgression to deleteriously affect wolf populations. Here, we demonstrate hybridization between wolf and dog populations in Estonia and Latvia, and the role of both genders in the hybridization process, using combined analysis of maternal, paternal and biparental genetic markers. Eight animals exhibiting unusual external characteristics for wolves - six from Estonia and two from Latvia - proved to be wolf-dog hybrids. However, one of the hybridization events was extraordinary. Previous field observations and genetic studies have indicated that mating between wolves and dogs is sexually asymmetrical, occurring predominantly between female wolves and male dogs. While this was also the case among the Estonian hybrids, our data revealed the existence of dog mitochondrial genomes in the Latvian hybrids and, together with Y chromosome and autosomal microsatellite data, thus provided the first evidence from Europe of mating between male wolves and female dogs. We discuss patterns of sexual asymmetry in wolf-dog hybridization

Data from: Spatial genetic analyses reveal cryptic population structure and migration patterns in a continuously harvested grey wolf (Canis lupus) population in north-eastern Europe

Spatial genetics is a relatively new field in wildlife and conservation biology that is becoming an essential tool for unravelling the complexities of animal population processes, and for designing effective strategies for conservation and management. Conceptual and methodological developments in this field are therefore critical. Here we present two novel methodological approaches that further the analytical possibilities of STRUCTURE and DResD. Using these approaches we analyse structure and migrations in a grey wolf (Canis lupus) population in north-eastern Europe. We genotyped 16 microsatellite loci in 166 individuals sampled from the wolf population in Estonia and Latvia that has been under strong and continuous hunting pressure for decades. Our analysis demonstrated that this relatively small wolf population is represented by four genetic groups. We also used a novel methodological approach that uses linear interpolation to statistically test the spatial separation of genetic groups. The new method, which is capable of using program STRUCTURE output, can be applied widely in population genetics to reveal both core areas and areas of low significance for genetic groups. We also used a recently developed spatially explicit individual-based method DResD, and applied it for the first time to microsatellite data, revealing a migration corridor and barriers, and several contact zones