title: Genetic variability in local Brazilian horse lines  using microsatellite markers.
abstract: Genetic variability at 11 microsatellite markers was  analyzed in five naturalized/local Brazilian horse breeds or genetic groups.  Blood samples were collected from 328 animals of the breeds Campeira (Santa  Catarina State), Lavradeira (Roraima State), Pantaneira (Pantanal  Mato-Grossense), Mangalarga Marchador (Minas Gerais State), as well as the  genetic group Baixadeiro (Maranhão State), and the exotic breeds English  Thoroughbred and Arab. We found significant genetic variability within  evaluated microsatellite loci, with observed heterozygosis varying between  0.426 and 0.768 and polymorphism information content values of 0.751 to 0.914.  All breeds showed high inbreeding coefficients and were not in Hardy-Weinberg  equilibrium. The smallest genetic distance was seen between the Pantaneira and  Arab breeds. The principal component analyzes and Bayesian approach  demonstrated that the exotic breeds have had a significant influence on the  genetic formation of the local breeds, with introgression of English  Throroughbred in Pantaneira and Lavradeira, as well as genetic proximity  between the Arab, Pantaneira and Mangalarga Marchador populations. This study  shows the need to conserve traits acquired by naturalized horse breeds over  centuries of natural selection in Brazil due to the genetic uniqueness of each  group, suggesting a reduced gene flow between them. These results reinforce the  need to include these herds in animal genetic resource conservation programs to  maximize the genetic variability and conserve useful allele combinations.
authors.affiliation: Laboratório de Genética Animal, Embrapa Recursos Genéticos e Biotecnologia, Brasília, DF, Brasil.
authors.forename: A C M
authors.initials: AC
authors.lastname: Silva
authors.forename: S R
authors.initials: SR
authors.lastname: Paiva
authors.forename: M S M
authors.initials: MS
authors.lastname: Albuquerque
authors.forename: A A
authors.initials: AA
authors.lastname: Egito
authors.forename: S A
authors.initials: SA
authors.lastname: Santos
authors.forename: F C
authors.initials: FC
authors.lastname: Lima
authors.forename: S T
authors.initials: ST
authors.lastname: Castro
authors.forename: A S
authors.initials: AS
authors.lastname: Mariante
authors.forename: P S
authors.initials: PS
authors.lastname: Correa
authors.forename: C M
authors.initials: CM
authors.lastname: McManus
mesh_terms: D000818:Animals; D001483:Base Sequence; D001938:Brazil; D005819:Genetic Markers; D014644:Genetic Variation; D006579:Heterozygote; D006736:Horses / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction
chemical_list: D005819:Genetic Markers