According to genetic researchers headed by Prof Leif Andersson of Texas A&M University, Uppsala University and Swedish University of Agricultural Sciences, the genes responsible for the development of the brain and the nervous system were important for domestication of the wild rabbit.
The European rabbit, Oryctolagus cuniculus. Image credit: J.J. Harrison / CC BY-SA 3.0.
Scientists believe domestication of the rabbit was initiated in monasteries in southern France around 600 CE, because the Catholic Church had declared that young rabbits were not considered meat, but fish, and could therefore be eaten during Lent.
At this time, the wild ancestor, the European rabbit (Oryctolagus cuniculus), was mostly restricted to the Iberian Peninsula and southern France, where three subspecies occurred.
The genetic changes underlying the initial steps of its domestication have been poorly understood – until now.
Prof Andersson and his colleagues generated a high-quality reference genome for the rabbit and compared it to resequencing data from populations of wild and domestic rabbits.
The scientists first sequenced the entire genome of one domestic rabbit to develop a reference genome assembly.
Then, they resequenced entire genomes of domestic rabbits representing six different breeds and wild rabbits sampled from 14 different places across the Iberian Peninsula and southern France.
“No previous study on animal domestication has involved such a careful examination of genetic variation in the wild ancestral species. This allowed us to pinpoint the genetic changes that have occurred during rabbit domestication,” explained Prof Andersson, who is the senior author of the paper published in the journal Science.
The results show that the wild rabbit is a highly polymorphic species that carries gene variants that were favorable during domestication, and that the accumulation of many small changes led to the inhibition of the strong flight response.
“Wild rabbits, in contrast to domestic rabbits, have a very strong flight response because they are hunted by eagles, hawks, foxes and humans and therefore must be very alert and reactive to survive in the wild,” the scientists said.
They also revealed which genes have been altered during rabbit domestication. They were struck by the strong enrichment of genes involved in the development of the brain and the nervous system, which are among the genes particularly targeted during domestication.
“These results are exciting because they shed light on what types of genetic modifications are likely to be important during the early stages of domestication,” said study co-author Dr Jeffrey Good of the University of Montana and the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
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Miguel Carneiro et al. 2014. Rabbit genome analysis reveals a polygenic basis for phenotypic change during domestication. Science, vol. 345, no. 6200, pp. 1074-1079; doi: 10.1126/science.1253714
