Goat domestication and breeding: a jigsaw of historical, biological and molecular data with missing pieces

Abstract

Domestic goats (Capra hircus) are spread across the five continents with a census of 1 billion individuals. The worldwide population of goats descends from a limited number of bezoars (Capra aegagrus) domesticated 10 000 YBP (years before the present) in the Fertile Crescent. The extraordinary adaptability and hardiness of goats favoured their rapid spread over the Old World, reaching the Iberian Peninsula and Southern Africa 7000 YBP and 2000 YBP respectively. Molecular studies have revealed one major mitochondrial haplogroup A and five less frequent haplogroups B, C, D, F and G. Moreover, the analysis of autosomal and Y-chromosome markers has evidenced an appreciable geographic differentiation. The implementation of new molecular technologies, such as whole-genome sequencing and genome-wide genotyping, allows for the exploration of caprine diversity at an unprecedented scale, thus providing new insights into the evolutionary history of goats. In spite of a number of pitfalls, the characterization of the functional elements of the goat genome is expected to play a key role in understanding the genetic determination of economically relevant traits. Genomic selection and genome editing also hold great potential, particularly for improving traits that cannot be modified easily by traditional selection.

Phylogeny and distribution of Y-chromosomal haplotypes in domestic, ancient and wild goats

“…However, these haplotypes are based on a low number of SNPs in or near DBY-1, SRY and ZFY. Thus, it is not clear if the haplotypes represent major haplogroups or local variants, if other major haplogroups exist, and which of the Y-chromosomal variants already existed in the earlier domestic goats and in their wild ancestor, the bezoar (Amills et al, 2017).…”

Animal Domestication: A Brief Overview

“…The wild ancestor of goat is the bezoar, Capra aegagrus [40,42,49]. The first archaeological evidence of goat domestication traces back in the Fertile Crescent about 10,000 years ago [42,49,71]. A large-scale analysis of current bezoar mitochondrial DNA (mtDNA) polymorphism over its whole geographic distribution suggested that the domestication process occurred over a very large area encompassing eastern Anatolia and North-West Iran [50].…”

“…A large-scale analysis of current bezoar mitochondrial DNA (mtDNA) polymorphism over its whole geographic distribution suggested that the domestication process occurred over a very large area encompassing eastern Anatolia and North-West Iran [50]. Additional primary centers of goat domestication, including the Indus Valley, Southern Levant, and China, have not been convincingly demonstrated yet [71]. Analysis of the goat mitochondrial DNA polymorphism of the main haplogroup (representing more than 90% of the haplotypes) strongly supports the absence of bottleneck at the domestication time in goats [50].…”

“…Besides, goat mtDNA polymorphism also suggests high historical gene flow among continents, which already occurred during the Neolithic expansion into Europe [49]. The extraordinary adaptability and hardiness of goats favored their rapid spread over the Old World [71]. Goats have successfully adapted to desert, mountainous, and tropical areas where other livestock species would not thrive [71].…”

“…The extraordinary adaptability and hardiness of goats favored their rapid spread over the Old World [71]. Goats have successfully adapted to desert, mountainous, and tropical areas where other livestock species would not thrive [71]. Between the fifteenth and eighteenth centuries, goats were transported to America and Oceania [71].…”