Maestro Of The Venomous Violin

Portland Professor In National Spotlight For Her Work On The Brown Recluse Spider

By Kathy F. Mahdoubi

Walk in Greta Binford's footsteps for a moment. Imagine that you're in Peru, trekking through the Amazonian rainforest, engulfed by curtains of lush, dense vegetation. Troupes of monkeys are swinging in the canopy above you as anteaters amble down the barely beaten path ahead. Your long journey ends at what appears to be just a rock. You push it over with both hands, and as it rolls backward, an entire world opens up to you as a million little things burst into action every which way. If you were Binford, you'd be looking for one critter in particular: the brown recluse spider, otherwise known as the fiddleback.

Binford, an assistant professor of biology at Lewis & Clark College, Portland, Ore., is considered an expert on the fiddleback. The brown recluse spider has taken on this peculiarly musical pseudonym because of a very distinct marking on the dorsal side of its upper body, or cephalothorax, which looks just like an upside-down violin. It's hard to miss this black little fiddle on the back of one of these very poisonous spiders, especially when Binford is holding it out for you in the palm of her latex-gloved hand, as she did for a recent Discovery Channel special about her work.

It's hard to believe that anyone would have such a devout passion for spiders. They invoke the heebie-jeebies in the average person and utter terror in the average arachnophobe.

Since her first foray into the Peruvian rainforest in 1988, when she observed the feeding behavior of social arachnids in the field, Binford has conducted a mountain of research on spider species diversity and the molecular biology of spider venom. The brown recluse, or Loxosceles recluse, is especially of interest to Binford because the venom of its genus contains a very dangerous toxin that isn't found anywhere else in the animal kingdom.

Her research has caught the attention of the National Science Foundation (NSF), and she's now been awarded the Foundation's Faculty Early Career Development (CAREER) Program award. The highly competitive prize is given to those promising young scientists who are deemed future leaders in their field and who successfully mentor their students through intensive and integrative research.

"The CAREER awards are one of the most prestigious awards that the National Science Foundation grants," says William Zamer, NSF program director. "We want to give these young individuals enough funding and support to move their careers along fairly quickly in the beginning stages."

Binford was awarded $643,877 for a five-year program of research called "Venom evolution in brown recluse spiders: a system of undergraduate training in integrative biology." In conversation, Binford explains the nature of her research with enthusiasm and obvious reverence for the animals she studies.

"It's an integrative project, meaning I do research that's both working with the animals themselves, with the live, whole animals and I'm also doing molecular biology focusing on the toxin," says Binford. "In the process of doing this I'm learning a lot about the biodiversity of the spider group, as well."

Her undergraduate students participate at every level of the research, including traveling all over the world to collect live specimens. It's the multi-disciplinary nature of her work and the intensive student involvement at Lewis & Clark that caught the attention of the NSF.

"Lewis & Clark is primarily an undergraduate institution and the NSF values research that takes place in those institutions," says Zamer. "We firmly believe that the integration of education research is the best way to educate the students about science and technology. It's all of these things combined that made this compelling research, and it warranted a funding recommendation."

The body of the brown recluse is typically less than three-fourths of an inch long and its natural habitat is North America, especially in the Midwest and the southern states. Relatives of the brown reculuse are native to other parts of southern North America, South America, Africa, and the Mediterranean region. The brown recluse loves to hide in attics, garages, and in old clothing. The underside of rocks or wood piles make perfect spider nesting grounds, which renders these spiders easy targets out in the field--and it's the field work that Binford loves the most.

"It's kind of like a big scavenger hunt. Underneath every rock is a Christmas package," says Binford.

Back at the lab, she and her students analyze the chemistry and genetic code that makes the recluse's particular "venom cocktail" possible. The toxic enzyme that she is hunting down is called Sphingomyelinase D, which has been known to cause some pretty horrendous tissue damage in the worst cases of brown recluse spider bites.

Binford knows every step of the physiological process that occurs after a recluse or one of its genus sinks its fangs into mammalian flesh, injecting an as yet unknown quantity of its venom into its victim. Apparently, the Sphingomyelinase enzyme attacks the essential cel membrane protein sphingomyelin, which causes the cell to rupture. This process begins an immune response and soon the body restricts blood flow to the bite site.

"Basically your body commits tissue suicide right at that little site," says Binford.

The result is called a dermonecrotic lesion, which essentially means that the surrounding tissue dies and becomes gangrenous. Eventually the dead flesh falls away, leaving a gaping wound that can take months to heal. In the most serious cases, a wound can grow up to 10 inches in diameter, causing such a cavernous hole that patients seek skin graphs to mask scar depth.

Despite these unsettling details, Bill Robertson, the medical director of the Seattle-based Washington Poison Center, says that these scenarios are not at all representative of the average brown-recluse bite. In fact, Robertson says that the average bite is about one to two centimeters in diameter and although the Sphingomyelinase enzyme is incredibly toxic, Robertson says that only 10 to 20 percent of those bitten will develop a necrotic lesion.

Northwesterners can relax even further, because the recluse isn't even indigenous to this region of the country. "We have the Hobo spider, which is sort of the second cousin twice removed," says Robertson.

Venomous biters in general are actually few and far between, says Robertson. In reality, only five to ten species of spiders have the mouth parts for people-chomping. That's more than a little ironic considering most peoples' intense fear of being bitten.

It's obvious where Robertson's sympathy lies: "The poor spiders . . . . Where did they get their terrible reputation?"

Death by brown recluse is rare. Again, in worst case scenarios, fiddleback venom can cause systemic symptoms, including rash, fever, chills, nausea, vomiting and rarely, renal failure, or coma, a lot of this has been found to be more psychosomatic than as a result of a bite, he says.

Like Robertson, Binford would have you know that brown recluse bites are very rare indeed, let alone deadly. "As their name suggests they're very shy. They're very mellow spiders and they're very reluctant to bite."

The only time that these gentle guys bite is if they are trapped and mashed up against skin, like inside clothing, for instance. Years in the field and day after day of working with these spiders and so far, neither she nor any of her colleagues or students has been bitten, but regardless of the spider's sweetness, the nasty effects of a fiddleback bite is still cause for concern.

Binford and her students study recluse venom by extracting it directly from the spider. This is done by subjecting spiders to a harmless draft of carbon dioxide, which puts them to sleep. In this unconscious state, the spiders can be held with delicate forceps as Binford cleans their fangs with a syringe of water and a little vacuum to prevent insect debris from contaminating the venom sample. She calls it "spider dentistry." Binford then steps on a foot pedal that delivers an electrical shock of about 12 volts, which "milks" the spider, forcing it to expel a small volume of its venom, which Binford then collects for analysis.

What Binford and her team want to know is when the toxin first arrived on the evolutionary scene and what species first used this unique toxin to immobilize their prey. The brown recluse's genus, which includes at least 100 different species of spiders, is said to be about 110 million years old. With comparative analysis, Binford hopes to study this toxin across spider species in the hope of improving diagnoses and bite treatment.

"We hope that we will be able to create diagnostics and treatment that will not just work on one species but will work across the entire breadth of species with this toxin and that includes some pretty unrelated animals," Binford says.

Before she began her current research with Lewis & Clark College, Binford completed her doctoral research at the Department of Ecology and Evolutionary Biology at the University of Arizona. While she was there, she worked with the Arizona Poison control Center, helping them to diagnose recluse bites, which are often misdiagnosed, and by identifying the chemistry of the venom itself.

As a renowned spider expert, Binford also served as a consultant for the feature film "Spider-man." Set designers wanted the movie's laboratory scene to be as close to an actual lab as possible. They corresponded closely with Binford over the course of film production, getting exact specifications for spider containment, equipment, and procedures. In the end, the meticulous setup of transparent terrariums and apparatus in the scene is pretty much a doppelganger for the containers and equipment in the Lewis & Clark lab.

Binford certainly seems to be scaling her way to spider-woman status, but none of that interests her as much as the science itself. She is perfectly content in the lab or in the field, playing the littlest violin, conducting the symphony of spiders.

Kathy F. Mahdoubi is a freelance writer and recently graduated from the editorial journalism program at the University of Washington, Seattle.

Image:

The brown recluse has a very distinct dorsal marking that resembles a violin and is seen here at its typical size, smaller than a quarter, although the recluse has been known to grow much larger. Photo: University of Nebraska Dept. of Entomology