Phylogenetic relationships of the New World monkeys (Primates, platyrrhini) based on nuclear G6PD DNA sequences

In order to test hypotheses about the phylogenetic relationships among living genera of New World monkeys, 1.3 kb of DNA sequence information was collected for two introns of the glucose-6-phosphate dehydrogenase (G6PD) locus, encoded on the X chromosome, for 24 species of New World monkeys. These data were analyzed using a maximum parsimony algorithm. The strict consensus of the three most-parsimonious gene trees that result shows support for the following clades: a pitheciine clade including Callicebus within which Chiropotes and Cacajao are sister taxa, an Alouatta-atelin clade within which Brachyteles is the sister taxon of Lagothrix and which is sister to another clade containing the callitrichines, and a callitrichine/Aotus/Cebus/Saimiri clade. Within the callitrichines, Callimico is the sister taxon of Callithrix. Cebus and Saimiri form a clade. These results are broadly consistent with previously published DNA sequence analyses of platyrrhine phylogeny and provide additional support for groupings provisionally proposed in those earlier studies. Nevertheless, questions remain as to the relative phylogenetic placement of Leontopithecus and Saguinus, the branching order within the Aotus/Cebus/Saimiri/callitrichine clade, and the placement of the pitheciine clade relative to the atelines and the callitrichines.