EN
The aim of the foregoing experiment was the determination and comparison of the nucleotide and amino acid sequences of the vIL-8 gene of Polish MDV strains. Twenty three samples isolated from field cases of Marek’s disease virus during the years 1976 2005 were used in the experiment. The presence of the gene was confirmed in all examined samples. No changes in the vIL8 sequence were stated, except of the three following strains, where singular nucleotide changes were observed: 16/05 (25 C→T; 243 C→T; 281 G→A), PZ /95 (25 C→T; 184 A→G; 243 C→T; 281G→A), 5/01 (168 C→T; 220 T→C), 11/02 (464 T→A), 23/99 (665 T→A), 14/05 (551 T→A, deletion of 680 base). These changes were reflected in amino acid sequences of the three isolates, as point and random changes: 16/05, PZ/95 (4 S→L, 31 G→D), and 14/05 (88 F→L). It appears that these changes did not show any pattern displaying association with the degree of the pathogenicity of the virus, and that the gene encoding vIL8 in most cases did not change within 30 years.