Insight into the Genetic Population Structure of Wild Red Foxes in Poland Reveals Low Risk of Genetic Introgression from Escaped Farm Red Foxes.

Anna Mucha,Heliodor Wierzbicki,Magdalena Moska,Magdalena Zatoń-Dobrowolska

doi:10.3390/genes12050637

Abstract

In this study we assessed the level of genetic introgression between red foxes bred on fur farms in Poland and the native wild population. We also evaluated the impact of a geographic barrier and isolation by distance on gene flow between two isolated subpopulations of the native red fox and their genetic differentiation. Nuclear and mitochondrial DNA was collected from a total of 308 individuals (200 farm and 108 wild red foxes) to study non-native allele flow from farm into wild red fox populations. Genetic structure analyses performed using 24 autosomal microsatellites showed two genetic clusters as being the most probable number of distinct populations. No strong admixture signals between farm and wild red foxes were detected, and significant genetic differentiation was identified between the two groups. This was also apparent from the mtDNA analysis. None of the concatenated haplotypes detected in farm foxes was found in wild animals. The consequence of this was that the haplotype network displayed two genetically distinct groups: farm foxes were completely separated from native ones. Neither the River Vistula nor isolation by distance had a significant impact on gene flow between the separated wild red fox subpopulations. The results of our research indicate a low probability of genetic introgression between farm and native red foxes, and no threat to the genetic integrity of this species.

Highlights

Many wild animal populations are endangered by genetic introgression from domesticated animals that have escaped from farms [1,2,3,4,5,6,7,8]
We evaluated the impact of a geographic barrier and isolation by distance on gene flow between two native red fox subpopulations, isolated from each other by the river, and their genetic differentiation
We evaluated the impact of a geographic barrier and isolation by distance on gene flow between two nativ3eofr1e6d fox subpopulations, isolated from each other by the river, and their genetic differentiation

Summary

Introduction

Many wild animal populations are endangered by genetic introgression from domesticated animals that have escaped from farms [1,2,3,4,5,6,7,8]. Genetic introgression can be defined as the incorporation of alleles from one species into the gene pool of a second, divergent species [9]. This can lead to outbreeding depression significantly disrupting locally adapted gene complexes and to extinction by genetic replacement [10,11,12]. An increasing conservation problem is the admixture of native populations with newcomers (e.g., animals bred by humans on farms scattered across the country). In this situation, introgression is not restricted to the distributional margins, but is catalysed by spots of hybridization inside the range of a native species [17]

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