Professor Cheryl Hayashi, Iolani Class of 1985, and a 2007 winner of a MacArthur Genius Grant, spoke during Meeting Period in Seto Hall on Tuesday to an audience that hung on her every word, wrapped in the web of her enthusiasm, knowledge and passion for, of all things, spiders and the amazing silk they produce.
The MacArthur Foundation description of Dr. Hayashi and her work is printed below.
On Tuesday, she went far beyond such a dry summary of her life and work. Upon leaving 'Iolani in 1985, "I was going to be a flight attendant or a lawyer," remembered Hayashi.
That changed at Yale when, as a first year student, she enrolled in a course on evolutionary biology. That class set her feet upon the vocational path of biologist, but it was a part-time job feeding spiders in a research lab that introduced her to the arachnids that would become her life's work.
The job led to field station work in Panama, rising at 3:30 in the jungle to study the habits of tropical spiders.
Hayashi continued her graduate work, earning a Yale Ph.D jointly with the American Museum of Natural History in New York. She did post doc study at the University of Wyoming in Laramie, a town, according to her, that had a smaller--and much less diverse--population than her block in New York. There she learned more about spiders and also about being an ethnic minority in a majority culture, an issue most Asian students growing up in Hawaii rarely consider.
Her tenure at UC Riverside began in 2001, and she is now an Associate Professor there.
Having followed this "meandering path," Hayashi threw herself into the unexplored field of spider silk marveling at the "marvelous diversity" of this substance that starts out as "goo" in the spider's abdomen and becomes at least seven different kinds of fiber as it is extruded from nozzles or spigots called spinnerets.
Spiders use the silk for safety lines, egg sacks, protective retreats, and prey catchers. They produce a different silk for each purpose--"task specific silk."
While marvelling at the pure genius of spider architecture and evolution, Hayashi also studies the possible applications of the mechanical and genetic information she is gaining.
Silk is stronger and tougher than Kevlar, and that raises potential for uses in body armor. Also, unlike most fibers, it contracts when wet, so it could be used for field bandages and aerodynamic body suits.
While such uses may be in the future, scientists such as Hayashi, are searching for ways to produce the silk in a standard, efficient way. Since farming predatory spiders has its obvious drawbacks, Hayashi has used the genetic information gleaned from spider silk to devise a cloning method that allows her to grow silk in tomato and tobacco plants.
"For every question I answer, I find ten more," says Hayashi, noting that our scientific ignorance far outstrips our knowledge.
Like this year's Keables Chair holder, Dr. Scott Kim, Hayashi urges students to look for the as-yet undiscovered patterns and intricacies in the world around them. There are other fields such as hers just waiting to be discovered and investigated by inquisitive, "meandering" minds.
Perhaps one day the title of Genius will be applied to another Iolani graduate.
MacArthur Foundation Citation:
Cheryl Hayashi is a biologist working at the interface of phylogenetics, biomechanics, and materials science to study the architecture, structure, and function of spider silks. Some species of spiders produce as many as six different silks, each with specific mechanical properties and functions; the protein structure of these silks consists of highly repetitive amino acid groups (with variations in these groups accounting for differences in tensile strength and elasticity of the various thread types).
Hayashi investigates the molecular genetic basis within the genome and in the mRNA transcript that gives rise to the repetitive amino acid structure. Her analyses across numerous orb-weaving spider species call into question long-held beliefs about the independent evolution of this behavior.
In addition, her examination of sequence differences between individuals of the same species suggests a “modular” mechanism for genetic variation and selection.
More recently, Hayashi has expanded her studies to include silks from other arthropods (such as caterpillars), non-silk proteins such as glues, and comparative analysis of spider silk biomechanics.
Her findings, already advancing our understanding of spider phylogenetics, also have the potential to influence the development of biomimetic material for a variety of applications, from biodegradable fishing lines to medical sutures to protective armor cloth.
With a deep understanding of spider biology, Hayashi is contributing to a fundamental rethinking of arachnid phylogeny and revealing key information about spider silks to support the development of new synthetic materials.
Cheryl Hayashi received a B.S. (1988) from Yale University and a Ph.D. (1996) through a joint program with Yale University and the American Museum of Natural History. She was a postdoctoral fellow (1996-2001) at the University of Wyoming and, in 2001, became an assistant professor of biology at the University of California, Riverside, where she is now an associate professor. Her scientific articles have appeared in such journals as Science, Proceedings of the National Academy of Sciences USA, and the Journal of Experimental Biology.
