The rapid divergence of the ecdysone receptor is a synapomorphy for Mecopterida that clarifies the Strepsiptera problem
Article first published online: 31 MAY 2006
Insect Molecular Biology
Volume 15, Issue 3, pages 351–362, June 2006
How to Cite
Bonneton, F., Brunet, F. G., Kathirithamby, J. and Laudet, V. (2006), The rapid divergence of the ecdysone receptor is a synapomorphy for Mecopterida that clarifies the Strepsiptera problem. Insect Molecular Biology, 15: 351–362. doi: 10.1111/j.1365-2583.2006.00654.x
- Issue published online: 31 MAY 2006
- Article first published online: 31 MAY 2006
- doi: 10.1111/j.1365-2583.2006.00654.x; Received 12 October 2005; accepted after revision 23 February 2006.
- ecdysone receptor;
In arthropods, the regulation by ecdysteroids is mediated by the heterodimer between the ecdysone receptor (ECR; NR1H1) and ultraspiracle (USP/RXR; NR2B4) nuclear receptors. Both ECR and USP/RXR ligand-binding domains experienced a strong acceleration of evolutionary rate in Diptera and Lepidoptera, which belong to the superorder Mecopterida. We performed a phylogenetic analysis of 28 ECR and 30 USP/RXR protein sequences from 36 arthropod species, including representatives from Trichoptera, Mecoptera and Siphonaptera. Our data show that the acceleration of ECR and USP/RXR was a unique event in the ancestor of Mecopterida. Our analysis shows further that Strepsiptera ECR and USP/RXR sequences are unambiguously placed outside of the Mecopterida clade. Protein alignments reveal that eight of 11 synapomorphies support an affinity between Strepsiptera and Coleoptera sequences. The affiliation of Strepsiptera to Diptera should therefore be rejected.