The long repeat region is dispensable for fowl adenovirus replication in vitro

Two regions containing tandemly repeated sequences are present in the fowl adenovirus 9 (FAdV-9) genome. The longer repeat region (TR-2) is composed o f 13 contiguous 135-bp-long direct repeats, the function of which is unknow n. An infectious FAdV-9 genomic clone, constructed by homologous recombinat ion in Escherichia coli, was used for engineering of recombinant viruses. T he enhanced green fluorescence protein (EGFP) coding sequence was cloned in both rightward and leftward orientations so as to replace TR-2. Replicatio n-competent recombinant FAdVs were recovered, demonstrating that TR-2 was d ispensable for FAdV-9 propagation in vitro. The expression of EGFP in infec ted cells was demonstrated by fluorescence microscopy, immunoprecipitation, and RT-PCR, (C) 2001 Academic Press.