The monophyly of Diplura and its phylogenetic relationship with other hexapods are important for understanding the phylogeny of Hexapoda. The complete 18SrRNA gene and partial 28SrRNA gene (D3-D5 region) from 2 dipluran species (Campodeidae and Japygidae), 2 proturan species, 3 collembolan species, and 1 locust species were sequenced. Combining related se-quences in GenBank, phylogenetic trees of Hexapoda were constructed by MP method using a crustacean Artemia salina as an outgroup. The results indicated that: (i) the integrated data of 18SrDNA and 28SrDNA could provide better phylogenetic information, which well supported the monophyly of Diplura; (ii) Diplura had a close phylogenetic relationship to Protura with high boot-strap support.
The phylogenetic position of the subfamily Coelotinae, which belongs to Amaurobiidae currently but Agelenidae formerly, has remained controversial. The sequences of 28S and 18S rDNA fragments were obtained from six species of spiders representing Ageleninae, Amaurobiinae, Coelotinae and Clubionidae. Neighbor-joining (NJ), maximum parsimony (MP), maximum-likelihood (ML) and Bayesian (BI) analyses generated identical tree topologies. All trees from the 28S rDNA data derived from neighbor-joining, maximum parsimony, maximum-likelihood and Bayesian analyses support the Coelotinae as the sister group of the Ageleninae, and strongly support the Coelotinae + Ageleninae are the sister group of the Amaurobiinae. The topology in the trees inferred from 18S data is similar to those of 28S rDNA but with lower boostrap support. The results indicate that Coelotinae is probably a subfamily of the family Agelenidae. In addition, the close relationship between Asiacoelotes and Draconarius of the subfamily Coelotinae, Agelena and Alloagelena of the subfamily Ageleninae is strongly supported by the results of analyses of the 28S rDNA sequences. This indicates that the sequence could be used as a molecular marker in the study of phylogenetic relationships among the genera of spiders.
