Phylogenetic utility of the ribosomal internal transcribed spacer 2 in Strumigenys spp. (Hymenoptera: Formicidae)

Sequence variations and phylogenetic relationships of Strumigenys from different localities in Taiwan were inferred from sequences of the internal transcribed spacer 2 (ITS2) of nuclear ribosomal RNA genes. The ITS2 sequences of different species of Strumigenys vary in length from 659 to 953 bp, because there are many large repeated insertion-deletion fragments, and these short tandem repeat units form microsatellites. The average GC content of the ITS2 is 60.8%. Secondary structures from ITS2 sequences are similar and present several conserved structural motifs. Eleven species and three unnamed species were analyzed using both the maximum parsimony and maximum likelihood methods. Although diversity of the ITS2 sequence is high, these data can still be a potential tool for primary analysis of molecular phylogeny and biogeography of Strumigenys at the species level on islands around Taiwan.