Project description:Through thousands of years of breeding and strong human selection, the dog (Canis lupus familiaris) exists today within hundreds of closed populations throughout the world, each with defined phenotypes. A singular geographic region with broad diversity in dog breeds presents an interesting opportunity to observe potential mechanisms of breed formation. Italy claims 14 internationally recognized dog breeds, with numerous additional local varieties. To determine the relationship among Italian dog populations, we integrated genetic data from 263 dogs representing 23 closed dog populations from Italy, seven Apennine gray wolves. Using 142,840 genome-wide SNPs, this dataset was used in the identification of breed development routes for the Italian breeds that included divergence from common populations for a specific purpose, admixture of regional stock with that from other regions, and isolated selection of local stock with specific attributes.
Project description:DNA structural variation (SV) comprises a major portion of genetic diversity, but its biological impact is unclear. We propose that the genetic history and extraordinary phenotypic variation of dogs make them an ideal mammal in which to study the effects of SV on biology and disease. The hundreds of existing dog breeds were created by selection of extreme morphological and behavioral traits. And along with those traits, each breed carries increased risk for different diseases. We used array CGH to create the first map of DNA copy number variation (CNV) or SV in dogs. The extent of this variation, and some of the gene classes affected, are similar to those of mice and humans. Most canine CNVs affect genes, including disease and candidate disease genes, and are thus likely to be functional. We identified many CNVs that may be breed or breed class specific. Cluster analysis of CNV regions showed that dog breeds tend to group according to breed classes. Our combined findings suggest many CNVs are (1) in linkage disequilibrium with flanking sequence, and (2) associated with breed specific traits. We discuss how a catalog of structural variation in dogs will accelerate the identification of the genetic basis of canine traits and diseases, beginning with the use of whole genome association and candidate CNV/gene approaches. Chen WK, Swartz JD, Rush LJ, Alvarez, CE. Mapping DNA structural variation in dogs. Genome Res. 2009. 19: 500 509 PMID: 19015322
Project description:The Italian island of Sardinia is well known in studies of human population isolates. It is also home to the Fonni's Dog, a breed of canine whose development was reliant on the functionality of the dog. Using genome-wide variant and sequence analyses, we have characterized the Fonni's Dog relative to 27 other dog breeds from the Mediterranean region. We determine introgression events relevant to Mediterranean breed development and describe how the Fonni's dog presents an intriguing model demonstrating the characteristics of traditional human population isolates and, in particular, exhibiting the unique demographic composition of the people of Sardinia.
Project description:The Italian island of Sardinia is well known in studies of human population isolates. It is also home to the Fonni's Dog, a breed of canine whose development was reliant on the functionality of the dog. Using genome-wide variant and sequence analyses, we have characterized the Fonni's Dog relative to 27 other dog breeds from the Mediterranean region. We determine introgression events relevant to Mediterranean breed development and describe how the Fonni's dog presents an intriguing model demonstrating the characteristics of traditional human population isolates and, in particular, exhibiting the unique demographic composition of the people of Sardinia.
Project description:The Italian island of Sardinia is well known in studies of human population isolates. It is also home to the Fonni's Dog, a breed of canine whose development was reliant on the functionality of the dog. Using genome-wide variant and sequence analyses, we have characterized the Fonni's Dog relative to 27 other dog breeds from the Mediterranean region. We determine introgression events relevant to Mediterranean breed development and describe how the Fonni's dog presents an intriguing model demonstrating the characteristics of traditional human population isolates and, in particular, exhibiting the unique demographic composition of the people of Sardinia.
Project description:DNA structural variation (SV) comprises a major portion of genetic diversity, but its biological impact is unclear. We propose that the genetic history and extraordinary phenotypic variation of dogs make them an ideal mammal in which to study the effects of SV on biology and disease. The hundreds of existing dog breeds were created by selection of extreme morphological and behavioral traits. And along with those traits, each breed carries increased risk for different diseases. We used array CGH to create the first map of DNA copy number variation (CNV) or SV in dogs. The extent of this variation, and some of the gene classes affected, are similar to those of mice and humans. Most canine CNVs affect genes, including disease and candidate disease genes, and are thus likely to be functional. We identified many CNVs that may be breed or breed class specific. Cluster analysis of CNV regions showed that dog breeds tend to group according to breed classes. Our combined findings suggest many CNVs are (1) in linkage disequilibrium with flanking sequence, and (2) associated with breed specific traits. We discuss how a catalog of structural variation in dogs will accelerate the identification of the genetic basis of canine traits and diseases, beginning with the use of whole genome association and candidate CNV/gene approaches. Chen WK, Swartz JD, Rush LJ, Alvarez, CE. Mapping DNA structural variation in dogs. Genome Res. 2009. 19: 500 509 PMID: 19015322 Array comparitive genomic hybridization analysis of structural variation in 9 dogs, and 1 lymphoma cell line.
Project description:Selective breeding of domestic dogs has generated diverse breeds often optimized for performing specialized tasks. Despite the heritability of breed-typical behavioral traits, identification of causal loci has proven challenging due to the complexity of canine population structure. We overcome longstanding difficulties in identifying genetic drivers of canine behavior by developing an innovative framework for understanding relationships between breeds and the behaviors that define them utilizing genetic data for over 4,000 domestic, semi-feral and wild canids and behavioral survey data for over 46,000 dogs. We identify ten major canine genetic lineages and their behavioral correlates and show that breed diversification is predominantly driven by non-coding regulatory variation. We determine that lineage-associated genes converge in neurodevelopmental co-expression networks, identifying a sheepdog-associated enrichment for interrelated axon guidance functions. This work presents a scaffold for canine diversification that positions the domestic dog as an unparalleled system for revealing the genetic origins of behavioral diversity.
Project description:The Italian island of Sardinia is well known in studies of human population isolates. It is also home to the Fonni's Dog, a breed of canine whose development was reliant on the functionality of the dog. Using genome-wide variant and sequence analyses, we have characterized the Fonni's Dog relative to 27 other dog breeds from the Mediterranean region. We determine introgression events relevant to Mediterranean breed development and describe how the Fonni's dog presents an intriguing model demonstrating the characteristics of traditional human population isolates and, in particular, exhibiting the unique demographic composition of the people of Sardinia. 4 canine samples representing 1 dog breed
Project description:Progressive retinal atrophy (PRA) is a common cause of blindness in many pure and mixed breed dogs (Canis lupus familiaris). The typical onset of PRA begins with gradual night vision loss followed by day vision loss due to the death of rod and cone receptors, respectively. There are currently no mutations or genes reported to be causative or associated with PRA in the Hungarian Puli. In this study, we use an extensive list of 53 known PRA genes to screen for putative causal variants in this breed of dog.