Frequências alélicas e genotípicas para beta-caseína do leite em bovinos leiteiros da microrregião de Araguaína, Tocantins

• Autor(a) principal: Oliveira, Rodolfo Olinto Rotoli Garcia
• Data de Publicação: 2021
• Outros Autores: Carvalho, Minos Esperandio de, Rodrigues, Matheus Henrique Dias, Poleti, Mirele Daiana, Ferraz, José Bento Sterman, Souza, Ana Beatriz Bezerra, Minharro, Silvia, Santos, Helcileia Dias, Ferreira, Jorge Luís
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Veterinary Research and Animal Science
• Texto Completo: https://www.revistas.usp.br/bjvras/article/view/186603
• topic: Beta-casein; Dairy cattle; Genotyping; Tocantins; Beta-caseina; Bovino de leite; Genotipagem; Tocantins

At present, there is a concern about the quality of milk and diseases related to its consumption, as it can generate discomfort and allergic reactions in some individuals due to its protein components. Thus, the present study was developed to identify the allele and genotype frequencies of genes for β casein, A1 and A2, in dairy herds in the region of Araguaína-TO, Brazil. Genetic material from 421 animals (crossbred dairy cattle in lactation) was used. All animals were numbered for identification, and DNA samples were extracted from hair bulbs. Samples for two markers from the polymorphic regions were characterized and confirmed by real time PCR using the ABI Prism® 7500 Sequence Detection System (Applied Biosystems). Allele and genotype frequencies were determined using the TaqMan™ detection system, where the primer and probe release different fluorescence signals for each allele of the polymorphism. The sampled herd showed frequencies of 28.27% for the A1 allele and 71.73% for the A2 allele. Genotype frequencies were 52.96% (223/421) for A2A2; 37.53% (158/421) for the A1A2 genotype; and 9.50% (40/421) for the A1A1 genotype. The frequency of the A1 allele for β-casein in dairy herds from the northern region of Tocantins was low and is per the results of previous studies. Although the A2A2 genotype of β-casein had a high relative frequency, the A1A2 genotype is still rather frequent, warranting greater selection pressure.