Genetic diversity of Brazilian Pantaneiro horse and relationships among horse breeds

Fabiana Tavares Pires De Souza Sereno,Jose Luis Vega-Pla,Juan Vicente Delgado Bermejo,José Robson Bezerra Sereno,Lucy Kelly

doi:10.1590/s0100-204x2008000500007

Fabiana Tavares Pires De Souza Sereno, Jose Luis Vega-Pla + Show 3 more

Open Access

https://doi.org/10.1590/s0100-204x2008000500007

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Abstract

The objective of this work was to evaluate the genetic diversity of Brazilian Pantaneiro horse by microsatellite markers, investigate the effect of genetic bottlenecks and estimate genetic differentiation among four horse breeds. Genetic variation was estimated through allele frequencies and mean breed heterozygosity. Nei's genetic distances among the breeds Pantaneiro, Thoroughbred, Arabian, Spanish Pure Breed (Andalusian), and Uruguay Creole were calculated, and it was used to construct an UPGMA dendrogram. Clustering at different K values was calculated to infer population structure and assign individuals to populations. Nei's distances showed a minimum distance between Pantaneiro horse and Spanish Pure Breed (0.228), and similar distances from Spanish Pure Breed to Thoroughbred and to Arabian (0.355 and 0.332). It was observed a great level of diversity, clear distance from Pantaneiro horse to other breeds, and genetic uniformity within breed. It was verified a certain level of substructure of Pantaneiro horse showing no influences from the other studied breeds.

Highlights

The wide use and conservation of Pantaneiro horse, bred in Brazilian Pantanal, was based in its functional ability to work with cattle, and its adaptation to harsh environmental conditions
Twelve microsatellite markers recommended by the Equine Genetics and Thoroughbred Parentage Testing Standardization Committee of the International Society for Animal Genetics (ISAG) (Hoffmann et al, 2004), with known positions, were used in this work (Table 1)
The greater number of alleles in Pantaneiro horse may be a consequence of strategies, such as selection and use of different stallions, adopted by the breeding nucleus to prevent inbreeding and preserve genetic variation within the population

Summary

Introduction

The wide use and conservation of Pantaneiro horse, bred in Brazilian Pantanal, was based in its functional ability to work with cattle, and its adaptation to harsh environmental conditions. Within the framework of breed conservation, genetic characterization is important in guarding breed integrity. Genetic characterization is the first step in breed conservation and may have implications for future breeding strategies. Ease and accuracy of typing, together with high levels of polymorphism and spread distribution in the genome, make microsatellite loci an attractive potential source of information about population histories and evolutionary processes (Goldstein & Schlötterer, 1999). Microsatellites are considered suitable for biodiversity evaluation, owing to their codominant inheritance, high heterozygosity, ease and reliability of scoring, ubiquitous presence throughout the genome and high degree of polymorphism (Takezaki & Nei, 1996). Pantaneiro breed was genetically characterized by red blood cell alloantigen, blood group loci and biochemical genetic loci (Cothran et al, 1998)

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