Epigenetic regulation of immunity: methylation profiling in the mealworm beetle, Tenebrio molitor

Immune responses incur a large energy cost for organisms. Hence, environmental conditions such as nutritional status may change how an organism’s immune response genes are expressed, and these changes can be inherited by offspring. At the centre of this is the concept of epigenetics: the process by which environmental factors alter an organism’s DNA expression. These changes can be heritable, and so it is widely hypothesized that epigenetics is the key mechanism driving the co-evolution of hosts and parasites. This study used T. molitor to investigate the regulatory role of a particular type of environmentally induced epigenetic change, methylation, on immune response levels. Beetles were subjected to different starvation treatments before being presented with a bacterial immune challenge. Immunoassays and methylation sensitive AFLP demonstrated that methylation patterns in this species are subject to change following a period of starvation, and that starvation downregulates phenoloxidase activity levels.