Life Sciences in the College Today - A Sampler

Rex Cates

Professor Rex CatesRex Cates teaches general biology; he and his students research medicinal plants used by rural people in such places as Morocco, Guatemala, Ecuador, and the U.S. desert southwest. They focus on plant extracts that have reduced toxicity to normal human cells but that are active against diseases such as herpes virus, E-coli, various cancers, Staphylococcus, and yeast infections. "Of the 200 plants and lichens tested, about 20% have yielded promising extracts, and four of these are extremely promising," Cates said.

Desert southwest paper flower plant
Mary Greer, a Ph.D. student working with Cates and colleague Brent Johnson has found that extracts from the desert southwest "paper flower" plant (aster family) completelyprotect mammalian cells against infection by the Herpes I virus
"My favorites are species in the mint and sunflower families" he said. "They're loaded with essential oils that protect them from diseases and predators. Our work has shown many of these plants have important activity against human diseases, and low toxicity to normal cells."

"About 75% of the earth's population relies on plants as their primary health care sources." Cates said. "Unfortunately much of their traditional knowledge regarding the use of these plants is disappearing. We hope to document a great deal of that knowledge before it's lost. And since most of the people who have this knowledge live in poverty; we have encouraged local support to help develop these plants into cash crops."




Beverly Roeder


Professor Beverly Roeder
Beverly Roeder is the pre-veterinary medicine advisor for the College and teaches animal-related biology courses. At BYU, she oversees a veterinary clinic where students assist in the care of stray and abandoned animals. Roeder also works with students and a colleague in Chemical Engineering performing research with ultrasound to target release of microencapsulated cancer chemotherapy. When the ultrasound is turned off, the drug reencapsulates, preventing damage to healthy tissues and the cardiovascular system.

Professor Roeder collecting information of a black bear mother
Roeder, colleagues, and students are collecting nutritional information from blood and hair samples to determine nutritional status and history of a black bear mother.
Roeder also studies the nutrition and health of black bears and sun bears. "Southeast Asian sun bears are endangered due to habitat loss to farming, urbanization, and poaching for gallbladders believed to contain medicinal properties," Roeder said. She and her students are studying sun bears in zoos to determine the relative importance of different food groups by studying isotopic ratios in their metabolic substrates. "We want to determine if endangered sun bears maintained in enclosed nature reserves are receiving the nutrients they need to remain healthy and reproduce compared to what free-ranging sun bears access in their wild ecosystem," Roeder said.





Joel Griffitts

Professor Joel GriffittsJoel Griffitts teaches bacterial genetics at BYU and investigates interactions between bacteria and plants. "Special bacteria right under our feet collaborate with legumes in amazing ways," he said. "The whole living world would not be what it is without this unique interaction."

Alfalfa plant in test tube.
Pink nodules containing bacteria. Colonies of genetically-engineered bacteria
A 20 day-old alfalfa plant (in test tube) has been inoculated with nitrogenfixing bacteria. Pink nodules each containing thousands of symbiotic bacteria are developing on the roots (upper inset); colonies of genetically-engineered bacteria turn blue when expressing a gene required for symbiotic roots infection (lower inset).
Griffitts focuses on soil-borne bacteria called rhizobia that infect the roots of alfalfa. Rather than counter the invasion, the infected plant builds a home (a fleshy root nodule) for the rhizobia. "Once within the alfalfa root the bacteria change," Griffitts said. "They transform themselves   and take on the capacity to convert nitrogen from the air into fertilizer for the plant."

"These organisms don't have brains or voices, yet they are able to communicate with each other and establish a very close and cooperative relationship," Griffitts said. "How do they recognize one another? What triggers new genes to be expressed and a differentiation event to occur once the bacteria encounter the plant?"

"My vision," Griffitts continued, "is that we will be able to identify the full suite of plant and bacterial functions that allow a symbiotic interaction to occur. Perhaps one day we will be able to transfer what we know about this system to cereal crops that don't naturally engage these bacteria the way legumes do."




David Erickson


Professor David Erickson
David Erickson teaches medical microbiology and researches the transmission of bubonic plague or "black death" by fleas. He studies the infection process and is interested in genes that help the plague bacteria make their way from the mammal to the flea and back again.

Rat flea
Plague bacteria infecting this rat flea have formed sticky clumps that have blocked its foregut, preventing the flow of fresh red blood into the midgut. This process improves plague transmission efficiency.
Erickson notes that once inside the flea, the plague bacteria produce a sticky bio-film that conglomerates to plug the flea's esophagus so that the flea starves. He is interested in the polysaccharide glue that binds the bacteria in the flea's esophagus. When the cold-blooded flea feeds on a human, plague bacteria are first injected in clumps held together by the glue, but once in the warm-blooded human the glue is soon dissolved. Erickson proposes a vaccine that attacks the glue form, so that as soon as the body encounters it, and before the glue has a chance to melt, the bacteria are attacked. In other words the vaccine would act against the flea version rather than the human version of the plague.

"Applications will come out of this basic research," Erickson said. "They now have transgenic mosquitoes that are incapable of transmitting diseases. Flea research and the bacteria associated with the plague are less advanced."



Susan Fullmer


Susan Fullmer
Susan Fullmer teaches clinical nutrition and sports nutrition; her research focuses on women and bone density. She notes that low bone density has been observed in both sedentary and superactive women. "Women who over-exercise can have poor bone mass," she said. "It can occur even in young adulthood."

Student Katrina Cummins assisting study participant Shirley Cox
Student Katrina Cummins assists study participant Shirley Cox complete exercises designed to strengthen bones of the female spine.
With moderation, bones become stronger when they are exposed to greater loads, either from gravity or from working muscles attached to bone. Fullmer notes that when women do typical recreation or aerobic exercises they work their arms and legs, but might not adequately load the spine.

"High-intensity, high-volume total upper body circuit training which might be done to increase spinal bone density is risky because it places high compressive loads on the vertebral discs," Fullmer said. "Further, they usually require subjects to travel to a gym for work outs."

Fullmer has come up with and is now testing a series of nine exercises designed to safely strengthen the bones of the female spine. Instead of exercising with weights from above the head, these exercises isolate abdominal and lower back muscles attached to the lumbar spine. She and her students are recruiting 100 post-menopausal women for an exercise group or for a sedentary group.


Robert Davidson


Professor Robert Davidson
Robert Davidson teaches nutritional biochemistry. While on his college ROTC Rifle Team he worked out his first computer model which simulated bullet trajectory. In graduate school he became interested in dynamic modeling for the health sciences.

Human energy-balance and body-weight model
This dynamic human model shows changes that will occur in a specific woman's body (left) if she continues with her current diet and exercise regime for another ten years.
"NASA has the machinery capable of taking a man to Mars," Davidson said, "but we don't have the information necessary to keep the man healthy and alive throughout the 3-year round trip. Dynamic modeling is a safe approach."

At BYU he and his students have developed a human energy-balance and body-weight model which can be customized to any individual by taking measurements and documenting their diet and exercise regime. They can predict weight gain or loss, and where on the body that gain or loss will occur.

They're now working to predict changes in specific muscle mass and human performance. They hope to analyze specific diets (such as high protein, low carb) and predict which will be most effective for any individual person. "This is new territory research that is very conducive to undergraduate assistance," Davidson said. "It involves high-level math, but almost all the metabolic information is available in the literature. The sports industry, the military, and
NASA should all be interested in our results."



John Bell

Professor John Bell
John Bell teaches freshman biology and is associate dean over education. He and his students study an enzyme called phospholipase A2 which is present in blood and aids in digesting fats. The enzyme also assists in the breakdown of sick or damaged cells, and is one of the components of snake venom, helping digest whatever the snake kills and eats.

Human red blood cell
This human red blood cell is self destructing after receiving a chemical signal indicating that its services are no longer needed.
"We want to know how the enzyme tells the difference between sick and healthy cells," Bell said. "This is important because when cells are treated with chemotherapy they become susceptible to this enzyme. The body needs to clear out unwanted cells in the case of sickness or trauma, but not degrade healthy cells or non-tumor cells during chemotherapy. We've determined that there is a change in the membrane structure of damaged cells which initiates susceptibility to this digestive enzyme."

Because entire experiments can be done in a few hours, Bell's research is very amenable to students. There are commonly four or more student authors on his research publications, each having done their part. "The contributions my lab makes to science are small compared to its role in preparing students to leave BYU and have important impact elsewhere," Bell said.




Jim Porter


Professor Jim PorterJim Porter teaches physiology and researches the fetal origins of adult disease. His hypothesis is that environment during pregnancy reprograms the genes of the fetus which impact the individual throughout life. He focuses on cardiovascular health. Porter fed
Mother rat with pubs
The mother rat is on a normal diet but was fed a high-salt diet while she was pregnant. Her nursing pups show signs of being affected by their mother's previous food intake.
pregnant rats a diet high in salt throughout pregnancy. Upon delivery mothers returned to a normal diet. Tiny radio transmitters were implanted into an aorta of nursing babies to monitor blood pressure and heart rate throughout their life without disturbance.

Porter and his students have found that female rats that were gestated on high salt and later stressed (by placing them for an hour in a Plexiglas tube), had significantly higher blood pressure and heart rate than rats gestated on a normal diet [it's called hyper-responsiveness to an acute stress]. Out of about 30,000 genes they're now investigating just one gene that appears to be involved; it is also found in humans. "It appears that the mother is not passing on salt itself to her babies," Porter said, "but rather she's passing on some sort of genetic signal which affects her pups later in life. The response seems to be originating in the brain."



Josh Udall


Professor Josh Udall
Dr. Josh Udall teaches genetics and genomics (the study of an organism's total hereditary information). He works to improve salt and drought tolerance in cotton. One variety he studies grows wild in Hawaii directly in salt spray; it is used as a source of salt and drought tolerance in agriculture but the genes involved are unknown.

Cotton plants
Udall is crossing cultivated cotton to wild forms (left) to identify and recover valuable genes that may have been left behind during the domestication process.
"Cotton is a diploid, meaning it carries two copies of all genes," Udall said. "If tolerance to salt appeared to be derived from just one copy, it might be possible to activate both copies and enhance resistance; or we may be able to silence a gene copy that is making cotton susceptible to stress."

Udall and his students work at the molecular level. They use a technique called 'micro-arrays' to measure the expression of thousands of genes at a time. Genes are arrayed in rows and columns as spots on a glass microscope slide. DNA is then fluorescently labeled and hybridized to the micro-array. When scanned with a laser a spot lights up if it contains sought-after DNA. "If we identify genes associated with salt stress in the lab, we can probably use them to improve cotton performance in the field," Udall said.



Tom Smith


Professor Tom SmithTom Smith teaches a variety of wildlife ecology courses. He and his students are studying bear ecology and bear-human interactions. Due to decreasing pack ice, polar bears are increasingly denning along Alaska's North Slope, at a time when high oil prices are fueling increased exploration. Smith studies polar bear's denning ecology and whether or not exploratory activities adversely impact bears. To study them, however, you must first find them.

Professor Tom Smith with tranquilized polar bears
Smith tranquilized this polar bear family prior to taking cub weight and sex, plus blood samples, fecal and nasal swabs for lab analysis
"It's difficult to locate bears denned beneath the snow," Smith said.  "We've been successful using helicopters and infrared cameras. Any source of warmth in the snow is a pretty good indication of life; nothing else will cause heat in a -50° landscape." He is pursuing research that will result in more effective means of finding dens.

"It's brutal work in a bitter environment," Smith said, "but it's rewarding to see students engaged in understanding and helping preserve one of the planet's most magnificent creatures."

Smith also studies bear-human conflict. A 15 year study of bear attacks in Alaska is revealing previously unseen patterns. "I've accumulated nearly 600 incidents of bear attacks spanning 125 years. In-depth analysis is yielding insights that will help bears and humans more peaceably co-exist in the Last Frontier."