Physiological changes associated with evolutionary and ecological processes such as diversification, range expansion or speciation are still incompletely understood, especially for non-model species. Here IBE researchers study differences in protein expression in response to temperature in a western Mediterranean diving beetle species complex.

This paper rounds-up Ignacio Ribera's group excursion into proteomics, by looking at changes in protein expression patterns through the speciation process. In summary, they found changes in metabolic-related proteins expressed at high temperatures when a north-African species colonised the Iberian peninsula in the late Pleistocene, going into a climate with lower seasonality and lower maximum temperatures. These were changes likely to have occurred in allopatry, and were not associated to changes in body or genital morphology.

Once in SE Iberia there was a speciation event, likely to have occurred in close geographical proximity, resulting in two morphologically distinct species. This process was associated to changes in the expression of stress proteins (as e.g. chaperons) at low temperatures, and indeed the newly formed species is able to stand lower temperatures, and since the last interglacial expanded to occupy most of western Europe and north Africa.

Reference article: A Hidalgo-Galiana, M Monge, DG Biron, F Canals, I Ribera and A Cieslak (2015). Protein expression parallels thermal tolerance and ecologic changes in the diversification of a diving beetle species complex. Heredity