Also, selection is not the only mechanism that can result in inter-population variance. Genetic drift is a stochastic mechanism that can change the frequency in alleles within a population www.selleckchem.com/products/Belinostat.html regardless of the influence of ecological gradients. Although in this case, the type of micro-evolutionary process responsible is not directly demonstrated, the processes were found to cluster bi-directionally depending on climate of population origin. This indicates an extremely low chance that observations were the result of random genetic drift, as the same protein expression trends appear to be lost or gained in the opposing direction at each geographical origin. Non-random genetic causes, such as direct exchange of genetic material between two or more of the populations studied here can also be ruled out.

For example, New Zealand and Chile have national policies in place that restrict the importation of bees yet these two populations showed a high degree of similarity. The cases are less clear-cut between the Californian and Hawaiian populations or between those from Saskatchewan, nevertheless each of these breeders maintains that there has been no intentional genetic exchange among the populations in question. Likewise, even populations who share a traceable common ancestor but who had several years to adapt to their current environment did not show any greater similarity than those sharing a climatic region, e.g., the Ontario and Saskatchewan Russian lines. In the data presented here, pairs of populations that shared the most similar latitudes tended to have the most similar protein expression profiles.

Through the analysis of isozymes of malate dehydrogenase, latitudinal clines present across several continents have been identified in honey bees [9]. Natural and introduced Drosophila populations also exhibit similar allelic clines shown by isozyme polymorphisms of alcohol dehydrogenase (ADH) and glycerol-3-phosphate dehydrogenase (GPDH); the present study demonstrates selective pressure on these same enzymes whose expression patterns seem to correlate with latitude (reviewed by [35]). Although these markers provide an unbiased association with which to identify local adaptation, they also indicate that metabolism is often a selective target of local adaptation. Temperature influences the biosynthesis, stability and activity of proteins with functional adaptation of homologous proteins to their operating environment common [36].

While proteomics does not allow us to determine the presence of alloenzymes between populations, Carfilzomib bi-directional segregation of pathways for metabolism and protein folding with latitude is consistent with the presence of distinct ecotypes for the warmer Californian/Hawaiian and colder Saskatchewan and Ontario populations.