Lymphoproliferative Disease Virus (LPDV) is a retrovirus that induces an acute, horizontally transmitted turkey disease that is often fatal (Gazit et al. 1979; Yaniv et al. 1979). LPDV represents a distinct group of avian retroviruses closely related to avian sarcoma-leukemia viruses (Chajut et al. 1992). The genomic structure of LPDV is 7.1 Kb in size including pro-LTRs of 118 and 257 nt. The internal region of this retrovirus displays a Primer Binding Site (PBS) complementary to a tRNATrp, Open Reading Frames (ORFs) for gag, pro, pol, and env genes characteristic of retroviruses, four small ORFs whose function is unclear, and a Polypurine Tract (PPT) adjacent to the 3´LTR (Gak et al. 1991; Sarid et al. 1994).
Figure not to scale. If present, long terminal repeats (LTRs) have been highlighted in blue. Amino acid motifs noted with lines indicate the conserved residues in each protein domain, abbreviations below mean:
||DU or DUT=dUTPase
||TAV or IBMP=transactivator/viroplasmin or inclusion body matrix protein
||PBS=primer binding site
||ATF=aphid transmission factor
||VAP=virion associated protein