Location: Corn Insects and Crop Genetics ResearchTitle: Effects of Wolbachia on mitochondrial DNA variation in populations of Athetis lepigone (Lepidoptera: Noctuidae) in China
|CHEN, FANG - Chinese Academy Of Agricultural Sciences|
|HE, KANG-LAI - Chinese Academy Of Agricultural Sciences|
|BAI, SHUXIONG - Chinese Academy Of Agricultural Sciences|
|ZHANG, TIANTAO - Chinese Academy Of Agricultural Sciences|
|WANG, ZHENYING - Chinese Academy Of Agricultural Sciences|
Submitted to: Mitochondrial DNA, Part A
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/31/2016
Publication Date: 8/23/2016
Citation: Chen, F., Coates, B.S., He, K., Bai, S., Zhang, T., Wang, Z. 2016. Effects of Wolbachia on mitochondrial DNA variation in populations of Athetis lepigone (Lepidoptera: Noctuidae) in China. Mitochondrial DNA, Part A. doi: 10.1080/24701394.2016.1197216.
Interpretive Summary: Bacteria that live within the cells of some insects can influence the reproductive success within an insect population by creating mating incompatibility between infected and unifected individuals. These resulting mating barriers also can effectively reduce gene flow within insect populations, and would violate a central assumption of current insect resistance management (IRM) strategies used to prevent or delay the onset of resistance to transgenic corn hybrids that express Bacillus thruringiensis (Bt) toxins. Chinese populations of a seedling corn pest insect, Athetis lepigone, were shown to have a Wolbachia bacterial infection rate of approximately 11 percent. DNA markers detected genetic variation among Athetis lepigone, but no significant genetic differences were present between Wolbachia infected and uninfected individuals. These results suggest that Wolbachia infections may not significantly reduce gene flow among Athetis lepigone, such that IRM strategies may be appropriate for delaying resistance to Bt toxins when transgenic corn hybrids are eventually commercialized in China. These results will be of interest to university, biotech company, and international stakeholders concerned with preserving the durability of Bt transgenic crops.
Technical Abstract: Wolbachia are endosymbiotic bacteria that infect arthropods and incompatibility among strains can affect gene flow within host insect populations, that can result in significant host mitochondrial DNA (MtD) variation. The effects of Wolbachia infection on mtDNA variation was studied in Athetis lepigone across 12 geographical populations sampled from North China. Mitochondrial COI gene and Wolbachia wsp gene were both obtained from 423 individuals, including 46 Wolbachia infected and 377 uninfected individuals. Average A. lepigone infection rate was 11 percent (range: 0 to 26 percent), and wsp sequence variation defined three distinct Wolbachia strains; Lep1, wLep2, and wLep3, respectively. A haploid network showed no relationship between A. lepigone mtDNA haplotype and Wolbachia infection. Furthermore, haplotype variation mainly exists within populations, although the proportion of variation is higher within uninfected compared to infected individuals. The lack of correlation between A. lepigone haplotype and Wolbachia strain, suggests symbiont infection may not affect mating compatibility or gene flow within host populations in China.