- Author: Kathy Keatley Garvey
Murphy, a fourth-year UC Davis student majoring in neurobiology, physiology, and behavior, received $1563 to study “Codon Optimization: Cracking the Genetic Code.” A codon is a unit of three nucleotides that together codes for an amino acid, the building block of proteins in all organisms. Using the fly, Drosophila melanogaster, as a model system, Murphy is exploring the functional significance of codon bias, a phenomenon in which certain codons are favored over others even though they may code for the same amino acid.
Murphy has worked in the Chiu lab since 2011. “Katie is one of the most talented and hardworking student I have ever encountered,” Chiu said. “I can't think of anyone else who is more deserving of this award.”
Murphy is one of a select group of students in the Research Scholars Program in Insect Biology, organized and directed by professor Jay Rosenheim and assistant professors Louie Yang and Joanna Chiu. The program aims to provide undergraduates with a closely mentored research experience in biology.
The Provost's Undergraduate Fellowship supports undergraduate students doing research or creative projects under the guidance of UC Davis faculty members. Students from all discipline areas are eligible to apply
As a Provost fellow, Murphy will present her work at the annual UC Davis Undergraduate Research Conference, which takes place April 25–26 in Freeborn Hall.
In 2012, Murphy received a UC President's Undergraduate Research Fellowship for her research on "Transgenic Yeast as an Organic Pesticide," exploring the use of RNAi technology in combating the invasive pest, the spotted-wing Drosophila suzukii. She also received a 2013 McBeth Memorial Scholarship and a 2010 Voorhies Memorial Scholarship.
Murphy is a 2010 graduate of Kelseyville High School (Lake County) and valedictorian of her class.
“My favorite subject in high school was biology,” she recalled. “My favorite project was when we dissected a cat in anatomy. In college, I lucked into a lab job where my boss and co-workers were willing to teach me and allowed me the freedom to take on my own projects, an opportunity that few undergrads get.”
Following graduation, she plans to travel and continue her current research projects.
- Author: Kathy Keatley Garvey
The research, “Gradual Molecular Evolution of a Sex Determination Switch in Honeybees through Incomplete Penetrance of Femaleness,” is published in the December edition of Current Biology. The research shows that five amino acid differences separate males from females.
The lead author, Martin Beye, an evolutionary geneticist at the University of Duesseldorf, Germany, was Page’s former UC Davis postdoctoral researcher. Bee breeder-geneticist Michael “Kim” Fondrk provided the genetic material from crosses using Page’s bees that he tends at the Harry H. Laidlaw Jr. Honey Bee Research Facility, UC Davis.
“The story goes back to Johann Dzierson in the mid 1800s through Mendel, through Harry Laidlaw to me and to my former postdoc at Davis, Martin Beye,” Page said.
“Much of the work was done at UC Davis beginning in 1990,” Page said. "From 1999-2000, Martin Beye was a Fyodor Lynen Fellow in my lab funded by the Alexander von Humboldt Foundation. During that year he began the sequencing and characterization of the csd gene; the paper was eventually published as a cover article in Cell."
Said Fondrk: “This project was a long time in making; it began soon after our Cell paper was published in 2003. First we needed to assemble variation for alleles at the sex locus, by collecting drones from many different, presumably unrelated queens, and mating one drone each through an independently reared set of queens using instrumental insemination (which was Fondrk's task). "Then a second set of crosses was made to identify and isolate individual sex alleles. The progeny that resulted from this cross were taken to Germany where Martin Beye’s team began the monumental task of sequencing the sex determination region in the collected samples.”
Silesian monk Johann Dzierson began studying the first genetic mechanism for sex determination in the mid-1800s. Dzierson knew that royal jelly determines whether the females will be queen bees or honey bee colonies, but he wondered about the males.
Dzierson believed that the males or drones were haploid – possessing one set of chromosomes, a belief confirmed in the 1900s with the advent of the microscope. In other words, the males, unlike the females, came from unfertilized eggs.
“However, how this system of haplodiploid sex determination ultimately evolved at a molecular level has remained one of the most important questions in developmental genetics,” Coulombe pointed out in her news release.
The collaborators resolved the last piece of the puzzle.
“Once again, the studies by Dr. Rob Page and his colleagues have unraveled another mystery of honey bee development,” commented Extension apiculturist Eric Mussen of the UC Davis Department of Entomology and Nematology, who was not involved in the study but knows the work of many of the collaborators. “It would be interesting if someone investigated the same type of sexual dimorphism in other hymenopterans to determine if they all use the same, ancient-based mechanism.”
The authors studied 14 natural sequence variants of the complementary sex determining switch (csd gene), for 76 genotypes of honey bees.
“However, the questions of which alleles were key, how they worked together and in what combinations and why this system evolved were left unanswered, though tantalizing close. This compelled the current team of collaborators to step back to review what actually constitutes an allele.”
Page was quoted in the news release: “There has to be some segment of that gene that is responsible in this allelic series, where if you have two different coding sequences in that part of the gene you end up producing a female. So we asked how different do two alleles have to be? Can you be off one or two base pairs or does it always have to be the same set of sequences? We came up with a strategy to go in and look at these 18-20 alleles and find out what regions of these genes are responsible among these variants.”
“In this process,” Page said, “we also had to determine if there are intermediate kinds of alleles and discover how they might have evolved.”
“What the authors found,” wrote Coulombe, “was that at least five amino acid differences can control allelic differences to create femaleness through the complementary sex determiner (csd) gene – the control switch.”
Page explained: “We discovered that different amounts of arginine, serine and proline affect protein binding sites on the csd gene, which in turn lead to different conformational states, which then lead to functional changes in the bees – the switch that determines the shift from female to not female.”
The authors also discovered a natural evolutionary intermediate that showed only three amino acid differences spanned the balance between lethality and induced femaleness, Coulombe wrote. The findings suggest that that incomplete penetrance may be the mechanism by which new molecular switches can gradually and adaptively evolve.
Other co-authors included Christine Seelmann and Tanja Gempe of the University of Duesseldorf; Martin Hasslemann, Institute of Genetics at the University of Cologne, Germany; and Xavier Bekmans with Université Lille, n France. Grants from the Deutsche Forschungsgemeinschaft supported their work.
Page, who studies the evolution of complex social behavior in honey bees, from genes to societies, received his doctorate in entomology from UC Davis in 1980, and served as an assistant professor at Ohio State University before joining the UC Davis Department of Entomology in 1989. He chaired the department for five years, from 1999 to 2004 when ASU recruited him as the founding director and dean of the School of Life Sciences, an academic unit within College of Liberal Arts and Science (CLAS).
Page was selected the university provost in December. He had earlier served as the vice provost.
Recognized as one of the world’s foremost honey bee geneticists, Page is a highly cited entomologist who has authored more than 230 research papers and articles centered on Africanized bees, genetics and evolution of social organization, sex determination and division of labor in insect societies. His work on the self-organizing regulatory networks of honey bees is featured in his new book, The Spirit of the Hive: The Mechanisms of Social Evolution, published in June 2013 by Harvard University Press.
- Author: Kathy Keatley Garvey
DAVIS--Honey bee guru Eric Mussen, Extension apiculturist at the UC Davis Department of Entomology and Nematology who will be retiring at the end of June, has seen and used many a smoker during his 38-year career.
But this one is different.
In honor of his service, the California State Beekeepers’ Association recently presented him with a plaque decorated with a smoker “for 38 years of work and support.”
Throughout his career, Mussen has offered advice to scores of people and figuratively put out many a fire involving beekeeping and pollination issues.
A smoker, a device that beekeepers use to calm honey bees so they can open their hives, masks the smell of the alarm pheromones released by guard bees. It also prompts the bees to gorge on honey.
Considered by his peers as one of the most respected and influential professional apiculturists in the nation, Mussen presented a slide show of some of the highlights of his career during his two-hour presentation on “The Most Interesting Time in Beekeeping.”
“I got carried away,” Mussen said later. “I was nearly at the end of the second hour when I was asked to wrap up my 45-minute presentation. Many listeners said that they still hope to hear the ‘more current’ portion that had to be omitted.”
Mussen has given presentations to CSBA since joining the UC Davis faculty in 1976. He is also the organization’s apiculturist and parliamentarian and served as a delegate to the American Beekeeping Federation.
A native of Schenectady, N.Y., Mussen received his bachelor’s degree in entomology from the University of Massachusetts (after turning down an offer to play football at Harvard) and then received his master’s degree and doctorate in entomology from the University of Minnesota in 1969 and 1975, respectively.
His doctoral research focused on the epidemiology of a viral disease of larval honey bees, sacbrood virus.
Mussen continues to tackle many new challenges regarding honey bee health and pollination concerns, including mites, diseases, pesticides, malnutrition, stress, Africanized honey bees and the successful pollination of California’s almond acreage.
Mussen educates the beekeeping industry and general public with his bimonthly newsletter, from the UC Apiaries, which he launched in 1976. Since 1976, he has also written Bee Briefs, addressing such issues as diseases, pesticides and swarms. Both publications are on the departmental website at http://ucanr.org/sites/entomology/Faculty/Eric_C_Mussen/Apiculture_Newsletter/.
The recipient of numerous state and national awards, Mussen is a worldwide authority on honey bees, said Jackie Park-Burris, a commercial queen breeder in Butte County and a past president of the California State Apiary Board.
Mussen is known for devoting his research and extension activities toward the improvement of honey bee health and honey bee colony management practices. He helps growers, consumers, UC Farm Advisors, agricultural commissioners, scientists, beekeepers, researchers, pesticide regulators, 4-H’ers, and state and national agricultural and apicultural organizations, among others.
"I am basically all pro-bee,” Mussen told the American Bee Journal in a two-part feature story published in the September of 2011. “Whatever I can do for bees, I do it...It doesn’t matter whether there is one hive in the backyard or 15,000 colonies. Bees are bees and the bees’ needs are the bees’ needs.”
Recruitment is underway for his successor, who will begin as an Extension assistant apiculturist.
- Author: Kathy Keatley Garvey
DAVIS--Ecologist Rick Karban, professor in the UC Davis Department of Entomology and Nematology, is featured in the Dec. 23-30 edition of The New Yorker in Michael Pollan’s piece, “The Intelligent Plant: Scientists Debate a New Way of Understanding Plants.”
Karban studies volatile (chemical) communication between plants that affect their defenses against herbivores. Pollan wrote that he met Karban in Vancouver, British Columbia, last July when Karban was presenting a paper on “Plant Communication and Kin Recognition in Sagebrush” at the sixth annual meeting of Society for Plant Neurobiology, now the Society for Plant Signalling and Behavior.
For The New Yorker feature, Pollan interviewed scientists on a number of plant intelligence topics, including decision-making. “Plants perceive competitors and grow away from them,” Karban told Pollan. “They are more leery of actual vegetation than they are of inanimate objects, and they respond to potential competitors before actually being shaded by them.”
Pollan wrote that “Plants speak in a chemical vocabulary we can’t directly perceive or comprehend. The first important discoveries in plant communication were made in the lab in the nineteen-eighties, by isolating plants and their chemical emissions in Plexiglas chambers, but Rick Karban, the U.C. Davis ecologist, and others have set themselves the messier task of studying how plants exchange chemical signals outdoors, in a natural setting.”
Pollan toured Karban’s sagebrush study plot at the UC Sagehen Creek Field Station, near Truckee. Karban has been researching the plant/herbivore interactions since 1999.
Karban recently drew widespread scientific and media attention with research that he and four colleagues published in February 2013 in the Proceedings of the Royal Society B: Biological Sciences. Their research showed that kin have
distinct advantages when it comes to plant communication, just as “the ability of many animals to recognize kin has allowed them to evolve diverse cooperative behaviors,” he said in a news release published by the UC Davis Department
of Entomology and Nematology.
“When sagebrush plants are damaged by their herbivores, they emit volatiles that cause their neighbors to adjust their defenses,” Karban said in the news release. “These adjustments reduce rates of damage and increase growth and survival of the neighbors.”
“Why would plants emit these volatiles which become public information?” he asked. “Our results indicate that the volatile cues are not completely public, that related individuals responded more effectively to the volatiles than did strangers. This bias makes it less likely that emitters will aid strangers and more likely that receivers will respond to relatives.”
The research, “Kin Recognition Affects Plant Communication and Defense,” was co-authored by two scientists from Japan and two from UC Davis: Kaori Shiojiri of the Hakubi Center for Advanced Research, Kyoto University, and Satomi Ishizaki of the Graduate School of Science and Technology, Niigata University; and William Wetzel of the UC Davis Center for Population Biology, and Richard Evans of the UC Davis Department of Plant Sciences.
To simulate predator damage, the researchers “wounded” the plants by clipping them and then studied the responses to the volatile cues. They found that the plants that received cues from experimentally clipped close relatives experienced less leaf damage over the growing season that those that received cues from clipped neighbors that were more
distantly related.
“More effective defense adds to a growing list of favorable consequences of kin recognition for plants,” they wrote.
Karban is a fellow of the American Association for the Advancement of Science (AAAS) and has published more than 100 journal articles and two books.
Links:
Kin Recognition Affects Plant Communication and Defense
- Author: Kathy Keatley Garvey
The exhibition includes bronze stick insects and a series of digital prints of colorful cockroaches.
The opening reception will be from 5 to 7 p.m. on Friday, Jan. 24. Shelomi will be there to answer questions. The gallery is located in the South Silo building.
Shelomi, who studies with major professor Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis, has volunteered at the Craft Center since his graduate school enrollment at UC Davis in the fall of 2009. He has taken many of the evening and weekend classes offered there, from flame-working to wood-turning to bookbinding.
The most popular items are his bronze stick insects. Shelomi’s dissertation is on the digestive physiology of stick insects (Phasmatodea), for which he uses the many phasmids reared at the Bohart Museum for research and for public display.
How does he make the bronze replicas?
When a stick insect dies (of natural causes), Shelomi takes the hard exoskeleton to the Craft Center, mounts it with wax channels called “sprues,” and embeds it in plaster. He then heats the combination in a kiln until all organic matter, including the insect, is burned away, leaving a plaster mold with a cavity in the shape of a stick insect.
Shelomi then pours the molten metal, such as bronze or pewter, into the mold using a spin-caster machine. Each mold can be used only once, but the result is a metal copy of the insect with most of the details, from the spines to the delicate mouthparts, fully preserved.
Another display in the exhibition is a series of digital prints of colorful cockroaches, from pinks to greens to blues. These were made by injecting some of the feeder cockroaches used in the Bohart Museum with histological dyes, a process known as “vital staining” that played a big role in Shelomi’s dissertation research. Each stain colors different tissues of the insect with different intensities, and can be used to identify anatomical features.
Other pieces include relief prints of cicadas, ceramic ants, and an oil painting of a Carabid beetle, as well as several works that are not entomology inspired, but showcase “the variety of media and materials one can work with at the Craft Center,” Shelomi said.
Some of the pieces at Shelomi’s solo exhibition will be available for purchase after the show. For more information, contact Matan Shelomi at mshelomi@ucdavis.edu.
Shelomi, active in entomological circles, received the 2013 John Henry Comtock Award from the Pacific Branch of the Entomological Society of America (ESA) and was a member of the UC Davis debate team that won the national 2013 ESA Student Debate championship. He regularly answers entomological questions on Quora.
The Craft Center, which offers more than 90 classes each quarter, is open on Thursdays from 12:30 to 10 p.m.; on Fridays from 12:30 to 7 p.m.; and on Saturdays and Sundays from 10 a.m. to 6 p.m. More information on the craft center is available on the website.
Related Links:
- Matan Shelomi and the Stick Insects
- Matan Shelomi's Shorty Award
- Cutting Bergmann's Rule Down to Size
- Taking a Poke at Pokemon
- NSF Grant