Canid genomics: Mapping genes for behavior in the silver fox

Domestication is the condition and/or process of genetically and environmentally induced developmental adaptation to man and captivity (Price 1984). Several trends are commonly observed in domesticated animals. Most notable are the changes in morphology including pigmentation, size, and relative skeletal proportion (Belyaev 1969; Price 1984). These may be hugely divergent between domestic animals and their progenitor counterparts (Belyaev 1969, 1979; Price 1984; Trut 1999, 2001). Domestication is also associated with marked changes in reproductive physiology, accelerated sexual maturity, increased fecundity, loss of reproductive seasonality, and longer periods of reproductive receptivity. However, it is the behavioral adaptations associated with domestication that are the most dramatic and that have most captured our attention. Domestic animals are said to be “tame”, responding to humans in a less-aggressive, often even affable manner. Humans form bonds and often develop lifelong relationships with domestic animals, frequently becoming valued members of the family community. Using the resources presented by Kukekova et al. in this issue of Genome Research, we take a giant step forward in our ability to localize the genes controlling the process of domestication in the canine system (Kukekova et al. 2007).

Kukekova et al. (2007) have published the first meiotic linkage map of the silver fox (Vulpes vulpes), which is a color variant of the red fox. It last shared a common ancestor with the domestic dog (Canis familiaris) ∼10–12 million years ago (Vila et al. 1999a). A colony of silver foxes has been established at the Institute for Cytology and Genetics (ICG) at the Russian Academy of Sciences in Novosibirsk, Russia, with the purpose of developing lines of animals suitable for studying the genetics of domestication. The animals have been selectively bred for nearly half a century for one of the key components to domestication, tame …