By two dimensional electrophoresis using acrylamide disc and slab gels, hemocyanin hexamers of four araneid spiders
Argiope amoena, A. bruennichii, Araneus ventricosus, Nephila clavata, and a pisaurid spider
Dolomedes sulfureus were separated completely into individual subunits. Direct protein sequencing of hemocyanin monomer subunits gave the N-terminal sequences for the first 10-25 amino acid residues, except for subunits with blocked amino terminals. From the sequence comparison between the araneid spider's hemocyanin subunits, it is supposed that the araneid spiders share the subunits with similar N-terminal sequences derived from a common ancestral sequence and that duplications of the ancestral sequence occurred in the lineages of
A.
amoena and
N. clavata or in the common ancestor immediately before the divergence of these two spiders and then in the lineage of
N. clavata. On the contrary, the pisaurid spider has hemocyanin subunits with unique N-terminal sequences which are not found in any hemocyanin until now.
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