Full house

Michael Hogan sent me the picture below from the lab last week. The image is from one of our two lab spaces, and I think it is nicely representative of what I love about my lab group. In this picture, we have one postdoc (Carl), two PhD students (Micaiah and Mike), and three undergraduates (Gabrielle, Laura, and Elizabeth). Carl is using a computational approach for characterizing effects of mutations on bacteriophage capsids. Micaiah is murdering Drosophila with centipede venom. Gabrielle, Laura, and Elizabeth are feeding our collection of venom invertebrates. I am going to pretend that Mike has some RNA extractions or RNA-seq library preps set up out of frame…


Venom extraction

Michael Hogan put together the video below of a new(ish) venom extraction protocol he developed. We are always working to improve the live-animal techniques we employ to reduce the stress and discomfort to the animals and the risk to the handlers. Good technique, but I am not so sure about the music…

Mark is out of here

Well, Mark Margres successfully defended his Ph.D. thesis entitled “The Genetics of Adaptation of Island Rattlesnakes” on November 8, 2016. He then braved driving across the country in the middle of winter to Pullman, WA, where he joined Dr. Andrew Storfer’s lab at Washington State University. Mike Hogan kindly produced a video of Mark’s defense talk (below).

West Texas – field venom extraction

Mike Hogan put together a short video of how we process venomous snakes in the field. In the video, venom extraction is being performed by Mark Margres, with Micaiah Ward and Alyssa Bigelow assisting. Both animals being processed are Crotalus ornatus. The goal is to get venom and blood samples from each individual while minimizing handling and stress on the animal. The blood samples are used for genetics, and the venom samples are analyzed proteomically to compare venom compositions between species or population (such as we did here).

West Texas 2016

Members of the Rokyta Lab and Dr. Lisle Gibbs’ lab traveled out to west Texas at the end of June after the Evolution Conference in Austin for several days of fieldwork. We did extremely well with venomous species. We saw numerous western diamondback rattlesnakes (Crotalus atrox), prairie rattlesnakes (Crotalus viridis), Mojave rattlesnakes (Crotalus scutulatus), black-tail rattlesnakes (Crotalus ornatus), and a single rock rattlesnake (Crotalus lepidus).  We’ll be posting more pictures and videos from this trip soon.

From left to right: William Booker (Lemmon lab), Mark Margres, Micaiah Ward, Alyssa Bigelow, and Mike Hogan. 

Mike Hogan got some good video of a western diamondback rattlesnake:

Centipede venom extraction

We started trying to work with centipede venoms in 2014, but we struggled for months to perfect the process of venom extraction. We were used to snakes, with their huge venom yields and long-established procedures for extracting venom. And snakes, of course, have no legs, which actually makes them fairly easy to move around and restrain. Suddenly, we had legs everywhere. Fast, grippy legs. Venom yields were often so low that the liquid would evaporate faster than we could convince ourselves that there was actually something there.

Fortunately, Dr. Eivind Undheim was incredibly generous with his advice on how to extract venom from centipedes, and we were able to develop a procedure that works consistently. The animals are first anesthetized by exposure to CO2 for about two minutes, which keeps them under for three to five minutes. We then restrain them using velcro strips while we apply electrostimulation to the bases of the forcipules. The forcipules are the modified first pair of legs that house the venom glands. We use a commercially available TENS unit to apply low voltage/high frequency elctrostimulation to induce muscle contraction and expel the venom. We use a small spatula to catch the venom and to prevent its mixing with saliva. The video below shows the process after the animal has been anesthetized.