Inside the Tangled Bank of Arthropods

 

I am a molecular evolutionary biologist, primarily interested in the interactions of arthropods with symbiotic bacteria, plants, and pesticides. My research focuses on trait and genome evolution that is driven by ecological interactions and toxins.
As model systems, I mainly use plant feeding spider mites of three different genera; Tetranychus, Bryobia, and Brevipalpus, and their bacterial endosymbionts; Wolbachia, Rickettsia, Spiroplasma, and Cardinium. These arthropod herbivores display great variation in their host plant range with some species being strictly monophagous, whereas others are highly polyphagous.

 

 

 

It has been a brilliant week!

 

Our comparative genomics manuscript on symbiotic Ca. Tisiphia was published in Nature Communications, work that was spearheaded by Helen and Stefanos (click here for more!). In addition, our study that identifies and dissects intraspecific host modulation of Wolbachia-mediated CI was also published in Evolution Letters. Here, we uncover that spider mite males and females control different features of CI and confirm that the evolution of reproductive parasitism is contingent on host genetics (click here for more!). Next week, our work with Jens Zarka and Thomas Parmentier on intersexuality in Porcellio isopods will also be published!

 

Lennert Beele also defended his excellent thesis on Dobzhansky-Muller incompatibilities and Wolbachia-induced CI in Tetranychus urticae and Tetranychus cinnabarinus.

 

Tomorrow, I’m going to Montpellier for a week of meetings and pilot experiments (and hopefully some wine and cheese too!).

 

Overdue for an update!


The last PhD chapter of Masoumeh is now published by PLOS Genetics! Here, we uncovered the complex genetic architecture underlying resistance to pyflubumide (a complex II inhibitor) by combining transcriptomic analyses and high-resolution genetic mapping. Two QTLs centered on cytochrome P450s that were overexpressed in resistant populations. We further corroborated the involvement of one of these P450s, CYP392A16, in resistance by in vitro functional expression and metabolism studies. Our genomic analyses also strongly indicated that gene amplification of CPR could enhance cytochrome P450-mediated detoxification, suggesting a novel molecular mechanism of toxicokinetic resistance.

In our research to study genetic conflict, we are currently tracking the spread of Wolbachia in replicated experimental populations that differ in their ability to suppress reproductive parasitism. We are at day 60 (approx. fifth-sixth generation) and already extracted DNA from 300 female mites. We took a risk, but are getting great results!  

Summer is over and I sampled my last T. urticae field population yesterday in the Beisbroek forest near Brugge.

I am very proud to announce that Masoumeh’s PhD thesis has been approved by the Doctoral Committee and that her doctoral defence ceremony will take place on November 17th at 15:00. Unfortunately, due to travel restrictions, the ceremony will mostly be virtual without in-person interactions. But everyone will be able to follow the procedures via a livestream!

Some weeks ago, I finished Martin Brasier’s truly excellent book Darwin's Lost World where he very clearly outlines the recent scientific discoveries and theories on the Cambrian explosion. The author also recounts his own wonderful personal research history and takes you to various remote locations across the globe where his key findings were made.