ALVE-JFevB integration site within a GGERV20 element. ALVE-JFevB is intact with gag, pol, and env ORF with detectable subunits. GGERV20 is in the negative orientation and contains putative gag and pol ORFs. pol is truncated at the 3′ end, but the 4 core catalytic components remain unaffected. Abbreviations: ALVE, avian leukosis virus subgroup E CA, capsid; INT, integrase; LTR, long terminal repeat; MA, matrix; NC, nucleocapsid; ORF, open reading frame; PR, protease; RH, RNaseH; RT, reverse transcriptase; SU, surface; TM, transmembrane.