Resumo: Em mamíferos, incluindo os eqüinos (Equus caballus), o gene protein kinase, AMP-activated, gamma 3 non-catalytic subunit (PRKAG3) encontra-se relacionado ao desempenho muscular, os genes cysteine-rich secretory protein 1 (CRISP1) e spermatogenesis associated 1 (SPATA1) à fertilidade de machos e os genes 5-hydroxytryptamine (serotonin) receptor 1A (HTR1A) e solute carrier family 6 (neurotransmitter transporter, serotonin), member 4 (SLC6A4) ao temperamento. Os objetivos deste trabalho foram a padronização de metodologia alternativa de genotipagem por PCR-RFLP dos SNPs AY_376689:c.773C>T, AJ_315378:c.110A>G e AB_264325:c.771G>C dos genes eqüinos PRKAG3, CRISP1 e HTR1A, respectivamente, bem como a caracterização em cavalos da raça brasileira Mangalarga destes e de outros polimorfismos, o AAWR_02017454:g.121684T>C do gene SPATA1 e o AB_098561:c.1470G>A do gene SLC6A4, a fim de promover o embasamento necessário para futuras pesquisas visando associação entre marcadores de DNA e características de interesse na raça. Foram utilizados 151 animais Mangalarga, de ambos os sexos e de idades variadas, representativos da população do Estado de São Paulo. O método de PCR-RFLP mostrou-se adequado para a genotipagem dos SNPs AY_376689:c.773C>T do PRKAG3, AJ_315378:c.110A>G do CRISP1 e AB_264325:c.771G>C do HTR1A. Entretanto, os polimorfismos do PRKAG3 e CRISP1 provavelmente não ocorrem na Mangalarga, impossibilitando estudos de associação com os marcadores. As estimativas dos parâmetros genético-populacionais obtidas para o polimorfismo AAWR_02017454:g.121684T>C do gene SPATA1 na amostra estudada demonstraram a possibilidade de realização de pesquisas visando a sua associação com fertilidade de machos. As mesmas estimativas obtidas para os polimorfismos AB_264325:c.771G>C do HTR1A e o AB_098561:c.1470G>A do SLC6A4 desencorajam a realização de pesquisas visando suas associações à características relacionadas ao temperamento / Abstract: In mammals, including the equine (Equus caballus), the protein kinase, AMP-activated, gamma 3 non-catalytic subunit (PRKAG3) gene is related to muscular development, the cysteine-rich secretory protein 1 (CRISP1) and spermatogenesis associated 1 (SPATA1) genes are related to male fertility and the 5-hydroxytryptamine (serotonin) receptor 1A (HTR1A) and solute carrier family 6 (neurotransmitter transporter, serotonin), member 4 (SLC6A4) genes are related to temperament. The aims of the present study were to propose an alternative genotyping method for the AY_376689:c.773C>T, AJ_315378:c.110A>G and AB_264325:c.771G>C SNPs of the equine PRKAG3, CRISP1 and HTR1A genes, respectively, as well as the characterization in Mangalarga Brazilian breed horses of these and other polymorphisms, the AAWR_02017454:g.121684T>C of the SPATA1 gene and the AB_098561:c.1470G>A of the SLC6A4 gene, in order to provide the necessary basis for future research towards associating the DNA markers and traits of interest in this breed. For this, 151 Mangalarga animals were used, from both sexes and random ages, representing the São Paulo state population. The PCR-RFLP methodology was found to be adequate for the genotyping of the SNPs AY_376689:c.773C>T of the PRKAG3, AJ_315378:c.110A>G of the CRISP1 and AB_264325:c.771G>C of the HTR1A. Nevertheless, the PRKAG3 and CRISP1 polymorphisms probably do not occur in Mangalarga, making it impossible the association studies with these markers. The estimative of the population genetic parameters obtained for the AAWR_02017454:g.121684T>C polimorphism of the SPATA1 gene in the sample studied showed the possibility of carrying out research towards its association with male fertility. On the other hand, the same estimatives obtained for the polymorphisms AB_264325:c.771G>C of the HTR1A and AB_098561:c.1470G>A of the SLC6A4 discourage research towards their association to traits related to temperament / Orientador: Marcílio Dias Silveira da Mota / Coorientador: Rogério Abdallah Curi / Banca: Humberto Tonhati / Banca: Evaldo Antonio Lencioni Titto / Mestre