Na,K-ATPase NewsCoevolutionary escalation led to differentially adapted paralogs of an insect's Na,K-ATPase optimizing resistance to host plant toxins

1 June 2023, by Marlena Winter

The milkweed bug, Oncopeltus fasciatus, has evolved intricate adaptations to the toxic cardenolides present in its host plants. Amongst others its Na,K-ATPase (NKA) has evolved strong resistance against these toxins. This resistance is due to the possession of several gene copies of the NKA subunits that carry different substitutions. We expressed nine combinations of alpha and beta-subunits of the NKAs in cell culture and tested the resulting proteins for their resistance against two different cardenolides: the routinely used ouabain, and calotropin, a cardenolide abundant in O. fasciatus' host plants. Our analyses show that over the course of evolution the bugs' NKAs became ever more resistant against cardenolides in general. In addition the youngest proteins evolved a higher resistance against calotropin compared to ouabain. This speaks for a stepwise escalation of adaptations in the coevolution of the plants and their herbivores.

The publication in the journal Molecular Ecology can be found here #mce_temp_url#