Cloning and Characterization of hoxY Gene from Arthrospira and Spirulina and Its Application in Phylogenetic Study

The partial hoxY gene was cloned and characterized from 2 cyanobacterial genera,including 5 Arthrospira strains and 1 Spirulina strain.The gene encodes the small subunit of nickel-iron hydrogenase with the same length of 479 bp in two genera.The GC content ranges from 46.0% to 46.6% in Arthrospira and is 43.5% in Spirulina The similarities of nucleotide sequences among the 5 strains in Arthrospira(93.7%～100%) are higher than those between Arthrospira and Spirulina(69.5%～72.2%).The alignment of deduced amino acid sequence also indicates that S.subsalsa FACHB351 is phylogenetically distinct from the Arthrospira strains.The phylogenetic tree was constructed by comparing with the corresponding sequences of other 6 cyanobacterial strains.All the 5 strains of Arthrospira form a monophyletic clade,which is highly supported by the bootstrap values,while the Spirulina stain is in another clade.