Data from: Hemocyanin gene family evolution in spiders (Araneae), with implications for phylogenetic relationships and divergence times in the infraorder Mygalomorphae

Hemocyanins are multimeric copper-containing hemolymph proteins involved
in oxygen binding and transport in all major arthropod lineages. Most
arachnids have seven primary subunits (encoded by paralogous genes a–g),
which combine to form a 24-mer (4 × 6) quaternary structure. Within some
spider lineages, however, hemocyanin evolution has been a dynamic process
with extensive paralog duplication and loss. We have obtained hemocyanin
gene sequences from numerous representatives of the spider infraorders
Mygalomorphae and Araneomorphae in order to infer the evolution of the
hemocyanin gene family and estimate spider relationships using these
conserved loci. Our hemocyanin gene tree is largely consistent with the
previous hypotheses of paralog relationships based on immunological
studies, but reveals some discrepancies in which paralog types have been
lost or duplicated in specific spider lineages. Analyses of concatenated
hemocyanin sequences resolved deep nodes in the spider phylogeny and
recovered a number of clades that are supported by other molecular
studies, particularly for mygalomorph taxa. The concatenated data set is
also used to estimate dates of higher-level spider divergences and
suggests that the diversification of extant mygalomorphs preceded that of
extant araneomorphs. Spiders are diverse in behavior and respiratory
morphology, and our results are beneficial for the comparative analyses of
spider respiration. Lastly, the conserved hemocyanin sequences allow for
the inference of spider relationships and ancient divergence dates.