Genetic variability of Pantaneiro horse using RAPD-PCR markers

Abstract

-Blood samples were collected from Pantaneiro Horses in five regions of Mato Grosso do Sul and Mato Grosso States. Arabian, Mangalarga Marchador and Thoroughbred were also included to estimate genetic distances and the existing variability among and within these breeds by RAPD-PCR (Random Amplified Polymorphic DNA -Polymerase Chain Reaction) molecular markers. From 146 primers, 13 were chosen for amplification and 44 polymorphic bands were generated. The analysis of molecular variance (AMOVA) indicated that the greatest portion of detected variability was due to differences between individuals within populations (75.47%). Analysis of the genetic variability between pairs of populations presented higher estimates for the five Pantaneiro populations with the Arabian breed, while lowest estimates were presented by pairs formed among the Pantaneiro populations with the Mangalarga Marchador. Highest genic diversity was shown by the Pantaneiro (0.3396), which also showed highest genetic distance with the Arabian and lowest with Mangalarga Marchador breed. UPGMA dendrogram showed distinct differences between naturalized (Pantaneiro and Mangalarga Marchador) and exotic (Arabian and Thoroughbred) breeds. In the dendrogram generated by UPGMA method, the similarity matrix generated by the Jaccard coefficient showed distinction between the naturalised breeds, Pantaneiro and Mangalarga Marchador, and the exotic breeds, Árab and English Thoroughbred. Results suggest that the Pantaneiro presents a higher genetic variability than the other studied breeds and has a close relationship with the Mangalarga Marchador.Key Words: AMOVA, Arabian, English Thoroughbred, genetic diversity, genetic resource, Mangalarga Marchador Variabilidade genética do cavalo Pantaneiro utilizando marcadores RAPD-PCRRESUMO -Amostras de sangue foram coletadas de cavalos Pantaneiros de cinco regiões dos estados de Mato Grosso do Sul e Mato Grosso. As raças Mangalarga Marchador, Árabe e Puro-Sangue Inglês (PSI) usando marcadores moleculares RAPD-PCR (Random Amplified Polymorphic DNA -Polymerase Chain Reaction) foram incluídas no intuito de se calcular as distâncias genéticas e comparar a variabilidade genética entre e dentro de cada uma das raças. Dos 146 primers escrutinados, 13 foram escolhidos para amplificação com cada um dos indivíduos das oito populações, gerando um total de 44 bandas polimórficas. Os resultados encontrados na Análise de Variância Molecular (AMOVA) indicam que grande parte da variabilidade genética detectada se deve a diferenças entre indivíduos dentro de populações (75,47%). Na análise da estimativa dos percentuais de variabilidade genética entre pares de populações, foram observados maiores valores para os pares formados entre as cinco populações de cavalo Pantaneiro e a raça Árabe, enquanto os menores percentuais ocorreram entre Pantaneiro e Mangalarga Marchador. Maior índice de diversidade gênica foi observado na raça Pantaneiro (0,3396). No dendrograma gerado pelo método UPGMA, a partir da matriz de similaridade obtida p...

Genetic variability in local Brazilian horse lines using microsatellite markers

“…AMOVA showed that 12.37% (P < 0.001) of the total genetic variance was between breeds (Table 4), similar to those found by Paiva et al (2005) for sheep breeds and Egito et al (2007) for cattle breeds in Brazil. These results showed that a reasonable genetic variability exists among the studied breeds when compared with other authors (Jordana, et al, 1999;Zabek et al, 2005).…”

“…The importance of naturalized horse breeds in Brazil has been shown in several studies. Silva et al (2005) found that the Pantaneira horse was better adapted to its environment than exotic breeds in daily management of cattle, and Egito et al (2007) conducted the first study with RAPD markers in herds of the Pantaneira horse.…”

“…With K = 7, all seven genetic groups are correctly identified. Here the genetic uniqueness of each group is seen, which suggested a reduced gene flow between them, unlike other studies with conservation animals in Brazil (ex., Egito et al, 2007;Sollero et al, 2009). Based on this analysis, all breeds were well-defined genetic entities meaning that their entrance in the conservation program is vital for the continued maintenance of valuable genetic variability for traits linked to disease and heat resistance and tolerance.…”

“…While some breeds have highly active Breeder's Associations (the Pantaneira breed, for example), others are maintained in conservation nuclei by EMBRAPA. Some information is available on morphological data on these breeds (Cabral et al, 2004a,b;McManus et al, 2005McManus et al, , 2008 or from low information content RAPD markers that do not allow comparative analyses across independent studies (Egito et al, 2007).…”

D-loop haplotype diversity in Brazilian horse breeds

“…In addition, it is important to note that EPA is the most prominent locally adapted breed in Brazil, and it has a growing trend in the internal market. Such high genetic variability was also observed in other studies using RAPD ( Egito et al , 2007 ) and microsatellite markers ( Giacomoni et al , 2008 ; Sereno et al , 2008 ).…”