The Dog and Its Genome

Edited by:
  • Elaine A. Ostrander,
  • Urs Giger &
  • Kerstin Lindblad-Toh
Cold Spring Harbor Laboratory Press: 2005. 584 pp. $135, £80 0879697423 | ISBN: 0-879-69742-3
Boxer tricks: Tasha's genome will help researchers to understand human genetic diseases. Credit: NHGRI/MIT

Genome technology has found its way into the living room with the completion of the whole-genome sequence of the domestic dog Canis familiaris, from a female boxer called Tasha. Finished just a year after its initiation in 2003, the remarkably complete sequence (representing an estimated 99% of the dog's 2.4 billion base pairs) achieves 7.5-fold coverage of the genome and is a major advance over the 1.5-fold sequence of a poodle published by Celera in 2003. The dog is now a front-line model for the discovery of disease genes, for gene annotation, and for probing the evolutionary roots of our mammalian origins. The Dog and Its Genome, edited by Elaine Ostrander, Urs Giger and Kerstin Lindblad-Toh, celebrates the completion of the dog sequence with 26 chapters on the genomic biology of man's best friend.

The book should appeal to dog fanciers, to genome biologists who wonder about the sequence's applications, and to students of comparative genomics. It presents well written and concise discussions of the history of dog breeds — there are generally estimated to be between 350 and 1,000, of which the American Kennel Club recognizes about 150 that do not exchange genes. As many as 20 breeds were developed by 1750, increasing to 76 by 1905. Yet the domestication of dogs can be traced back 14,000 years on the evidence of archaeological remains, maybe even 40,000 years based on molecular comparisons with wolves. Clearly, dogs are the oldest domesticated species, as detailed in two of the book's chapters, and the phylogenetic ancestry of dog breeds is described in three chapters.

Years from now, as dog genomics matures, this volume will be remembered as the starting point, with vivid pieces on the vast phenotypic variation described for dogs. The latest interpretation of dog genome status is presented for experts and aficionados alike. The remarkable history of inbreeding has led to a mosaic genome of alternating homozygous and heterozygous/polymorphic segments specific for each breed; these are particularly useful for linkage disequilibrium-based association mapping of complex or multifactorial traits.

And dogs certainly have complex traits, notably the vast morphologic variation found in dog breeds as disparate as the chihuahua and the great dane. Dogs also have hard-wired behavioural acumen that allow them to herd livestock, locate missing persons and even sniff out human cancers at early stages. And of course they are loving companions like no other animals.

Generations of veterinary clinicians have identified nearly 500 human hereditary disease homologues in dogs, nearly all breed-specific; the 50 reviewed here have a confirmed genetic basis. Several have been treated successfully with futuristic gene-therapy protocols that should whet the appetite of the medical community. The book describes a cancer registry that documents the incidence and pathologies of a dozen neoplasms that account for 23% of deaths in the 65 million pet dogs in the United States. The challenge now will be to use the genome to detail the genetic bases of behaviours, morphological breed distinctiveness and the disposition of breed-specific cancers.

Researchers already have ‘bibles’ that define gene-based phenotypes suitable for interrogation by mouse, rat, fruitfly and human genetics. The Dog and Its Genome does the same for the canine genomics community. It should be consumed by researchers and their students quickly before forthcoming advances render it dated on their bookshelves.