Key genes involved in domestication

Abstract

Abstract Domestication is a process that involves the interaction of human with animals in which the genotype of the domesticated species adapts to the conditions provided by humans. The number of domesticated species is very small compared to all animal diversity implying that there are genetic obstacles to domesticate a species. In addition, domesticated animals share several characteristics that differentiate them from their wild relatives in terms of behaviour and morphology. These similarities can be due to similar selective forces acting during domestication and also because the same genetic components were affected during domestication. With the aim to identify which are the key genes that are involved in the domestication of several species and why some species were never domesticated, I reviewed several aspects of domestication such as how it proceeds, which characteristics favour this process if it is possible to reverse the domestication process and which genetic changes are responsible of the differences in morphology and behaviour. In general, domestication is a fast process that requires a few generations and for this reason; it is possible that the changes in the expression of a few genes are causing major changes in other genes involved different regulatory mechanisms. The process of domestication can be reversed at some extent and it depends on the degree of change that happened during domestication. The species can express again their wild behaviour, in some cases with previous conditioning, but some changes in the phenotype are not possible to be reversed. The reason of why some animals have never been domesticated has been attributed to the lack of characteristics that enhance the interaction with humans and their breeding schemes, such a high levels of aggressiveness and long live spacing. However, little is known of which are the major genetic constrains for domestication. On the other hand, several genes have been identified to differ between domesticated species and their wild relatives they are mainly related with reproduction, levels of aggressiveness, anxiety and stress responses. Other genes that have been found to differ between domesticated species with their wild relatives include genes that code for coat coloration, retention of juvenile characteristic and adaptation to the diet. However, these genes are a likely to have changed once the species were domesticated or as a consequence of indirect selection over them, in which the changes in the genes that favoured the animal domestication favoured their change.