DETECTION OF GENETIC DIVERSITY AMONG BOVINE LEUKEMIA VIRUS POPULATION BY SINGLE-STRAND CONFORMATIONAL POLYMORPHISM ANALYSIS

Single-strand conformational polymorphism (SSCP) was applied to analyse the occurence of BLV proviral variants in cattle naturally infected with BLV. A 444-bp fragment of BLV env gene was amplified and subjected to SSCP analysis. Twenty one DNA samples with different migration patterns, representing eight migration profiles, were found in a total of 72 analysed samples from BLV-infected cattle. SSCP analysis of 48 samples of the same restriction type (Belgian subgroup) revealed 34 and 14 samples with identical and different migration patterns, respectively. Nucleotide sequencing of two samples with distinct SSCP patterns confirmed sequence differences. SSCP analysis provides a facile and discriminatory tool for the differentiation of BLV variants, including those previously indistinguishable by RFLP.