Dissection of ancestral genetic contributions to Creole goat populations

Abstract

Goats have played a key role as source of nourishment for humans in their expansion all over the world in long land and sea trips. This has guaranteed a place for this species in the important and rapid episode of livestock expansion triggered by Columbus' arrival in the Americas in the late 1400s. The aims of this study are to provide a comprehensive perspective on genetic diversity in American goat populations and to assess their origins and evolutionary trajectories. This was achieved by combining data from autosomal neutral genetic markers obtained in more than two thousand samples that encompass a wide range of Iberian, African and Creole goat breeds. In general, even though Creole populations differ clearly from each other, they lack a strong geographical pattern of differentiation, such that populations of different admixed ancestry share relatively close locations throughout the large geographical range included in this study. Important Iberian signatures were detected in most Creole populations studied, and many of them, particularly the Cuban Creole, also revealed an important contribution of African breeds. On the other hand, the Brazilian breeds showed a particular genetic structure and were clearly separated from the other Creole populations, with some influence from Cape Verde goats. These results provide a comprehensive characterisation of the present structure of goat genetic diversity, and a dissection of the Iberian and African influences that gave origin to different Creole caprine breeds, disentangling an important part of their evolutionary history. Creole breeds constitute an important reservoir of genetic diversity that justifies the development of appropriate management systems aimed at improving performance without loss of genomic diversity.

Local Goat Breeds in the United States

“…The approach of evaluating goats by this external phenotype has been validated by DNA testing, revealing that this phenotype, which occurs throughout the Americas, does reflect an underlying genotypic similarity. This indicates that the history and development of this type of goat traces back to a common foundation centuries ago [5,6].…”

“…Research is now documenting that Spanish goats are generally superior to Boer goats in overall productivity measured on a herd-wide basis, and are on a par with Kiko goats [5,6]. This documentation points to the need to carefully evaluate local resources before replacing them with exotic resources, because local resources may indeed be equal or superior due to environmental adaptation.…”

Conservation Strategies for Local Breed Biodiversity

“…Once the breed was defined and described, it was possible to do DNA evaluation across several of the founding lines of the breed [8,12]. The results of this effort validated the fact that this external phenotype, which is spread throughout the Americas, shares the genetic evidence expected of a common foundation centuries ago.…”

“…The histories of many groups of landraces, such as the Criollo breeds of the Americas, have a collective origin in a limited source (Iberia and Africa in this case) that can help drive assessment and conservation decisions [5]. In the case of limited foundation events, such as is typical of island populations, subsequent genetic drift can further influence the final genome of the population [8].…”

Organization and Management of Conservation Programs and Research in Domestic Animal Genetic Resources

“…Its first findings were related to the genetic relationships between Brazilian and Portuguese goat breeds using microsatellite marker information [94]. Afterward, the consortium studied the population structure of Ibero-American native breeds achieving their primary characterization [95], but also the genetic relationship among Ibero-American goat breeds and their Iberian potential ancestors [96].…”