Rapid Evolution of the Mitochondrial Genome in Chalcidoid Wasps (Hymenoptera: Chalcidoidea) Driven by Parasitic Lifestyles

Jin-Hua Xiao,Robert W Murphy,Da-Wei Huang,Jing-Guo Jia,Trine Bilde

doi:10.1371/journal.pone.0026645

Abstract

Among the Chalcidoids, hymenopteran parasitic wasps that have diversified lifestyles, a partial mitochondrial genome has been reported only from Nasonia. This genome had many unusual features, especially a dramatic reorganization and a high rate of evolution. Comparisons based on more mitochondrial genomic data from the same superfamily were required to reveal weather these unusual features are peculiar to Nasonia or not. In the present study, we sequenced the nearly complete mitochondrial genomes from the species Philotrypesis. pilosa and Philotrypesis sp., both of which were associated with Ficus hispida. The acquired data included all of the protein-coding genes, rRNAs, and most of the tRNAs, and in P. pilosa the control region. High levels of nucleotide divergence separated the two species. A comparison of all available hymenopteran mitochondrial genomes (including a submitted partial genome from Ceratosolen solmsi) revealed that the Chalcidoids had dramatic mitochondrial gene rearrangments, involved not only the tRNAs, but also several protein-coding genes. The AT-rich control region was translocated and inverted in Philotrypesis. The mitochondrial genomes also exhibited rapid rates of evolution involving elevated nonsynonymous mutations.

Highlights

In most animals, the mitochondrial genome is maternally inherited, generally nonrecombining with other mitochondrial lineages, and comprised of 13 protein-coding genes, 2 rRNAs and 22 tRNAs
The sequenced fragments contained proteincoding genes, tRNAs, and 2 rRNAs (12s incomplete) (Figure 1 and Table 1)
We report the successful sequencing of the almost complete mitochondrial genomes from two species of Philotrypesis that shelter in the same figs

Summary

Introduction

The mitochondrial genome is maternally inherited, generally nonrecombining with other mitochondrial lineages, and comprised of 13 protein-coding genes, 2 rRNAs and 22 tRNAs. The mtDNA of the honeybee, Apis mellifera, has been available since 1993 [2], today few other complete hymenopteran genomes are known [3]. This situation may be due to two characteristics: the mitochondrial genome is extremely ATrich rendering amplification and sequencing difficult and it has unusually high rates of substitution and frequent gene arrangements that confound primer design and amplification [4,5]. For the Chalcidoidea, only a partial mitochondrial genome is known from Nasonia, and it has an unusually high accelerated rate of evolution and several unique gene rearrangements [6]

Methods

Results

Conclusion