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Recombination is not the main cause of phenotypic differences between domestic and wild species

Morphological and physiological diversity observed in domestic species is strikingly greater than that seen in wild species. To explain this diversity, a hypothesis was proposed some decades ago that suggested that selective forces imposed on domestic species (plants and animals) would have led to higher recombination rate in the genome of domesticates, thus allowing for new combinations of alleles, and thus also of characters. However, this hypothesis had never been conclusively tested. Using immunolabeling techniques applied to reproductive tissue (spermatocytes), recombination rate was measured in three pairs of closely related domestic and wild species: dog and wolf, goat and ibex, sheep and mouflon. Recombination rate was higher in the wild than in the domestic species, contrary to the initial hypothesis. Alternatively, it was possible that recombination rate was increased around genes of obvious phenotypic effect in domestic species (colour, size, head shape, behaviour...), preferentially selected around these regions, since humans started domesticating species, thousands of years ago. A genomic analysis comparing dogs and wolves showed no differences in the distribution of recombination events. These results suggest that the great diversity observed in domestic animals is not the consequence of significant changes in recombination rate or patterns. Currently, the scientific community strives to understand what mechanisms may be operating to generate the striking forms and shapes exhibited by domestic species. informacion[at]ebd.csic.es Muñoz-Fuentes et al (2014) Strong artificial selection in domestic mammals did not result in an increased recombination rate. Mol. Biol. Evol. 32(2):510–523 doi:10.1093/molbev/msu322


http://mbe.oxfordjournals.org/content/early/2014/11/19/molbev.msu322
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