Here’s our summary: In aquatic environments, where the vast majority of animals live in darkness, key relationships are often formed and maintained by chemical communication (including smell and taste). Parasites with an aquatic life phase rely on an exquisite sense of chemosensation to detect host biomolecules (kairomones), allowing them to locate and infect their host. Our study identifies the first kairomone released by the freshwater gastropod snail Biomphalaria glabrata, an intermediate host for the helminth blood fluke parasite Schistosoma mansoni. This is a key aspect of the S. mansoni life-cycle that ultimately leads to human infection, causing the disease schistosomiasis (or bilharzia), which is considered the most devastating human helminth infection in terms of global morbidity and mortality. The kairomone we identify is a peptide that does not appear to share any similarity with any other known animal peptide. This information will be helpful as we explore methods to interrupt parasite infection, and therefore break the cycle of infection that causes a major human disease.
Citation: Wang T, Wyeth RC, Liang D, Bose U, Ni G, McManus DP, et al. (2019) A Biomphalaria glabrata peptide that stimulates significant behaviour modifications in aquatic free-living Schistosoma mansoni miracidia. PLoS Negl Trop Dis 13(1): e0006948. https://doi.org/10.1371/journal.pntd.0006948
Wyeth, R.C. 2019. Olfactory navigation in aquatic gastropods. Journal of Experimental Biology 222(Suppl 1): jeb185843. doi:10.1242/jeb.185843.
This was an invited review and the final outcome of last year’s Journal of Experimental Biology symposium and now part of a special issue from JEB: Linking brain and behaviour in animal navigation. The review covers what is known about the behaviour and neurobiology of aquatic slug and snail navigation – finding prey and mates and avoiding predators. Along side that in the special issue are other reviews of navigation research in insects, fish, bats, turtles, humans and more. Check out the journal’s summary here: Navigation: from animal behaviour to guiding principles (with Tritonia front and center yet again!). A big thank you to Ken Lukowiak, Dennis Willows and Marc Weissburg who were instrumental in sending RCW down the path that led here.
It was was great to have a packed audience for this event on Fri Jan 18, 2019 sponsored by the Office of the Associate Vice President Research and Graduate Studies. Our thanks to Dr. Richard Isnor.
Abstract: In a recent article, “Patterns vs. Causes and Surveys vs. Experiments: Teaching Scientific Thinking,”The American Biology Teacher80 (2018), 203-23, Prof. R. Wyeth (Biology, StFX) and Prof. M.Wonham(Biology, Quest Univ.,BamfieldMarine Sciences Centre) argue that the hypothetical-deductive method is a tractable view of the modern scientific method as it provides the basic structure for students to conceptualize experimentalinquiry. By contrast, Prof. Byrne argues that the basic structure of experimental inquiry is inductive, rather than deductive, does not always require an hypothesis to be tested, and is not hypothetical in any interesting sense of this term. In this discussion,Professors Wyeth and Byrne will present their views on the place of the hypothetical-deductive method in modern experimental science. They will also consider the recent history of the hypothetical-deductive method, particularly its connection to Karl Popper,as well as its application to teaching the scientific method to university students. Given its subject matter, this talk should be of interest to all faculty and upper-level students in the experimental sciences, whether natural, social or medical.
And the outcome? Well, we both learned more about each other’s perspectives and we agree on many aspects of how science works and how the formal description of the hypothetical-deductive method (as laid out by Popper) doesn’t fit science very well at all. But there are points of contention, particularly with regard to exploratory science – where is the boundary with non scientific observation and do exploratory surveys have implicit hypotheses or not?
Alex wrapped up all his revisions yesterday, and submitted his thesis today.
Expression Patterns of Neural-Specific Genes in the Pond Snail, Lymnaea stagnalis
Two and a bit years of hard work culminated in 5 total chapters – 3 of which are destined for publication. He used bioinformatics, quantitative PCR and in-situ hybridization to find patterns of gene expression, focusing on neurotransmitter-related genes in Lymnaea. Congratulations Alex on a fantastic achievement. Next up for him: some more work wrapping up those publications, and then hopefully off to start a PhD.
Areej Alansari has gotten caught between the governments of Saudi Arabia and Canada. She has to head home very soon. Fortunately, she has just enough data collected for her MSc on snail navigation behaviour, so she can now focus on writing up the thesis from a distance. We are all looking to give her as much support as possible so she can finish up her degree after investing so much into it over the last couple years. It was a fun send-off party (for biologists).
This summer, Kero continued our work testing the snail navigation behaviour towards food sources. His experiment focused how the animals performed in the dark but with water flow. That meant he had to first construct a cover in order to block any light from reaching the flow tank. Then 54 trials across 3 different treatments, comparing responses to tasty food (to a snail) to two control conditions. Then analysis of the video data began: transforming all the trials into videograms and tracking the different snails throughout out the trials.