As the end of the Brisbane portion of our trip quickly approaches, the final venom biology projects are coming to a close. All 24 of us are completing independent projects based off of our personal interests in venom effects, evolutionary history, and protein composition in venoms across numerous species. For my independent project, I have been running a series of bioassays using venom from the Red Tiger Assassin Bug and observing the effects of their crude venom on different model organisms in order to determine prey specificity. I have been working at the University of Queensland’s Institute for Molecular Biology with Dr. Andrew Walker, the leading expert in the world on Assassin Bug venom, and am incredibly fortunate to be surrounded by experts in the venom biology field.
I ran my first series of bioassays following the milking of the bugs from yesterday. I previously milked 27 bugs using electrostimulation and by doing so, I successfully collected 14.8 microliters of crude venom. Today, I diluted the venom with sterile water to a 1:4 mixture, and injected 1.74 microliters of the solution into each of my model organisms (crickets and blowflies). I ran a series of 5 controls for each species tested on, which consisted of injections with water at the same volume. Venom effect was measured by escape time of both species in comparison to their control escape times. While the crickets were slightly affected by the venom as shown by their elongated escape times, the flies died immediately after injection, illustrating that there is evidence of prey specificity that is somehow selected for in the venom of the bugs in order to affect certain species more than others.
Following my bioassays, I do not have much left to do in order to complete my project, however, my findings open the door for plenty of research to come about these unique bugs and their highly specialized venom. My studies not only motivate the question as to why there is prey specificity within the venom of these bugs, but how this has come to be, and what peptide cocktail has led to these miraculous properties? I encourage you all to read the literature surrounding assassin bug venom and fall in love just as I have with their unique molecular make-up!