Molecular Genetics of Sex Identification, Breed Ancestry and Polydactyly in the Norwegian Lundehund Breed

Abstract

The Norwegian Lundehund breed of dog has undergone a severe loss of genetic diversity as a result of inbreeding and epizootics of canine distemper. As a consequence, the breed is extremely homogeneous and accurate sex identification is not always possible by standard screening of X-chromosomal loci. To improve our genetic understanding of the breed we genotyped 17 individuals using a genome-wide array of 170 000 single nucleotide polymorphisms (SNPs). Standard analyses based on expected homozygosity of X-chromosomal loci failed in assigning individuals to the correct sex, as determined initially by physical examination and confirmed with the Y-chromosomal marker, amelogenin. This demonstrates that identification of sex using standard SNP assays can be erroneous in highly inbred individuals.

Cross-Breeding Is Inevitable to Conserve the Highly Inbred Population of Puffin Hunter: The Norwegian Lundehund

“…Based on the results of this study, together with previously published results on Lundehund genetic diversity [2,6,31], it is clear that immediate actions are needed to increase the genetic diversity in the current Lundehund population, and that the only option to secure the conservation of this rare breed is to introduce individuals from foreign breeds.…”

“…Molecular genetic studies have showed extremely low genetic diversity in the Lundehund [2,6,31] and close relatedness between individuals [6]. In a recent study (unpublished data, Stronen A) SNP genotypes were used to estimate heterozygosity in the Lundehund population.…”

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

“…The Lundehund population underwent at least two severe bottlenecks in the 1940s and 1960s where each event appears to have left only five inbred individuals [10–12]. The around 1500 dogs remaining at present appear to descend from only two individuals [13]. Accordingly, the Lundehund is now highly inbred [11–14]: for example [14] reported an inbreeding coefficient (F IS ) equal to 0.87 based on 26 microsatellite loci genotyped in 125 Lundehund individuals.…”

“…In an analysis of runs of homozygosity (ROH) in the Lundehund, [12] reported two genes, BMPR1B on chromosome 32 and PRRX2 on chromosome 9, previously reported as associated with polydactyly in mice. Furthermore, an intronic mutation in the preZRS of the LMBR1 gene on chromosome 16 has been implicated in polydactyly in several dog breeds including Lundehund [13, 18]. The Lundehund breed with low genetic variability may be a model population for the study of polydactyly [13], and further research could help illuminate the genetic basis for this feature.…”

“…Furthermore, an intronic mutation in the preZRS of the LMBR1 gene on chromosome 16 has been implicated in polydactyly in several dog breeds including Lundehund [13, 18]. The Lundehund breed with low genetic variability may be a model population for the study of polydactyly [13], and further research could help illuminate the genetic basis for this feature. Following outcrossing with other breeds, some offspring will likely not carry the trait.…”