Five months have passed since I last focused on the Public Engagement series with Maria Duque, at Sanger Institute. The focus: parasites and Neglected Tropic Diseases (NTD’s).
I meet a new scientist (#5 out of 6) who introduces me (and you) to yet another malicious actor/parasite and its destruction/disease.
When I first connect with Dr. Sarah Buddenborg, it’s November and she is at the Wellcome Sanger Institute, in the UK. We finally meet via zoom, on a Monday afternoon, this last May. She’s in transition mode, having returned to the US, to begin a new position a week from the day we speak.
Upon introductions, I learn she’d received a PhD in Biology, at the University of New Mexico. I tell her I received my MFA at New Mexico State University. We both agree the NM desert is great landscape.
Side note: During this pandemic, when the lab Sarah works in, shuts down, she works tracking Covid-19 cases. Curious, I ask a few questions, and then I force myself to stay focused on the blood fluke, Schistosoma mansoni. (We’ll talk Covid sequencing another time!).
Sarah works on the parasite, S mansoni.
“It’s truly an incredible worm, she says, with separate male and female adult worms that fit together like a hot dog inside a hot dog bun! …I’ve worked with S. mansoni for over 12 years now, only recently switching from looking at the snail host stages to the sexual development and sexual differentiation of males and females.”
I confess, from the various parasites on the list, I choose this one because its intermediate host is a snail. I imagine a coiled worm and a spiraled snail could make for engaging, line compositions.
Schistosoma mansoni (shisto = split and soma = body).
I spend an afternoon sketching these ↑ adult parasitic worms only to get a sense of their fascinating architecture.
-The male (with suckers, oral and ventral) has a gynaecophoric canal (gunaiko = female and phoros = bearing). This ventral groove is where the female fits. (See her ↑ in there!)
-They mate for life. (Though rumor has it the female can wander to a new mate.)
-They are big enough to see with the naked eye.
-They live inside the portal vein of their human host. (Eek! Is this right?!)
-They lay about 300 eggs a day. (Which land in host’s liver…ugh!)
-They travel against gravity, in this case, against the flow of blood.
-These worms wreak some havoc.
I set up the snail and detail in some of its anatomy.
Keep in mind, I choose this parasite because I want to draw a snail. As I begin to understand the poor creature is the intermediate host, I don’t want to add eggs or larval stages to the composition. I want to leave this ↑ snail the whole and complete focal point. #safe #sound
Here is how this stage of the worm’s life cycle plays out:
Eggs are excreted into freshwater ↓ via urine or feces, from an infected human.
Question: Can eggs be seen with the naked eye?
Eggs hatch releasing free-swimming, ciliated (note hair-like ↑ edge) miracidia (from the Greek meaning youth) into surrounding water. The miracidia burrow into (Sarah uses the phrase “takes over“) tissue of a freshwater snail, specifically Biomphalaria glabrata.
Questions: Does the snail suffer? How long is the snail able to survive such a hijacking of its body?
Inside of the snail, miracidia lose their cilia, developing into mother sporocysts through asexual reproduction, eventually emerging are daughter sporocysts, further morphing into the fork tailed cercaria phase. #Shapeshifter
Sarah’s photo background influences my composition.
Sarah shows me this one ↑ photo as she emphasizing tens of thousands of cercaria are released by the snail and will eventually borrow (penetrate) into a human host.
Interesting note: temperature, light and chemistry play important roles in how this bug navigates.
Sarah explains how the parasite enters the definitive host (human), and how worms maneuver through that system, where they end up, and how the whole cycle gets repeated. She also talks genomics and sequencing and assembling sex chromosomes, showing me a karyotype and quickly running through a few details about the female and male.
I ask Sarah what draws her to this kind of work. She notes the travel and the field work in the small villages where transmission is highest and how this has allowed her to witness the suffering. She knows the impact of her work.
Thank you Sarah!
And welcome back to the US.
TBC…
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Monica Aissa Martinez 