Genome-wide association study for morphological and hunting-behavior traits in Braque Français Type Pyrénées dogs: A preliminary study.

High-throughput genotyping offers great potential to increase our understanding of the genomic basis of canid variation. Braque Français Type Pyrénées (BRA) are smart, agile, and friendly dogs originally developed for tracking, hunting, and retrieving feathered game. On a population of 44 unrelated BRA dogs, single nucleotide polymorphism (SNP) genotype data from the CanineHD Whole-Genome Genotyping BeadChip and evaluation scores for 12 traits related to morphology and hunting performance were available. After quality filtering, 95,859 SNPs on the 38 dog autosomes (CFA) were retained. Phenotypic scores were expressed on a scale from 1 (worst) to 6 (best) and were mostly poorly to moderately correlated except for some morphological traits (e.g. r = 0.81 between the conformation of the head and that of the eye). From GWAS, a total of 378 SNP-phenotype associations with posterior odds of association > 1 have been detected. The strongest associations were found for the eye conformation, for the skull/muzzle ratio, and for connection to the hunter. These included both new and previously identified markers and genes potentially involved with type and behavior traits in BRA. Six of the significant markers mapped within SETDB2, a gene known to be related to pointing behavior in dogs. These results advance our understanding of the genetic basis for morphology and hunting behavior in dogs and identify new variants which are potential targets for further research.

A Genome-Wide Detection of Copy Number Variations Using SNP Genotyping Arrays in Braque Français Type Pyrénées Dogs.

Copy number variants (CNVs) are an important source of genetic variation complementary to single nucleotide polymorphisms (SNPs). Only few studies have been conducted in dogs on CNVs derived from high-density SNP array data, and many canine breeds still remain uncharacterized, e.g., the Braque Français, type Pyrénées breed (BRA). Therefore, in an effort to more comprehensively investigate the canine genome for CNVs, we used a high-density SNP array (170 K) to discover CNVs in BRA. The CNV regions (CNVRs) were identified through the merging of two different CNVRs datasets, obtained separately from SNP data using the PennCNV and SVS software. A total of 45 stringent CNVRs, ranging from 3.5 kb to 458,716 kb in length were detected in 26 dog samples. Results overlapped moderately in comparison with previous studies on CNVs in dogs, leading to the identification of 16 novel CNVRs. A total of 159 genes were annotated in the CNVRs detected with stringent quality criteria in particular high classification stringency and false discovery rate correction. The gene ontology enrichment analysis provided information on biological processes and cellular components related to muscle structure development and muscle cell differentiation. Considering that BRA is a breed used for speed in hunting and retrieval, for the ability to find feathered game, and for pointing, we can hypothesize that selection for such hunting behavior could have driven, at least in part, the presence of these genes into the CNVRs.

Genomic characterization of the Braque Français type Pyrénées dog and relationship with other breeds.

The evaluation of genetic variability is a useful research tool for the correct management of selection and conservation strategies in dog breeds. In addition to pedigree genealogies, genomic data allow a deeper knowledge of the variability and genetic structure of populations. To date, many dog breeds, such as small regional breeds, still remain uncharacterized. Braque Français type Pyrénées (BRA) is a dog breed originating from a very old type of gun-dog used for pointing the location of game birds to hunters. Despite the ancient background, the knowledge about levels of genetic diversity, degree of inbreeding and population structure is scarce. This may raise concerns on the possibility that few inbred bloodlines may dominate the breed, and on its future health. The aim of this work was therefore to provide a high-resolution representation of the genome-wide diversity and population structure of BRA dogs, using the 170K genome-wide SNP array. Genome-wide polymorphisms in BRA were compared with those of other worldwide dog breeds. Between-dog relationships estimated from genomic data were very similar to pedigree relationships (Pearson correlation rg,a = 0.92). Results showed that BRA generally presents moderate levels of genetic diversity when compared with the major canine breeds. The estimated effective population size (recent Ne = 51) shows a similar declining pattern over generations as all other dog breeds, pointing at a common demographic history of modern canine breeds, clearly different from the demography of feral wolves. Multidimensional scaling (MDS), Bayesian clustering and Neighbor Joining tree were used to visualize and explore the genetic relationships among breeds, and revealed that BRA was highly differentiated and presented only low levels of admixture with other breeds. Brittany Spaniel, English Setter, Gordon Setter and Weimaraner dogs are the closest breeds to BRA. The exact reason for BRA being so divergent from other dog breeds, based on these results, is not yet clear. Further studies including additional ≪braccoid≫ breeds will be needed to refine the results presented here and to investigate the origin of the BRA breed. Nonetheless, the genome-wide characterization reported here provides a comprehensive insight into the genome diversity and population structure of the Braque Français, type Pyrénées breed.

Genome-wide diversity and runs of homozygosity in the "Braque Français, type Pyrénées" dog breed.

OBJECTIVE: Braque Français, type Pyrénées is a French hunting-dog breed whose origin is traced back to old pointing gun-dogs used to assist hunters in finding and retrieving game. This breed is popular in France, but seldom seen elsewhere. Despite the ancient background, the literature on its genetic characterization is surprisingly scarce. A recent study looked into the demography and inbreeding using pedigree records, but there is yet no report on the use of molecular markers in this breed. The aim of this work was to genotype a population of Braque Français, type Pyrénées dogs with the high-density SNP array to study the genomic diversity of the breed. RESULTS: The average observed ([Formula: see text]) and expected ([Formula: see text]) heterozygosity were 0.371 ([Formula: see text]) and 0.359 ([Formula: see text]). Effective population size ([Formula: see text]) was 27.5635 runs of homozygosity (ROH) were identified with average length of 2.16 MB. A ROH shared by [Formula: see text] of the dogs was detected at the beginning of chromosome 22. Inbreeding coefficients from marker genotypes were in the range [Formula: see text]. Inbreeding estimated from ROH ([Formula: see text]) had mean [Formula: see text]), with range [0.0526, 0.225]. These results show that the Braque Français, type Pyrénées breed is a relatively inbred population, but with still sufficient genetic variability for conservation and genetic improvement.