Diseases and sex: The cocktail maintaining immune gene variation
The great variation of a specific form of immune genes makes organ transplants so complicated. On the other hand, we need such a great variability in order to resist infectious diseases. This is why it also plays a major role in the selection of sexual partners. Up until now, the mechanisms for maintaining this standing genetic variation have remained an evolutionary puzzle. In a study of sticklebacks, researchers from the Max Planck Institute for Evolutionary Biology in Plön, together with colleagues from the Helmholtz Center for Marine Research in Kiel, have now shown that reoccurring infectious diseases determine which individuals produce a particularly large number of offspring in a population, and which immune genes increase in frequency in the next host generation. Infections are thus the drivers for this variability.