The Genomic Makeup of Nine Horse Populations Sampled in the Netherlands.

Schurink Schurink,Ducro Ducro,Shrestha Shrestha,Bosse Bosse,Eriksson Eriksson,Bovenhuis Bovenhuis,Back Back,Johansson Johansson

doi:10.3390/genes10060480

Abstract

The spectrum of modern horse populations encompasses populations with a long history of development in isolation and relatively recently formed types. To increase our understanding of the evolutionary history and provide information on how to optimally conserve or improve these populations with varying development and background for the future, we analyzed genotype data of 184 horses from 9 Dutch or common horse populations in the Netherlands: The Belgian draft horse, Friesian horse, Shetland pony, Icelandic horse, Gelder horse, Groninger horse, harness horse, KWPN sport horse and the Lipizzaner horse population. Various parameters were estimated (e.g., runs of homozygosity and FST values) to gain insight into genetic diversity and relationships within and among these populations. The identified genomic makeup and quantified relationships did mostly conform to the development of these populations as well as past and current breeding practices. In general, populations that allow gene-flow showed less inbreeding and homozygosity. Also, recent bottlenecks (e.g., related to high selective pressure) caused a larger contribution of long ROHs to inbreeding. Maintaining genetic diversity through tailor-made breeding practices is crucial for a healthy continuation of the investigated, mostly inbred and (effectively) small sized horse populations, of which several already experience inbreeding related issues.

Highlights

In horses, genetic diversity is predominantly observed between breeds or types, where little variation is present within breeds [1]
The highest mean inbreeding coefficients were observed in the Friesian horse and Shetland pony populations
The lowest mean inbreeding coefficients were observed in the KWPN sport horse and Groninger horse populations (Table 2)

Summary

Introduction

Genetic diversity is predominantly observed between breeds or types, where little variation is present within breeds [1]. The horse probably has the greatest diversity in purposes of all domesticated animal species and has had a large impact on the civilization of humans. Horses were a food source and later used for transportation, draft power, agricultural work, hunting and warfare [2]. Most of these historical purposes are still performed by horses in some part of the world [3]. In addition to these different purposes, the evolution from the domesticated founding

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Conclusion