Smells like teen spirit-Moth antenna pheromone receptors
Greetings, this is Trevor coming live from Ann Arbor in a basement…
We have one week left in the internship and things are finally starting to come together. Last time I made a post, I was without a doubt on the struggle bus in terms of getting data worthy of a poster, let alone a journal article. Since that point I have learned a hell of a lot of what not to do while recording data. First, always make sure everything is plugged in, second, make sure your specimen is alive, and last always make sure your equipment is hooked up everywhere it should be. You may think I’m weird for this, but I think my moths are pretty cute. A couple weeks ago I was having a really hard time getting clear recording from the BYB Spikerbox due to so much activity happening in the antennae, and as a result we switched to the SpikerShield to get an electroantennogram recordings. Electroantennogram recordings are low frequency, are the preferred way to record antennae stimulus and look like this:
Before I started testing the sex pheromone bombykol on the moths, I characterized how the male moths responded when introduced to their female counterparts, and it is best described as a circling motion in a zigzag path towards the female. It happens almost every time a female is brought within a couple feet of a male, but is not present when stimulated with just any odorant, like lemon oil or peppermint.
The male seems significantly less enthused about the lemon than about the female-I wonder why?
Once I had that complete I began trials with bombykol using a new delivery system that went through many revisions. At first we were using a valve system to deliver odors via an air stream, but we observed a change in airflow when opening valves, which meant we couldn’t be sure if the neuronal responses we got were from the change in airflow or the added odorant. To fix this problem, we inserted syringes into the piping with some T-junctions on the way to the moth, thus keeping a constant air stream.
Now I needed a way to consistently empty the syringes, so for that I added a linear actuator and a wood based housing to hold the actuator and syringes. The housing, entitled “Mr. Orange” due to its bright orange paint job and my love for Reservoir Dogs, has three ports for three syringes, to serve as an air control, other odorant positive control, and pheromone syringes all in one recording. Along the way, thanks to our fearless leader Greg I had to edit the housing from two to three syringe ports just minutes after completing the project…
Before “Mr. Orange” was built I was able to successfully record a bombykol stimulus on the last day of my second batch of moths. Displayed below is Bombykol compared to a negative control, aka clean air. Remember they only live 5-10 to days, and have to be ordered, so my time working with them is precious! I am currently awaiting new moths so that I can do my final trials which will involve mulberry leaves, which their caterpillars live on and eat, as a positive control for both male and female moths. This will allow me to show that both males and females react similarly to one stimulus (and ensure the prep is working), but also that they have evolved such that males are much more sensitive to bombykol than females.
Last but not least, the interns all presented last week at MID-SURE, a poster session on Michigan State University’s campus in East Lansing, and I have included my poster below for anyone curious.