Skip to main content
Dryad logo

Data from: New ways to acquire resistance – Imperfect convergence in insect adaptations to a potent plant toxin

Citation

Dobler, Susanne et al. (2019), Data from: New ways to acquire resistance – Imperfect convergence in insect adaptations to a potent plant toxin, Dryad, Dataset, https://doi.org/10.5061/dryad.96224rg

Abstract

Evolution of insensitivity to the toxic effects of cardiac glycosides has become a model in the study of convergent evolution, as five taxonomic orders of insects use the same few similar amino acid substitutions in the otherwise highly conserved Na,K-ATPase α. We here show that insensitivity in pyrgomorphid grasshoppers evolved along a slightly divergent path. As in other lineages, duplication of the Na,K-ATPase α gene paved the way for subfunctionalization: one copy maintains the ancestral, sensitive state while the other copy is resistant. Nonetheless, in contrast to all other investigated insects, the grasshoppers’ resistant copy shows length variation by two amino acids in the first extracellular loop, the main part of the cardiac glycoside binding pocket. RT-qPCR analyses confirmed this copy is predominantly expressed in tissues exposed to the toxins, while the ancestral copy predominates in the nervous tissue. Functional tests with genetically engineered Drosophila Na,K-ATPases bearing the first extracellular loop of the pyrgomorphid genes showed the derived form to be highly resistant, while the ancestral state is sensitive. Thus, we report convergence in gene duplication and in the gene targets for toxin insensitivity, however the means to the phenotypic end have been novel in pyrgomorphid grasshoppers.

Usage Notes