Basking in the Glow

Dyson Professor Andrew Wier studies the symbiosis of the Hawaiian Bobtail Squid and bioluminescent bacteria in the hope of shedding some light on human bacterial infections.

“They pretty much eat better than I do,” jokes Andrew Wier, PhD, assistant professor of Biology and Health Sciences. He’s talking about the Hawaiian Bobtail Squid; purple golf ball-sized, shrimp-eating invertebrates that glow in the dark and sometimes call Pace their home.

The tiny tropical predators piqued the interest of Wier, who collects his own specimens, because of the unique symbiotic relationship they share with the bioluminescent bacteria Vibrio fischeri. This mutualistic interaction between the squid and the bacteria, how the bacteria thrive without causing suffering or infection in the squid, is just one of the aspects that Wier is studying.

“What makes them interesting to me as a research scientist is that when they are born—when they hatch from their clutch of eggs—they are free of bacteria, but very quickly—like humans—acquire bacteria from their environment,” he says.

Soon after hatching, the nocturnal squid collect the microbes they need to survive. The bacteria, which Wier says act as a  cloaking device, inhabit the squids’ light organ and get the nutrients they need from the squid, in return, the bacteria illuminate to match the amount of moonlight hitting the top of the squids’ mantel. This essentially erases the shadow of the squid, allowing it to hunt its prey in stealth mode. Each dawn, before burying itself in the sand, the squid ejects up to 95% of the V. fischeri from its light organ.

The bioluminescent bacteria, Vibrio fischeri, inside of the squid light organ. Transmission electron micrograph.

“I am interested in the dialogue—the molecular interaction—between the host squid and the symbiotic bacteria,” says Wier. “The bacteria is related to Vibrio cholera which cause diseases in humans. We see this in countries like Haiti that can’t get clean water.” For Wier, understanding the symbiotic relationship between the squid and V. fischeri could be the key to gaining a better understanding of human bacterial diseases. Wier plans to collaborate with parasitologist and Director of the Haskins Laboratories Nigel Yarlett, PhD, to aid in his research.

Also helping with Wier’s research are the biology students who chose to do in-lab research as part of their Capstone course. The students help to conduct research that faculty is working on and help to fund grants, bring in money, and publish first-rate scientific papers.

“The students are doing real research here,” says Wier. “They’re interested in going to medical school, going into academia and even physical therapy, and they find that the value of working in a lab, getting to know their professors, and getting this real world experience puts them head and shoulders above the crowd.”