It only took one parasitology course in Associate Professor of Biology Judith Humphries’ undergraduate years to hook her. Since then, her interest in all things parasite-related has grown into numerous research projects.
Her current research concerns a freshwater snail species local to Central and South America as well as Sub-Saharan Africa called Biomphalaria glabrata. The very existence of this snail is an integral part of the life cycle of the wormlike parasite species Schistosoma mansoni, acting as their primary host, leading them to come in contact with humans. Once the parasite enters the human body, it spreads its eggs to the liver, which causes a condition known as schistosomiasis, causing swelling to the abdomen or spleen, as well as liver and intestinal damage. The condition is especially dangerous to the human populations it typically effects due to widespread malnourishment plaguing the areas. However, Humphries believes if the snail is better understood, we can better find ways to combat the spread of the parasite and eventually eradicate the disease.
“If there’s something unique to the snail’s nervous system, we could target it and take [the] snail host out of the equation.” Humphries said. “If we manipulate [the] snail so it does not allow parasites to live in it, we can stop infections.”
To better understand Biomphalaria glabrata, Humphries spent the summer overseeing three different student projects, all of which are still ongoing. While the three were starkly different, they all studied the snail’s nervous system, which she believes is largely understudied and may hold answers to eliminating initial infection.
The first student project concerns a chemical called neuropeptide Y (known simply as NPY). Built off a previous student’s project that originally discovered the chemical in the brain, the current experiment takes things a step further; the student is dissecting a whole snail and working through its tissue to discover where else NPY might be found. Levels of NPY are much higher in snails that are infected by Schistosoma mansoni than those who are not, and NPY appears to play a role in symptoms of the infected hosts. The location of the tissue NPY is present in can also suggest what it might do. The student working on this project has reaffirmed the presence of NPY in the brain and has discovered it also exists in the mouth.
The second project turns our focus to the nervous systems of Biomphalaria glabrata embryos, since they look different than the nervous systems of their adult counterparts. The student intends to find when the restructuring from original to adult nervous system occurs and target possible susceptibilities to Schistosoma mansoni in it.
The final project has been analyzing mRNA expression in the “beaded bracelet”-looking adult brain of Biomphalaria glabrata. Since parasite activity has been known to change host behavior, the governing question of the experiment is: are there differences in the infected snails versus the healthy ones?
Since the projects are mostly capstones for the students, Humphries will be overseeing them to the end of the year. While she is unsure if any major discoveries will be made, she acknowledges that each experiment is a step towards eradicating schistosomaisis, no matter how small that step may be.