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Previous issue date: 2011-08-29 / Universidade Federal do Rio Grande do Norte / The objective of this study was to identify DNA polymorphisms at the genes leptin, β-lactoglobulin and pituitary-specific transcription factor in three genetic groups of Holstein x Guzerat dairy cows and investigate the relationship between their genotypes and the composition and quality of milk of dairy cows. Samples were collected in August 2009, being 113 blood samples from lactating crossbred cows and 58 milk samples. For analysis of DNA polymorphisms blood samples were collected, analyzed later in the Genetic Laboratory affiliated to the Zootechny Institute of S?o Paulo and individual milk samples were collected according to standards established by the laboratory of Management Program of Northeast Dairy Herds (PROGEN), at Federal Rural University of Pernambuco (UFRPE) for analysis of milk composition and quality. The characterization of genotypes was performed by PCR-RFLP, for which were designed specific primers for each studied gene and restriction enzymes Kpn2I, HaeIII and HinfI that cut the DNA of the following genes: leptin, β-lactoglobulin and a PIT, respectively. The leptin estimate genotypic frequence were CC 0.112, TT 0.225 and CT 0.661, for β-lactoglobulin were AA 0.136, AB 0.323 and BB 0.539, and for PIT were ++ 0.655, -- 0.311 and +- 0.032. The results show that the population is in Hardy-Weinberg disequilibrium for leptin, β-lactoglobulin and a PIT due to excess of heterozygotes in the population, however, as these genes are associated with the milk production it is considered that the animals have genetic potential for milk production in the Brazilian semi-arid conditions. Through the characterization of the studied herd there were not found implications of the polymorphism of leptin, β-lactoglobulin and PIT in the composition and quality of milk from cows in the different genetic groups 1/2, 3/4 and 7/8 Holstein x Guzerat.
Key words: β-lactoglobulin, crossbred cows, leptin, PCR-RFLP, PIT1, semi-arid. / O objetivo do presente estudo ? identificar os polimorfismos de DNA nos genes leptina, β-lactoglobulina e fator de transcri??o pituit?rio espec?fico, em tr?s grupos gen?ticos de vacas leiteiras Holand?s x Guzer? e verificar a rela??o entre seus gen?tipos com a composi??o e qualidade do leite de vacas leiteiras. As amostras foram coletadas em agosto de 2009, sendo 113 amostras de sangue de vacas mesti?as em lacta??o e 58 amostras de leite. Para a an?lise do polimorfismo de DNA foram coletadas amostras de sangue, analisadas posteriormente no Laborat?rio de Gen?tica do Instituto de Zootecnia do Estado de S?o Paulo. As amostras individuais de leite foram coletadas segundo os padr?es estabelecidos pelo laborat?rio do Programa de Gerenciamento de Rebanhos Leiteiros do Nordeste (PROGENE), da Universidade Federal Rural de Pernambuco (UFRPE) para as an?lises de composi??o e qualidade do leite. A caracteriza??o dos gen?tipos foi realizada atrav?s da t?cnica de PCR-RFLP, em que foram utilizados primers espec?ficos para cada gene estudado e enzimas de restri??o Kpn2I, HaeIII e HinfI, promotoras de cortes nos genes leptina, β- lactoglobulina e PIT1, respectivamente. A freq??ncia genot?pica estimada da leptina foi CC 0,112 , TT 0,225 e CT 0,661, da β-lactoglobulina foi AA 0,136, BB 0,323 e AB 0,539 e PIT1 ++ 0,655, -- 0,311 e +- 0,032. Os resultados mostram que a popula??o se encontra em desequil?brio de Hardy-Weinberg para a leptina, β-lactoglobulina e PIT1 devido ao excesso de heterozigotos presentes na popula??o, entretanto, como estes genes est?o associados ? produ??o de leite, considera-se que os animais t?m potencial gen?tico para a produ??o leiteira nas condi??es do semi?rido brasileiro. Atrav?s da caracteriza??o do rebanho estudado n?o foram encontradas implica??es referentes ao polimorfismo da leptina, β lactoglobulina e PIT1 na composi??o e qualidade do leite de vacas nos grupos gen?ticos 1/2, 3/4 e 7/8 Holand?s x Guzer?
Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17175 |
Date | 29 August 2011 |
Creators | Campos, Miguel ?ngello da Silva Fernandes |
Contributors | CPF:05195601836, http://lattes.cnpq.br/2481533325379100, Morais, D?bora Andr?a Evangelista Fa?anha, CPF:50615912320, http://lattes.cnpq.br/7335358058619043, Lara, Maria Aparecida Cassiano, CPF:02502387809, http://lattes.cnpq.br/6030871198962363, Rangel, Adriano Henrique do Nascimento, CPF:29183375449, http://lattes.cnpq.br/9757343999118047, Guilhermino, Magda Maria |
Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Produ??o Animal, UFRN, BR, Sistemas de Produ??o Sustent?veis no Semi-?rido; Caracteriza??o, conserva??o e melhoramento gen?tico |
Source Sets | IBICT Brazilian ETDs |
Language | Portuguese |
Detected Language | English |
Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
Format | application/pdf |
Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
Rights | info:eu-repo/semantics/openAccess |
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