Mark Lammers

- personal website -

Summary of my Research Interests

I am interested in virtually all insects and their interspecific interactions with a particular focus on the evolutionary selective pressures that shaped their life-history and/or interaction. Moreover, I expect that understanding the interactions between species provides clues to question why some many species of insects co-exist on our planet. I started recording and collecting these insects in nature about 14 years ago and it is still one of my main hobbies. These studies made me a strong proponent of natural history: I believe that much more is to be discovered outside of our laboratories, in the wild.

Parasitoids are an excellent model system for studying interspecific interactions due to the massive number of species and the close co-evolutionary history with their hosts. These interactions can lead to the loss of traits in a species when one partner compensates the needs of the other ecological partner. This concept on compensated trait loss attained increasing intention over the last years, but the molecular mechanisms underlying this phenomenon are hitherto unknown. In my PhD I aim to elucidate these mechanisms and thereby find causal factors driving the evolutionary loss of traits.

Many independent lineages of parasitoids have lost their ability to convert and store dietary sugar in the form lipids as adults, therefore depending entirely on the fat supplies of their larval hosts. However, most parasitoids are also able to feed on nectar and other sugar-containing solutions for their daily maintenance, which allows them to spend their host’s lipids on egg production. The ample supply of host lipids relaxed the need for lipogenesis, which led to a total loss of lipogenesis in some species. So far, the molecular mechanism underlying this case of trait loss remains unknown.

Several well-described cases of trait loss could be traced back to the degradation of a single gene. For example, the gene GULO encoding a key enzyme in the synthesis of vitamin C, is degenerated in humans, which explains our inability to produce this essential vitamin. Another potential mechanism which would explain trait loss, is the (permanent) silencing of a key gene. This could be achieved by regulatory changes, DNA-methylation, et cetera.

In my PhD project, I attempt to elucidate the molecular mechanisms behind the evolutionary loss of lipogenesis in parasitoids. Currently I am investigating all the above-mentioned mechanisms. This requires a healthy mix of wet-lab molecular analyses, bio-informatics and experiments with live insects.