Q&A: Alex Fogarty ’13 Studies the Chemistry Behind Lobster Molting

 

Alex Fogarty ’13

 

Alex Fogarty ’13 received a Howard Hughes Medical grant this summer to do research with Josiah Little Professor of Natural Sciences Patsy Dickinson and Chemistry Professor Beth Stemmler on the American lobster.

Her research project, “Chemical measures to assess the Molting Cycle in the American Lobster: Understanding the role of ecdysteroids using an LC-MS approach,” should help further crustacean research. Fogarty, a Romance languages major and chemistry minor who is planning on attending medical school, spent the summer preparing and analyzing lobster blood samples and learning that science often offers an unexpected “element of surprise.”

Bowdoin Daily Sun: What exactly is an American lobster?

Alexandra Fogarty ’13: The American lobster, Homarus americanus, is the species of lobster most common to the eastern coastline, extending from Labrador to New Jersey. Due to its iconic status in Maine, fishermen often refer it to as the Maine lobster. On the Bowdoin campus, however, it is the guest of honor at the annual lobster bake, and is therefore very popular for dinner!

BDS: Can you describe the question you were trying to answer this summer?

AF: The lobster will molt frequently throughout its lifetime, and our research starts with this in mind. This “molting” corresponds to the animal shedding its external carapace, revealing a newly synthesized one. This new shell will eventually harden and replace the old one altogether. While complicated, this process allows the lobster to grow larger throughout its lifetime so it is very important to lobster biology. In the lab, we are trying to identify the chemical that triggers the molting cycle in the lobster by analyzing lobster blood using an LC-MS (liquid-chromatography, mass-spectrometry) instrument.

BDS: What were your days like?

AF: Initially, many hours were set aside for calibrating the LC-MS instrument. Using purified samples of the chemical of interest, we studied how the instrument reacts to that molecule. Later on, days working on this project were spent collecting samples of lobster hemolymph (lobster blood) and preparing them for analysis by adding various chemicals and subjecting it to purification steps. I also had the chance to go visit the local lobsterman near Harpswell and see him and his crew in action. We came back that day with about 25 lobsters!

BDS: What do you feel you gained from your work this summer, both personally and intellectually?

AF: This experience certainly has given me a greater appreciation for the intricate process that is scientific research. While this project only made use of a small number of techniques, each one had to be learned very carefully in order to have some successful analysis. The element of surprise also was something that required an adjustment of mind-set: while it may seem that an experiment is bound to succeed on paper, in practice, it can actually result in total chaos for no apparent reason. I certainly learned to appreciate how science is not as black and white as in the textbook.

BDS: Has your project inspired you to continue in this area? Such as launching another research project or an honors/independent project?

AF: I will be continuing this project as an independent study this academic year. I hope we will be able to optimize our experiments to the point that you could pick up a lobster, sample its blood, and we could tell you what stage of molting its presently in. This would have many uses in other areas of crustacean research. Since molting is such an important process in the lobster, it is thought to involve many complex biological pathways. When the process is underway, the same molecules may have different physiological effects on these pathways. This is because the molt cycle is causing different combinations of hormones and other chemicals to be released, which will have secondary interactions elsewhere. Many researchers are attempting to explain such extraordinary secondary interactions by evoking the molting cycle. However, this can’t be done conclusively without a way to chemically pinpoint the stage of the molting cycle in which the lobster of interest lies, which is part of why we were working towards establishing the chemical definition of the molting cycle this summer.

BDS: Does your research shed light at all on the current soft-shelled lobster phenomenon that’s in the news?

AF: Lately the buzz on lobsters has to do with fishermen trying to market the soft-shelled lobster to make them just as appealing to consumers as the typical hard-shelled lobster. This is because the soft-shelled animals are allegedly making up a larger percentage of the catch, but most people are still used to purchasing the hard-shelled animals. For the most part, these reports date back to the very beginning of the lobstering season. During a visit to Harpswell this summer, a lobsterman told me that the animals had molted unusually early this season due to the very warm ocean temperatures. As we all know, last winter was very mild and this apparently led to an earlier first molt, which would explain the higher number of soft-shelled individuals early in the season.

In my experience working this summer (later in the lobstering season), I had the opposite problem: none of the lobsters we could find were soft (or “softer”) shelled! Presumably, this is because their exoskeletons would have just hardened completely after this first molt of the season, making it unlikely that they would be molting again until late summer or fall. This made it difficult to perform our analysis given that these lobsters had such low levels of the molting chemical we were interested in. In the fall, we hope to encounter some lobsters that are once again closer to molting. This will really make our experiments much more straightforward since more of our chemical of interest will be circulating in the lobster blood.

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