Logo: to the web site of Uppsala University

uu.sePublications from Uppsala University
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Whole-genome analyses provide no evidence for dog introgression in Fennoscandian wolf populations
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.ORCID iD: 0000-0002-8415-9259
Univ Oulu, Dept Ecol & Genet, Oulu, Finland..
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
Nat Resources Inst Finland Luke, Rovaniemi, Finland..
Show others and affiliations
2021 (English)In: Evolutionary Applications, E-ISSN 1752-4571, Vol. 14, no 3, p. 721-734Article in journal (Refereed) Published
Abstract [en]

Hybridization and admixture can threaten the genetic integrity of populations and be of particular concern to endangered species. Hybridization between grey wolves and dogs has been documented in many wolf populations worldwide and is a prominent example of human-mediated hybridization between a domesticated species and its wild relative. We analysed whole-genome sequences from >200 wolves and >100 dogs to study admixture in Fennoscandian wolf populations. A principal component analysis of genetic variation and Admixture showed that wolves and dogs were well-separated, without evidence for introgression. Analyses of local ancestry revealed that wolves had <1% mixed ancestry, levels comparable to the degree of mixed ancestry in many dogs, and likely not resulting from recent wolf-dog hybridization. We also show that the founders of the Scandinavian wolf population were genetically inseparable from Finnish and Russian Karelian wolves, pointing at the geographical origin of contemporary Scandinavian wolves. Moreover, we found Scandinavian-born animals among wolves sampled in Finland, demonstrating bidirectional gene flow between the Scandinavian Peninsula and eastern countries. The low incidence of admixture between wolves and dogs in Fennoscandia may be explained by the fact that feral dogs are rare in this part of Europe and that careful monitoring and management act to remove hybrids before they backcross into wolf populations.

Place, publisher, year, edition, pages
WILEY John Wiley & Sons, 2021. Vol. 14, no 3, p. 721-734
Keywords [en]
admixture, conservation genomics, grey wolf, hybridization, introgression
National Category
Evolutionary Biology
Identifiers
URN: urn:nbn:se:uu:diva-450533DOI: 10.1111/eva.13151ISI: 000587448300001PubMedID: 33767747OAI: oai:DiVA.org:uu-450533DiVA, id: diva2:1585284
Funder
Knut and Alice Wallenberg FoundationSwedish Research CouncilAvailable from: 2021-08-16 Created: 2021-08-16 Last updated: 2024-01-15Bibliographically approved
In thesis
1. Conservation genomics in inbred Scandinavian wolves using bioinformatic methods
Open this publication in new window or tab >>Conservation genomics in inbred Scandinavian wolves using bioinformatic methods
2024 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

With the recent and unprecedented progress in retrieving DNA sequence information from a large number of individuals of any species, conservation genetic research has entered a new phase. Specifically, it has become possible to study how genomes of endangered species respond to reductions in population size. Using genomic and bioinformatic approaches, in this thesis I investigate the contemporary Scandinavian wolf population founded 40 years ago by only three individuals, after the original population had been extirpated some decades earlier. The origin of the founders has been the subject of controversy, so I aimed to trace their origin using first male-specific Y chromosome sequences, and then whole-genome sequence data. I compared Scandinavian wolves to wolves from the nearby Finnish-Russian population as well as to publicly available wolf and dog samples from around the northern hemisphere, and found that the Scandinavian founders shared Y-haplotypes only with Finnish wolves. Consistent with this observation, when assessing population structure on the genomic scale, founders clustered with Finnish and Russian wolves, and an admixture analysis showed no other ancestries, nor traces of introgression from dogs. 

Small populations tend to have less genetic variation than larger populations, which might reduce their adaptive potential and increase the risk for extinction. A common measure used to investigate the genetic health of small populations is the genetic load, which is the fitness reduction of individuals due to accumulation of deleterious variants. I assessed the genetic load in Scandinavian wolves, divided into the components masked load (comprised of deleterious mutations in heterozygous state) and realized load (comprised of deleterious mutations in homozygous state), using both putatively deleterious single nucleotides and structural variants. I found that the realized load increased with every generation of inbreeding but was alleviated after genetic rescue events when new immigrants entered the population. Finally, I searched for the genetic basis of cryptorchidism, a testis condition that results in lowered fertility and is thought to be related to inbreeding depression. The trait is likely highly polygenic and the fact that only one significant association (to a region on the X chromosome) was found can be explained by that the number of available samples was very low, as is inevitable for small populations. 

In conclusion, this thesis explores the origin and the genetic health status of a small and recently founded natural population, and gives insights into how patterns of genetic load are affected by inbreeding and genetic rescue.  

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2024. p. 65
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 2351
Keywords
conservation genomics, Canis lupus, bioinformatics, Y chromosome, admixture, genetic load, structural variation, GWAS
National Category
Evolutionary Biology
Research subject
Biology with specialization in Evolutionary Genetics
Identifiers
urn:nbn:se:uu:diva-517653 (URN)978-91-513-1998-8 (ISBN)
Public defence
2024-02-16, Zootissalen, EBC, Villavägen 9, Uppsala, 10:00 (English)
Opponent
Supervisors
Available from: 2024-01-24 Created: 2023-12-15 Last updated: 2024-01-24

Open Access in DiVA

fulltext(623 kB)142 downloads
File information
File name FULLTEXT01.pdfFile size 623 kBChecksum SHA-512
75c66b45035fb92420283b164d133ae6b86fa13599d0b4e895d55b9c219301344a698eff883306d93968d4bbaefe8d4eec2a9cf779cec84781d68d73e8b1b15b
Type fulltextMimetype application/pdf

Other links

Publisher's full textPubMed

Authority records

Smeds, LinneaEllegren, Hans

Search in DiVA

By author/editor
Smeds, LinneaTirronen, KonstantinEllegren, Hans
By organisation
Evolutionary BiologyDepartment of Ecology and Genetics
In the same journal
Evolutionary Applications
Evolutionary Biology

Search outside of DiVA

GoogleGoogle Scholar
Total: 147 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 52 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf