Genetic rescue of an endangered domestic animal through outcrossing with closely related breeds: A case study of the Norwegian Lundehund

Astrid V Stronen; Elina Salmela; Birna K Baldursdóttir; Peer Berg; Ingvild S Espelien; Kirsi Järvi; Henrik Jensen; Torsten N Kristensen; Claudia Melis; Tommaso Manenti; Hannes Lohi; Cino Pertoldi

doi:10.1371/journal.pone.0177429

Genetic rescue of an endangered domestic animal through outcrossing with closely related breeds: A case study of the Norwegian Lundehund

PLoS One. 2017 Jun 1;12(6):e0177429. doi: 10.1371/journal.pone.0177429. eCollection 2017.

Authors

Astrid V Stronen¹, Elina Salmela^{2

3}, Birna K Baldursdóttir⁴, Peer Berg⁵, Ingvild S Espelien⁶, Kirsi Järvi², Henrik Jensen⁷, Torsten N Kristensen^{1

8}, Claudia Melis^{7

9}, Tommaso Manenti⁸, Hannes Lohi², Cino Pertoldi^{1

10}

Affiliations

¹ Section of Biology and Environmental Science, Department of Chemistry and Bioscience, Aalborg University, Aalborg Øst, Denmark.
² Research Programs Unit, Molecular Neurology and Department of Veterinary Biosciences, University of Helsinki, and Folkhälsan Research Center, Helsinki, Finland.
³ Department of Biosciences, University of Helsinki, Helsinki, Finland.
⁴ Icelandic Genetic Resource Center, Hvanneyri, Borganes, Iceland.
⁵ Nordic Genetic Resource Center, Ås, Norway.
⁶ Norwegian Lundehund Club, Tangen, Trondheim, Norway.
⁷ Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.
⁸ Department of Biosciences, Section for Genetics, Ecology and Evolution, Aarhus University, Aarhus C, Denmark.
⁹ Queen Maud University College of Early Childhood Education, Trondheim, Norway.
¹⁰ Aalborg Zoo, Aalborg, Denmark.

Abstract

Genetic rescue, outcrossing with individuals from a related population, is used to augment genetic diversity in populations threatened by severe inbreeding and extinction. The endangered Norwegian Lundehund dog underwent at least two severe bottlenecks in the 1940s and 1960s that each left only five inbred dogs, and the approximately 1500 dogs remaining world-wide today appear to descend from only two individuals. The Lundehund has a high prevalence of a gastrointestinal disease, to which all remaining dogs may be predisposed. Outcrossing is currently performed with three Nordic Spitz breeds: Norwegian Buhund, Icelandic Sheepdog, and Norrbottenspets. Examination of single nucleotide polymorphism (SNP) genotypes based on 165K loci in 48 dogs from the four breeds revealed substantially lower genetic diversity for the Lundehund (HE 0.035) than for other breeds (HE 0.209-0.284). Analyses of genetic structure with > 15K linkage disequilibrium-pruned SNPs showed four distinct genetic clusters. Pairwise FST values between Lundehund and the candidate breeds were highest for Icelandic Sheepdog, followed by Buhund and Norrbottenspets. We assessed the presence of outlier loci among candidate breeds and examined flanking genome regions (1 megabase) for genes under possible selection to identify potential adaptive differences among breeds; outliers were observed in flanking regions of genes associated with key functions including the immune system, metabolism, cognition and physical development. We suggest crossbreeding with multiple breeds as the best strategy to increase genetic diversity for the Lundehund and to reduce the incidence of health problems. For this project, the three candidate breeds were first selected based on phenotypes and then subjected to genetic investigation. Because phenotypes are often paramount for domestic breed owners, such a strategy could provide a helpful approach for genetic rescue and restoration of other domestic populations at risk, by ensuring the involvement of owners, breeders and managers at the start of the project.

MeSH terms

Animals
Animals, Domestic / genetics*
Breeding*
Crosses, Genetic*
Dogs / genetics*
Endangered Species*

Grants and funding

AVS received funding from the Danish Natural Science Research Council (postdoctoral grant 1337-00007). The study was partly supported by the Danish Natural Science Research Council grant number: #21-01- 0526, #21-03-0125 and 95095995, and the Aalborg Zoo Conservation Foundation (AZCF) for CP, the Jane and Aatos Erkko Foundation (HL), the Jenny and Antti Wihuri Foundation (ES), the Academy of Finland (HL), and Biocentrum Helsinki (HL). HJ was supported by grant number 221956 from the Research Council of Norway. A portion of the SNP analyses was financed by the Norwegian Genetic Resource Center.