Monday, 11 August 2014

Flies to ciliates and back again: a postdoc story

I've been very fortunate in my short yet eventful career to have worked on some quite varied, but still connected, projects. As I said in my last post (which was a long time ago - sorry!), the golden thread running through my work has been an attempt to understand the influence environment, particularly stressful conditions, has on phenotypic traits. In doing so, I haven't really shown a lot of fidelity to the study organism I use.

Larson cartoon - always reminds me of herping fieldwork!
My honours project was conducted on skinks, a fairly numerous lizard group within Australia. At that stage of my studies, I was under the grand delusion that I would be a "herper" forever. When my then supervisor suggested I switch to fruit flies to follow my very keen interest in evolutionary processes, I almost laughed at her! I learned two important things from her that year; 1) a spider is never a valid excuse for missing a lizard, and 2) never say never.

One year later, I found myself 3000km from home starting a PhD on Drosophila. I admit I may have been lured into the project under the promise of working on dung beetles (seriously, dung beetles are awesome!), and yet I still spent 4 years alternately caring for, and then committing genocide on, 100's of 1000's of flies. My family and friends outside the lab could not honestly believe that I was paid to spend my weekends tending to countless populations and species of flies. On top of that, I was prone to using explicit fly terminology at seemingly inappropriate times (FYI, "pooting" and "sexing" flies is definitely not as exciting as it may sound). Some of my most important collaborations and scientific papers have come from this work so these little flies are nothing to sneeze at. Except, or course, if you develop an allergy to them, which does indeed happen along the way. I was fortunate not to become allergic to the flies themselves, but rather the food we used to maintain them.

Tetrahymena thermophila
(via Wikimedia Commons)
After moving half way across the country for my PhD, my first postdoc position saw me move half way around the world to the magical land of beer and chocolate - Belgium. Here, I left behind flies that saw me chained to my lab bench every 2nd day and began working on the even smaller, unicellular organism, . Again, if you'd told me during my undergrad that I would spend part of my career building play-gyms for single celled critters using bits of plastic tubing and microcentrifuge containers, I would have been just a little disbelieving. But wouldn't you know it, that is exactly what we did. In order to study dispersal propensity in these rather active single cell ciliates (with 'hairs' all over the them that act as propellors through their watery environment), we joined two containers with plastic tubing, filled them up with medium, loaded the cells into one tube and measured the number of cells that moved across to the other. If you don't believe me, see the Pennekamp et al. paper recently out in Evolution. I was just getting in to making similar play-gyms for spider mites (at least slightly larger than T. thermophila) when my second postdoc opportunity came up.

For the last almost 2 years I have been back working on flies, only this time on Ceratitis species, a pest fruit fly of the South African and international fruit and veg market. It has a kind of nice symmetry to be back working on flies, although I did skip a group along the way. Hopefully the lizards will make a comeback at a some stage. I suppose the moral of the story is to follow what interests you and don't get hung up on the "where" and "what". Life is much more interesting that way! More on my current work in the next update.

Sunday, 20 April 2014

Inaugural post

Hi everyone, and welcome to my first blog post! My name is Kate and I am an Australian postdoctoral researcher currently based in Stellenbosch, South Africa. I've created this blog to post about my crazy research shenanigans and any other interesting tid bits associated with my scientific life. As the sole proprietor of this blog, it will be my humble opinion that decides what is interesting and/or crazy and I make no apologies for that. Hopefully you will agree with me at least to some extent.

As the blog name suggests, my research revolves around evolutionary physiology, in particular, thermal physiology in insects. In a nutshell, I'm interested in understanding how insects' thermal tolerance relates to their current distributions and how this translates to their ability to withstand and adapt to changing environments. In traditional genetics studies, phenotypic plasticity, or the ability of the same genotype to produce a different phenotype depending on the environment, was something that was generally considered a nuisance. However, from an evolutionary perspective, it is mighty interesting! This ability to buffer short-term changes in environment may assist with adaptation by allowing individuals to survive and reproduce through less favourable conditions and by potentially providing variation for selection to act. Alternatively, it can hinder adaptation by shielding less fit genotypes from what would otherwise be detrimental conditions and allowing their offspring to persist in the next generation. Catch 22!

The eyespot pattern of Bicyclus anynana is a good example of developmental plasticity. The temperature and humidity cues received during development cause the adult butterflies to express one of two colour morphs. The larger eyespot size during the wet season is believed to be a deterrent against predators during the lush wet season. Image of seasonal polymorphism in wing eyespot size in Bicyclus anynana and expression patterns in 3 associated genes from Oliver et al. (2013) doi:10.1371/journal.pone.0065830 2013  © Oliver et al.

Phenotypic plasticity is a term that encompasses different types of responses operating over long or short time scales and can be fixed or reversible. What they share in common are being phenotypic changes that occur within the lifetime of a single individual, the mechanisms underlying which we know very little about. In physiological traits, and thermal tolerance traits in particular, they tend to be short-term and reversible, meaning the environment an organism is exposed to now can greatly influence the trait you want to study in a few minutes or a couple of days from now. So, that hiccup in your incubator that made your bugs a little chilly yesterday? That's going to give you some grief when you come to test cold tolerance tomorrow! You're welcome :)

So, there's a very brief background to what I do. I'm also interested in dispersal dynamics and the genes and environmental conditions that influence an individual's willingness and ability to depart plus issues surrounding the transient lifestyle of the postdoctoral researcher, being a female in science and a foreigner abroad etc. Stay tuned for whatever little nuggets I decide to send along!