Identification, Characterization, and In Vitro Culture of Highly Divergent Arenaviruses from Boa Constrictors and Annulated Tree Boas: Candidate Etiological Agents for Snake Inclusion Body Disease

Stenglein, Mark D.; Sanders, Chris; Kistler, Amy L.; Ruby, J. Graham; Franco, Jessica Y.; Reavill, Drury R.; Dunker, Freeland; DeRisi, Joseph L.

Genome analysis. Analysis of the recovered genome sequences revealed that they possess attributes characteristic of arenavirus genomes, including a bisegmented ambisense organization, with two opposite-sense open reading frames (ORFs) on each of two genome segments (Fig. 3A ) (20, 21) . Also, as is the case with other members of the family, on both segments the intergenic regions separating the ORFs were predicted to form hairpin structures, with predicted Gibbs free energy changes (⌬G) of between Ϫ50 and Ϫ91 kcal/mol at 30°C (22) . The inter-ORF sequences of the S and L segments of GGV and CASV share 38% and 42% pairwise nucleotide identity, respectively, in global alignments. Also consistent with arenavirus genome structure, the terminal 19 nucleotides (nt) at the 5= and 3= ends of the L segment are nearly reverse complements of each other and are similar to the 5=-and 3=-end sequences of the S segment (Fig. 3B ). The terminal sequences of these viruses are conserved at 13/19 residues with the terminal sequences of previously described arenaviruses (Fig. 3B ). The L and S segments of CASV measure 6,812 nt and 3,368 nt, respectively, while the L and S segments of GGV measure 6,922 nt and 3,482 nt, respectively.