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Raúl Cano is a professor of microbiology at California Polytechnic State University in San Luis Obispo, Calif. In 1995, he and colleagues in his lab stunned the world when they announced they’d revived 30-million-year-old bacteria from spores taken from the gut of an ancient bee entombed in amber. There were skeptics who wondered whether the bacteria were really just modern bugs that contaminated the tools used to get at the bee gut tissue. But in October 2000, another research group used many of the techniques developed by Cano’s lab to revive 250-million-year-old bacteria from spores trapped in salt crystals. With this additional evidence, it now seems that the "impossible" is true.
Cano has received several awards for his outstanding teaching skills and is recognized for his laboratory training of undergraduate students. This is his story of how he went from living in Cuba to becoming an American citizen, from hating biology to loving it, and from planning to be a doctor to becoming a scientist.
"There have been times in my life when microbiology was not a high priority, but not too many! I am sometimes asked to reflect on the chosen path of my life and queried about how I would live my life differently should the opportunity arise. Without reservation, I would do as I did because I am satisfied with the direction my life has taken.
Career goals were not a high focal point for me when I was growing up in Havana, Cuba. It was assumed, even by me, that I was to follow in my father’s footsteps and become a physician. I attended a parochial school whose primary mission was to make sure I did just that. Then, in 1959, all these plans were put on hold when Fidel Castro took control of the Cuban government. In 1962, at sixteen years of age, I immigrated alone to Miami, Florida, in hopes of continuing my education. While at a refugee camp in the Everglades of Florida, I continued my high school education and began learning the English language. One of my least favorite subjects was biology, so I started to think that becoming a physician wasn’t such a good idea.
In May 1962 I was relocated to Spokane, Washington, where my life as an "American" really began. I enrolled at Gonzaga University as a chemical engineering major, but a combination of homesickness, inability to understand English, the Cuban missile crisis, and the Vietnam War prevented me from focusing on my studies, and as a consequence I did not do too well. Thus, up to this point, my academic career was not the resounding success my parents (and I) had expected. From 1963 until 1968, I worked as a physical therapy and surgical orderly in a local hospital. After much deliberation, I decided to pursue a career as a physical therapist.
In 1968, after a brief stint in the Army, I married my wife, Pat, and returned to college, this time for good as it turned out, ready to become a physical therapist. At Eastern Washington University, I took the required chemistry and math courses and did well, but my nemesis—biology—continued to hound me. I was frustrated with my inability to dominate this subject, especially genetics, until I took a course in microbiology from a first-year faculty member named Norman Vigfusson (my idol). Dr. Vigfusson was a high school teacher who decided to pursue a microbial genetics career well into his thirties (a veritable old man).
My first college-level microbiology course was a career-maker. After so much frustration and failures, I fell in love with microbiology. I was absolutely certain that I wanted to be a microbiologist when I grew up. So, I informed my wife, apologized to my parents, and immersed myself into becoming a competent microbiologist. I’m still working at it!
My first exploration into microbiological life was with Neurospora crassa. My mentor, Dr. Vigfusson, studied the genetics of the life cycle of this fungus as part of his doctoral dissertation. My senior project was to study the first step in fertilization of the female gamete and to see if there were any chemical signals (pheromones) involved in making the female organs receptive to the male gamete. . . . I learned a bunch of biology and discipline along the way. I continued my explorations of the sexual development cycle in Neurospora crassa for my master’s thesis. My efforts culminated in my first publication in Nature.
From that point on, I was hooked! In 1972 I entered the laboratory of my second "idol," John J. Taylor at the University of Montana. To this man, too, I owe a big debt of gratitude. He taught me the scientific method and the precision of scientific nomenclature, but more important, he instilled in me a deep respect for life and for the awesome diversity of microbial life on our planet. This respect and appreciation have motivated me to explore hidden microbial habitats and to study the diversity of microbial life throughout my career.
I received my Ph.D. in 1974 and was fortunate enough to be offered a tenure-track position in the Department of Biology at California Polytechnic State University in San Luis Obispo, which I accepted without hesitation. Through my early years at Cal Poly, I focused on becoming a microbiologist and developing my teaching skills. I moved through the ranks and became a full professor in 1983.
One summer day in 1984, while I was mowing my lawn, I had a thought that changed my life dramatically. I decided to take a sabbatical leave and rediscover my roots. In 1985 my family and I went to Seville, Spain, where I was to spend my sabbatical working with José Carlos Palomares and Evelio Perea at the University of Seville. Under the tutelage of these two fine scientists and, more important, with their friendship, I learned the rudiments of molecular and clinical microbiology. I actually extracted DNA! Moreover, for the first time in my career, I directed the research of a Ph.D. candidate. During that year, I truly learned the value of a teaching experience that integrated research in the learning experience. This experience was so powerful and rejuvenating that I resolved to return each year—a commitment I have never violated.
Needless to say, I was heartbroken when I had to return to my professorial duties at Cal Poly, but I was resolved to change my approach to teaching and to include research in the learning experience of my students. [My] laboratory slowly developed into a first-class molecular biology laboratory and has served as a "home away from home" to more than 500 students.
A central goal of the [lab’s] research projects was to provide undergraduate students with extensive experience in all aspects of a meaningful research project, to pique their scientific curiosity, and to teach them the scientific method. One such project was again to change my life. It started innocently enough with a simple question. How old can DNA still be analyzable? To that end, Hendrik Poinar, a biochemistry undergraduate student at the time, obtained some amber samples from his father, and together we developed a protocol that would prevent the contamination of the amber samples with modern DNA and microorganisms in the environment. At first we were unsuccessful, but after a few tries, we obtained sufficient DNA from bee tissue trapped in amber from the Dominican Republic (20-35 million years old) that could be analyzed by DNA hybridization and amplified by the polymerase chain reaction (PCR). We published this study in an obscure journal, but it gave us the hope that a better, more controlled experiment could be designed and carried out under even more stringent conditions.
Hendrik obtained a piece of Middle Eastern amber (from about 120 million years ago) containing a weevil and proceeded to extract its DNA. . . . This allowed us to carry out phylogenetic studies and determine that the DNA extracted was most closely related to modern weevils. This discovery captivated the nation (and the world) and initiated a great deal of scientific dialog.
The publication of our results in Nature coincided with the release of the movie Jurassic Park, and it created a great deal of media frenzy. This notoriety was definitely a double-edged sword. It created havoc with the everyday operation of the lab, but the publicity also attracted top-notch students to the laboratory.
There was also controversy, and well there should have been. After all, how can we be sure that the DNA we extracted was indeed from the ancient weevil and not from modern sources? This question has not yet been answered to the satisfaction of the scientific community, and in my estimation, it will never be. How can you use negative results to support a hypothesis?
They say that everyone has his or her 15 minutes of fame. Well, I have had two periods of 15 minutes of fame in my career (and I think two is quite enough!). While Hendrik was working on DNA, another student, Monica Borucki, and I were working on the possibility that viable spore-forming organisms were trapped inside the amber. This possibility insinuated itself in my consciousness after viewing some electron photomicrographs of abdominal tissue from an amber-entombed bee. There, in plain view, were endospores with obvious exposporia and a seemingly intact matrix. They really did not look much different from electron photomicrographs of modern Bacillus megaterium endospores.
With this observation as the motivating force, we again toiled over the proper experimental design to [avoid] environmental contamination of the amber samples. To further reduce the possibility of contamination, we extracted and cultured gut tissue under stringent containment conditions, having a fair idea of the gut’s microbial flora in modern bees. From this experiment we isolated a culture of Bacillus sphaericus that, to this date and after numerous verifying experiments, we think originated from the amber inclusion. The hypothesis that this organism resided in viable form in the gut of the bee has never been disproved.
After the onslaught of publicity and worldwide attention (and scrutiny) after the publication of our discovery in Science, there have been, as expected, a considerable number of challenges to our claims, but in this case, the scientific method has smiled on us. There have been at least three independent verifications of the isolation of a living microorganism from amber.
Since 1986, when I returned from Spain as a changed man, I have focused on becoming a microbiology teacher and sharing with my students the wonders of microbial life. During that time, I have developed a philosophy of teaching microbiology with the premise that in order to be a successful teacher, you have to be a successful researcher. The scholarships of discovery, application, and teaching have to merge into one to be truly useful. In the classroom, students can learn the fundamentals, but they must apply their knowledge, not only in experiments with known outcomes, but also in a discovery environment. There they have to apply their theoretical knowledge to formulate a hypothesis, develop experiments to test the hypothesis, perform the proper methodology well, and interpret the results. After all, microbiology is a science of "learning by doing."
This philosophy has guided my career since 1986. I have taught and investigated as hard as I could with all the strength that I had. These efforts have been rewarded by the high quality of students who leave my laboratory and their subsequent professional achievements. But my greatest reward has been the recognition of my efforts by my peers, the professional microbiologists. When I was named a Fellow of the American Academy of Microbiology, my research accomplishments were recognized, but when I was awarded the 1997 Carski Foundation Distinguished Teacher Award, I received the greatest accolade of all: I was recognized as a teacher!"
(This profile is taken from a book called Many Faces, Many Microbes, a collection of personal essays written by a wide variety of microbiologists.)