The Institute of Canine Biology
  • HOME
  • Blog
  • Courses
    • COI BootCamp (FREE!)
    • Basic Population Genetics (FREE)
    • The Science of Canine Husbandry
    • Managing Genetics For the Future >
      • Syllabus - Managing Genetics for the Future
    • The Biology of Dogs (Open Reg )
    • DNA For Dog Breeders >
      • Syllabus - DNA for Dog Breeders
      • Open Reg - DNA For Dog Breeders
    • Understanding Hip & Elbow Dysplasia >
      • Open Reg - Understanding Hip & Elbow Dysplasia
    • Genetics of Behavior & Performance >
      • Syllabus - Genetics Behavior & Performance
      • Open Reg - Genetics of Behavior & Performance (Open Reg)
    • Strategies for Preservation Breeding >
      • Open Reg - Strategies for Preservation Breeding
    • Group Discounts
    • MORE FREE COURSES >
      • Quickie Genetics (Free!)
      • Heredity & Genetics (Free!)
      • Useful Genetics (Free!)
      • Basic Genetics Videos
  • Breed Preservation
    • Breed Status
    • Breeding for the future >
      • BFF Breed Groups
    • The "Elevator Pitch"
    • What's in the Gene Pool?
    • The Pox of Popular Sires
    • What population genetics can tell us about a breed
    • What population genetics can tell you...Tollers & Heelers
    • How to use kinship data
    • Using EBVs to breed better dogs >
      • How population size affects inbreeding
      • EBV Examples
    • How to read a dendrogram
    • Global Pedigree Project >
      • The Database
    • Finding the genes without DNA
    • How to read a heat map
  • Health Data
    • Bloat (Purdue Study)
    • Body Condition Score >
      • % Dysplastic vs BCS
    • Breed Comparions
    • Cancer
    • Cardiac
    • Cataracts
    • Caesareans
    • Deafness
    • Degenerative Myelopathy
    • Elbow Dysplasia
    • Epilepsy
    • Genetic Diversity
    • Genetic Diversity (MyDogDNA)
    • Hip Dysplasia >
      • Hip Dysplasia (Hou et al 2013)
    • Inbreeding Effects
    • Inbreeding (Gubbels)
    • Inbreeding (Dreger)
    • Lifespan
    • Litter size
    • Metabolic
    • mtDNA
    • Orthopedic
    • Mode of Inheritance
    • Patella Luxation
    • Thyroid
    • Portosystemic shunt
    • Purebred vs Mixed (UC Davis)
    • Purebred vs Mixed Breed (Bonnett)
    • Spay & Neuter Effects
    • Calboli et al 2008
    • Hodgman (1963)
    • Scott & Fuller (1965)
    • Stockard: Purebred crosses
    • Summers (2011)
  • Projects
    • How To Interpret Breed Analyses
    • Afghan Hound
    • More details about the Toller study
    • Belgian Tervuren >
      • Belgian Terv p2
      • Belgians- why population size matters
    • Bernese Mountain Dog
    • Boxer
    • Brussels Griffon
    • Bullmastiff
    • Canaan Dog >
      • Canaan analyses
    • Cesky Terrier >
      • Cesky genetic history
    • Chinook
    • Curly-coated Retriever
    • Doberman
    • Entelbucher Mountain Dog
    • Flatcoat Retriever
    • French Bulldog
    • German Shorthair
    • Golden Retriever >
      • Golden Retriever Pedigree Charts
    • Irish Water Spaniel >
      • IWS (6 Nov 17)
    • Labrador Retriever
    • Manchester Terrier
    • Mongolian Bankhar >
      • Research Updates
      • Bankhar 1
    • Norwegian Lundehund
    • Plummer Terrier
    • Otterhound
    • Portuguese Water Dog >
      • Portuguese Water Dog (pt 2)
    • Ridgeback
    • Schipperke
    • Standard Poodle >
      • The Problem With Poodles
      • 3poodle pedigree charts
      • 3Poodle Wycliff dogs
      • Poodle Genetics
    • Tibetan Spaniel
    • Tibetan Mastiff
    • West Highland White Terrier
    • Whippet
    • Wirehaired Pointing Griffons
    • UK KC Graphs >
      • UK KC Breed Status
      • UK Groups
      • KC Gundogs
      • KC Hounds
      • KC Terriers >
        • Terriers (select breeds)
      • KC Pastoral
      • KC Toys
      • KC Working
      • KC Utility
      • Australian KC
    • Breed outcrossing programs
  • Resources
    • Genetics Databases
    • Stud Books >
      • American Kennel Club stud books
      • Field Dog stud books
      • The Kennel Club (UK)
    • Learn
    • Videos about dog genetics
    • The Amazing Things Dogs Do! (videos) >
      • Livestock Management
      • Livestock guarding
      • Transportation, exploration, racing
      • Conservation & wildlife management
      • Detection Dogs
      • Medicine & Research
      • Entertainment
      • AKC/CHF Podcasts
    • Read & Watch
    • Bookshelf
  • Preventing Uterine Inertia

Finding genes without DNA

The information produced by population genetic analysis of a breed - in particular, a statistic called "kinship" - can be used to identify groupings of dogs that are more similar to each other genetically than they are to other groups.  This technique is called "cluster analysis" and was used in the study of Icelandic Sheepdogs by Oliehoek et al (2009) that we have discussed elsewhere.  

The same technique can be used to identify dogs likely to carry the genes for a particular trait (1).  A population of 252 Labrador Retrievers owned by the Royal Dutch Guide Dog for the Blind Association were screened for elbow dysplasia using clinical signs of fragmented coronoid process.  Seventeen percent of these dogs were found to be affected.  Population genetic analysis of the pedigrees of these dogs followed by cluster analysis allowed the researchers to isolate groups of dogs that were more closely related to each other (at least the 0.125 level of relatedness) than to dogs in other groups.  They then looked for patterns in the distribution of elbow dysplasia in these genetically distinct clusters.

Picture
Cluster analysis of Labrador Retrievers in this study. The dogs with affected elbows are indicated by shading.
They found 31 clusters of dogs that had a relatedness at least 0.125, and were genetically distinct from the other clusters.  From the dendrogram of the clusters (the funny tree-like graph), it was clear that the cases of elbow dysplasia were all found in five groups of dogs that were closely related to each other.  In these 5 clusters, the incidence was greater than 27%, while for all the others it was zero.

What this study shows so clearly is the enormous amount of information that can be leveraged from just pedigrees and some data on occurrence of a particular trait or disease.  They were able to accomplish this using relatively small subpopulations of the entire breed, but they note that the most accurate estimations of genetic similarity among individuals would be obtained using pedigrees that extend back to founders.



“A knowledge of the distribution of an inherited disease among clusters of related animals may help to provide the means to select against disease, while maintaining the heterogeneity of the population.  The clusters of dogs at risk may also provide a basis for the selection of animals for molecular genetic studies to search for markers of the genes underlying the disease.”


1)  Ubbink, GJ, HAW Hazewinkel, J Rothuizen, J van de Broek, & WTC Wolvekamp.  1998.  Cluster analysis of the genetic heterogeneity and disease distributions in purebred dog populations.  Veterinary Record 142: 209-213.

Blog

News


About Us

Contact Us








Copyright © 2012-2017 Institute of Canine Biology
Picture
Picture