Phylogenetic Inference
The set consisting of type-I interferon amino acid sequences from human (Homo sapiens), domestic pig (Sus scrofa), duckbill platypus (Ornithorhynchus anatinus) and the amino acid sequences corresponding to the Chiropteran genes inferred in this paper was submitted to multiple sequence alignment by CLUSTALW 2.0.10 [36] and ProbCons 1.12 [37]. Maximum likelihood and minimum evolution phylogenies were inferred from each resulting multiple sequence alignment. Maximum likelihood phylogenies were inferred with proml found in the PHYLIP 3.68 package [38]. Minimum evolution phylogenies were inferred using fastme[39] based on the distance matrix calculated with protdist found in PHYLIP. In both cases, 1000 boot-strap replications were generated using seqboot and the consensus phylogeny was assembled with consense, both from the PHYLIP package. FigTree 1.2.1 http://tree.bio.ed.ac.uk/software/figtree/ was used for initial visualization and final production of figures of the resulting phylogenetic trees. Alignments of the bat DNA sequences and of all the amino acid sequences are available in additional files 4.