Phylogenetic analysis. Phylogenetic analysis of gcHIF1α and gcHIF4α against selected bHLH-PAS proteins from different animals. Phylogeny was performed on bHLH-PAS sequences by maximum parsimony (PROTPARS) using the PHYLIP package version 3.57 c . The bootstrap support (SEQBOOT program, PHYLIP package) for each branch (1000 replications) is shown. The standing of the abbreviations and the GenBank/EMBL/Swissprot accession number of the bHLH-PAS-A/B sequences used are provided in additional file 1.