Caracterização molecular de animais da raça Nelore utilizando microssatélites e genes candidatos

Abstract

RESUMO -No presente trabalho, 180 fêmeas da raça Nelore, provenientes de oito rebanhos, foram analisadas quanto aos marcadores microssatélites TEXAN15, BM1224 e CSFM50 e aos polimorfismos de comprimento de fragmentos de restrição (RFLP) nos locos κ-caseína, β-lactoglobulina e hormônio de crescimento (GH). Com exceção de GH, todos os marcadores foram polimórficos na amostra estudada. Os valores de heterozigosidade, diversidade gênica, conteúdo de informação polimórfica (PIC) e probabilidade de exclusão de paternidade (PE) foram estimados. Os maiores valores de PIC (0,685) e PE (0,521) foram obtidos para o marcador BM1224.Palavras-chave: bovino, DNA, marcador, microssatélite, Nelore, RFLP Molecular Characterization of a Nellore Beef Cattle Sample Using Microsatellites and Candidate GenesABSTRACT -In the present work, 180 Nellore females from eight herds were analyzed for TEXAN15, BM1224 and CSFM50 microsatellites and for the restriction fragments polymorphism (RFLP) at the locos κ-casein, β-lactoglobulin and growth hormone (GH). Excepted for GH, all markers were polymorphic in the studied sample. The values of heterozigozity, gene diversity, polymorphic information content (PIC) and paternity exclusion probability (PE) were estimated. The highest PIC (0.685) and PE (0.521) values were obtained for microsatellite BM1224.Key Words: bovine, DNA, marker, microsatellite, Nelore, RFLP 1 Departamento de Genética e Evolução -UFSCar, São Carlos -SP. E.mail: jtalhari@terra.com.br; matamb@terra.com.br 2 EMBRAPA -CPPSE, São Carlos, SP. E.mail: mauricio@cppse.embrapa.br; tambasco@zaz.com.br; luciana@cppse.embrapa.br 3 Departamento de Produção Animal -ESALQ, Piracicaba -SP. E.mail: llcoutin@carpa.ciagri.usp.br IntroduçãoDevido a sua importância econômica e cultural, estudos das relações genéticas entre rebanhos bovinos têm sido, historicamente, uma área ativa da sistemá-tica biológica. A caracterização de determinada raça pode ser feita por suas propriedades fenotípicas, morfológicas e fisiológicas, origem, habitat, distribuição geográfica, produção e parâmetros genéticos

Genetic variability of 10 microsatellite markers in the characterization of Brazilian Nellore cattle (Bos indicus)

“…To date, there are no reports of studies on Nellore cattle indicating the presence of null alleles for the markers analyzed, although the presence of null alleles has previously been observed in segregation analyses using other microsatellite loci in Nellore cattle (Tambasco et al, 2000). This hypothesis cannot be excluded because segregation analysis using the loci evaluated in this study has not yet been undertaken for Nellore cattle.…”

Genetic Variants and Allele Frequencies of Kappa Casein in Egyptian Cattle and Buffalo Using PCR-RFLP

“…Some events, such as an accumulation of some genotypes, subdivision of the population, mutation, selection, migration, or endogamy can result in a state of disequilibrium within the population (Tambasco et al, 2000;Vasconcellos et al, 2003). Both cattle breeds were deviated from equilibrium which may be due to migration or subdivision.…”

Genetic polymorphism of the kappa-casein gene in Brazilian cattle

“…A population is considered to be in Hardy-Weinberg equilibrium when the allelic (p and q) and genotypic (p 2 , 2pq and q 2 ) frequencies remain constant from one generation to the next, due to a random association of gametes. According to Tambasco et al (2000) and Vasconcellos et al (2003), some events, such as an accumulation of some genotypes, subdivision of the population, mutation, selection, migration, or endogamy, can result in a state of disequilibrium within the population. All breeds and genetic groups were found to be in Hardy-Weinberg equilibrium ( Table 2), suggesting that the κ-Cn gene was not influenced by selection.…”