ABSTRACT: Bovine spongiform encephalopathy (BSE) is a transmissible progressive neurodegenerative disease characterized by the accumulation of a pathological isoform (PrpSC) of the cellular prion protein (PrpC) in the brain of cattle. Two insertion/deletion polymorphisms in the PRNP gene (23bp in the promoter and 12bp in intron 1) have been associated with resistance or susceptibility to the disease. The aim of this study was to analyze the distribution of these polymorphisms in 214 healthy bovines belonging to four different breed groups (Aberdeen Angus, Aberdeen Angus x Hereford, Holstein Friesian and Uruguayan Creole cattle). DNA samples were amplified by end-point PCR. A high frequency of the alleles and haplotype associated with susceptibility to BSE (del12 and del23, and del12-del23, respectively) were found in the Aberdeen Angus, Aberdeen Angus x Hereford and Holstein Friesian animals. At the same time, the Uruguayan Creole cattle presented a higher frequency of the alleles and haplotype associated with resistance to BSE (ins12 and ins23, and ins12-ins23, respectively). These data could indicate a greater genetic resistance of the Uruguayan Creole cattle to BSE compared to other analyzed breeds, reinforcing its value as a zoogenetic resource. ABSTRACT (BSE PrpSC (PrpSC PrpC (PrpC insertiondeletion insertion deletion 23bp bp 1 21 . cattle) endpoint end point PCR del12 del (del1 del23 del12del23, del12del23 deldel del12-del23 respectively animals time ins12 ins (ins1 ins23 ins12ins23, ins12ins23 insins ins12-ins23 respectively. breeds resource 2 del1 (del del2 del12del2 del12-del2 ins1 (ins ins2 ins12ins2 ins12-ins2 del12del del12-del ins12ins ins12-ins
RESUMO: A encefalopatia espongiforme bovina (EEB) é uma doença neurodegenerativa progressiva transmissível dos bovinos, caracterizada pelo acúmulo no cérebro de uma isoforma patológica (PrpSC) da proteína priônica celular (PrpC). Dois polimorfismos de inserção/deleção no gene PRNP (23bp no promotor e 12bp no íntron 1) foram associados à resistência ou suscetibilidade à doença. O objetivo deste trabalho foi analisar a distribuição desses polimorfismos em 214 bovinos sadios, pertencentes a quatro diferentes grupos raciais (Aberdeen Angus, Aberdeen Angus x Hereford, Holstein Friesian e Crioulo Uruguaio). As amostras de DNA foram amplificadas por PCR de tempo final. Uma alta frequência dos alelos e haplótipos associados à suscetibilidade à BSE (del12 e del23 e del12-del23, respectivamente) foram encontrados nos animais Aberdeen Angus, Aberdeen Angus x Hereford e Holstein Friesian, enquanto o gado Crioulo Uruguaio apresentou maior frequência dos alelos e haplótipos associados à resistência à BSE (ins12 e ins23 e ins12-ins23, respectivamente). Esses dados podem indicar uma maior resistência genética do gado Crioulo Uruguaio à BSE em comparação com as outras raças analisadas, reforçando seu valor como recurso zoogenético. RESUMO EEB (EEB PrpSC (PrpSC PrpC. PrpC . (PrpC) inserçãodeleção inserção deleção 23bp bp 1 21 sadios Uruguaio. Uruguaio) final del12 del (del1 del2 del12del23, del12del23 deldel del23, del12-del23 respectivamente ins12 ins (ins1 ins2 ins12ins23, ins12ins23 insins ins23, ins12-ins23 respectivamente. analisadas zoogenético (PrpC 2 del1 (del del12del2 del12-del2 ins1 (ins ins12ins2 ins12-ins2 del12del del12-del ins12ins ins12-ins