Research highlight: North Carolina Institute for Marine Sciences

Research Highlight: North Carolina Institute for Marine Sciences

In fall 2013, 3rd year graduate student Samuel Slocum traveled to the University of North Carolina Institute for Marine Sciences to collect marine samples for his thesis research. Read about his adventures here.  

Collection trip at the North Carolina Institute for Marine Sciences

Near the end of October in 2013, Dr. David Sherman invited me to a conference call with Niels Lindquist, a marine biologist at the University of North Carolina Institute for Marine Sciences.  I was already familiar with his name from some of the earliest papers on the discovery of the bryostatins, which are small molecules found on the free-swimming larvae of the “moss animal” Bugula neritina.  These molecules serve to make fish really really want to avoid eating the larvae. Additionally, the bryostatins have a whole host of interesting biological activities: anti-cancer (they were first discovered when they doubled the life span of lab mice with lymphocytic leukemia), neuroprotective, immunomodulatory, and even some antiviral implications have been made. As it turns out, bryostatins are actually produced by a symbiotic bacteria living inside a sinus of the larvae.  Unfortunately, this bacterium has thus far refused to grow outside of its host, so in order to study the biosynthesis of bryostatins you either need a bunch of larvae or an even larger bunch of adults.  Which brings me back to the conference call. 

Niels said that the Bugula were looking like they are nearing their reproductive season (which happens for about two weeks twice a year), and that they should be producing larvae soon. Because my thesis project revolves around the biochemistry of the enzymes that assemble bryostatins rather than the biology of the animal, I didn’t realize at that point that I would be doing fieldwork in a matter of days.  In any case, I am the only one in the lab working on B. neritina­-related science, and by the end of the conversation it was decided that I would fly down to Morehead City, NC and rustle up some moss animals and their larvae.

I was excited to be expanding my research into an area I had only ever considered briefly, and also to be getting out of the rapidly cooling Ann Arbor and into the kinder climate of the Carolina coastline.  I spent the next three days putting myself through a crash course in genomic DNA isolation and sample preservation techniques as well as assembling a small box of reagents and materials that I mailed to my future self in Morehead City.  Before I knew it, Niels was picking me up from the airport in New Bern, NC, about a 45-minute drive from the Institute for Marine Sciences.  The drive was extremely informative about a great variety of topics: the biology of Bugula, the larger-scale marine biology and ecology that Niels was now studying, the politics of the North Carolina coastline, and the absurd cost of replacing the little computer screen in the dashboard of his Prius. 

Unfortunately, the weather in Morehead City was about as bad as Ann Arbor when we arrived at the two-story brick buildings that housed the Institute for Marine Sciences.  My collections were highly dependent upon sunshine (more on that later), so I hoped that the horizontal misting of seawater would subside quickly.  Niels gave me a tour of the lab spaces, and I learned that marine biologists mean it much more literally when they say, “wet lab”.  In his wet lab space there were several water tables: essentially a shallow tank of water with a drain at one end and a hose bringing in unfiltered seawater at the other.  Niels had been extremely helpful and had actually gone on a dive a few days prior to gather a good amount of Bugula, and this first haul was waiting patiently in one of the water tables.  

Not much happened on the first day.  It was too late in the day to try to collect larvae, and the shipment from my past self hadn’t arrived yet.  I did meet a fellow Bugula enthusiast and dedicated biologist Jonathan Linneman, who had been traveling up and down the southeastern United States to study geographic variations in B. neritina populations.  Interestingly, Jonathan’s PhD advisor (Nicole Lopanik) held a postdoctoral position under my current PhD advisor some years before starting her lab at Georgia State University.  It’s a small world for those studying B. neritina.  We discussed our projects and the lifestyle of B. neritina at length, and had an exciting problem solving session when we realized we didn’t have any sample loading dye for agarose gels.

The second day brought more of the same weather.  Overcast, light rain, and only a few tantalizing seconds of sunshine at a time.  In order to gather larvae, a good amount of the adult is placed into a large mason jar full of seawater, which is then placed into the sun.  I’m unsure of the exact mechanism, but the light triggers the adults to release their sand grain sized larvae, which then swim up to the surface of the jar and gather along the rim where they can be (relatively) easily collected.  Without the sunlight, the pickings were fairly slim.  After three hours of babysitting mason jars full of moss (to avoid stressing the animals currently trapped without a steady flow of seawater), I called it a day. 

Jonathan and I then decided to hedge our bets by gathering some more Bugula.  If the weather wasn’t going to coax more larvae from the adults, then we could at least gather larvae from more adults.  We headed east out of Morehead City and crossed the bridge into Beaufort.  I had no idea what the collection would entail, but it turns out that Bugula neritina grows within arms reach on the underside of most floating docks around the city.  We had some interesting questions from the folks on the docks, and some perplexed looks as we explained that these were actually animals that produced cancer-fighting drugs.  We had great luck with finding reproductive adults, and by sunset we had more than doubled the amount of adult animal in Niels’ water tables. 

The sun still refused to push through the clouds on the third day.  Yields of larvae were much higher thanks to the huge amounts of animal in the jars, but I was still disappointed with the total at the end of the day.  I was consoled by a beautiful sunset over the complex strings of tubing and outdoor tank systems around the Institute for Marine Sciences.  Thankfully, the clear skies that delivered the sunset continued for the next two days.  The first fifteen minutes of collection on those days gave more larvae than the first two days combined.  At the end of my last day I gathered a backup batch of adult B. neritina to be used in case the larvae didn’t work out back home. 

By the time I was packing up to leave, fall had arrived in Morehead City.  The overnight temperatures were much cooler than the first muggy nights, and I didn’t feel as bad leaving the coastline to go back to the certain cold in eastern Michigan.  My B. neritina adults and larvae were frozen, sealed, and dropped off at the UPS store, and after another 45 minute conversation with Niels and a few hours on planes, I was back in the LSI waiting anxiously for another package from myself.