Research Article

Genetic diversity in the Pantaneiro horse breed assessed using microsatellite DNA markers

Published: March 18, 2008
Genet. Mol. Res. 7 (1) : 261-270 DOI: https://doi.org/10.4238/vol7-1gmr367
Cite this Article:
E.H. Giacomoni, G.P. Fernández-Stolz, T.R.O. Freitas (2008). Genetic diversity in the Pantaneiro horse breed assessed using microsatellite DNA markers. Genet. Mol. Res. 7(1): 261-270. https://doi.org/10.4238/vol7-1gmr367
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Abstract

The genetic variability for a sample of 227 animals from three populations of Pantaneiro horses was estimated using data from 10 microsatellite loci. The number of alleles and the proportion of heterozygosity indicated high variability. A total of 91 alleles were found, with a significantly high mean number of alleles. The mean polymorphic information content was 0.7 and the paternity exclusion probability was 99.3%. The inbreeding coefficient (Fis) was low for the three populations: Ipiranga (FIS = 0.147), Nova Esperança (Fis = 0.094) and Promissão (Fis = 0.108). Genetic differentiation among all three populations was low (FST = 0.008 to 0.064). Three methods were used to test for a recent bottleneck effect. The graphical method and the Wilcoxon test using the stepwise mutation model showed no bottleneck pattern for any of the populations. The test by two-phase mutation model showed genetic signatures of bottleneck for Ipiranga and Promissão. When we consider standard deviation value for Nova Esperança, the M-statistic detected a bottleneck pattern, but this result could be explained by a sample size effect. Therefore, there is no immediate cause for concern regarding loss of variation within the breed.

The genetic variability for a sample of 227 animals from three populations of Pantaneiro horses was estimated using data from 10 microsatellite loci. The number of alleles and the proportion of heterozygosity indicated high variability. A total of 91 alleles were found, with a significantly high mean number of alleles. The mean polymorphic information content was 0.7 and the paternity exclusion probability was 99.3%. The inbreeding coefficient (Fis) was low for the three populations: Ipiranga (FIS = 0.147), Nova Esperança (Fis = 0.094) and Promissão (Fis = 0.108). Genetic differentiation among all three populations was low (FST = 0.008 to 0.064). Three methods were used to test for a recent bottleneck effect. The graphical method and the Wilcoxon test using the stepwise mutation model showed no bottleneck pattern for any of the populations. The test by two-phase mutation model showed genetic signatures of bottleneck for Ipiranga and Promissão. When we consider standard deviation value for Nova Esperança, the M-statistic detected a bottleneck pattern, but this result could be explained by a sample size effect. Therefore, there is no immediate cause for concern regarding loss of variation within the breed.