Keywords: دستگاه Polypurine; AIDS; acquired immune deficiency syndrome; ALV; avian leukosis virus; AMV; avian myeloblastosis virus; APOBEC; apolipoprotein B mRNA-editing enzyme-catalytic polypeptide-like; ASLV; avian sarcoma leukosis virus; AZT; 3â² -azido-3â² -deoxythymidine; BIV;