The paper on bee immunity and toxin metabolism was published Nov. 9 in Scientific Reports, part of the Nature Publishing Group.
“First, the results suggest that forager bees may use antimicrobial peptides—short sequences of amino acids with general activity-- to reduce microbial growth in stored food resources,” said Rachel Vannette of the UC Davis Department of Entomology and Nematology. “This would be a largely unrecognized way that bees protect honey and potentially other stored resources from microbial spoilage. Second, this work shows that forager bees produce toxin-degrading enzymes in nectar-processing tissues.”
“This may allow forager bees to degrade many different kinds of compounds in nectar, before it is stored,” Vannette said. “Bees also vary in their ability to do this—foragers have a greater ability to degrade a variety of compounds than nurses. This may have implications for hive health and management.”
"Nice paper,” said Gene Robinson, director of the Institute for Genomic Biology and Swanlund Chair of Entomology, University of Illinois at Urbana-Champaign, who was not involved in the research. “It had been well known that the division of labor in a honey bee colony is supported by extensive differences in brain gene expression between bees that perform different jobs. This new research shows nicely that this genomic differentiation extends beyond the brain; different complements of active genes in a variety of tissues make each bee better suited for the job it needs to perform."
The journal article, titled “Forager Bees (Apis mellifera) Highly Express Immune and Detoxification Genes in Tissues Associated with Nectar Processing,” is the work of senior author/assistant professor Brian Johnson of the UC Davis Department of Entomology and Nematology, and co-authors Abbas Mohamed, graduate student researcher in the Johnson lab and a member of the Pharmacology and Toxicology Group, and assistant professor Vannette, who joined the UC Davis Department of Entomology this fall after serving a postdoctoral fellowship at Stanford University. At Stanford, Vannette examined the role of nectar chemistry in community assembly of yeasts and plant-pollinator interactions.
Johnson, whose research interests include animal behavior, evolution, theoretical biology and genomics, recently began long-term research on the honey bee immune system and the causes and consequences of economically important diseases /syndromes such as colony collapse disorder.
Mohamed, who has researched honey bees since 2011, is currently focusing on pesticide detoxification as a part of his master's degree research. "Honey bees have always fascinated me,” Mohamed said, “and there is nothing more exciting than to be at the edge of discovery, learning new things, and contributing to the field of our understanding of these amazing creatures.”
The team plans to follow up with functional assays to examine the potential of these gene products to (1) reduce microbial growth and (2) degrade a variety of natural and synthetic compounds.
“Pollinators, including honey bees, routinely encounter potentially harmful microorganisms and phytochemicals during foraging. However, the mechanisms by which honey bees manage these potential threats are poorly understood. In this study, we examine the expression of antimicrobial, immune and detoxification genes in Apis mellifera and compare between forager and nurse bees using tissue-specific RNA-seq and qPCR. Our analysis revealed extensive tissue-specific expression of antimicrobial, immune signaling, and detoxification genes. Variation in gene expression between worker stages was pronounced in the mandibular and hypopharyngeal gland (HPG), where foragers were enriched in transcripts that encode antimicrobial peptides (AMPs) and immune response. Additionally, forager HPGs and mandibular glands were enriched in transcripts encoding detoxification enzymes, including some associated with xenobiotic metabolism. Using qPCR on an independent dataset, we verified differential expression of three AMP and three P450 genes between foragers and nurses. High expression of AMP genes in nectar-processing tissues suggests that these peptides may contribute to antimicrobial properties of honey or to honey bee defense against environmentally-acquired microorganisms. Together, these results suggest that worker role and tissue-specific expression of AMPs, and immune and detoxification enzymes may contribute to defense against microorganisms and xenobiotic compounds acquired while foraging.”
He will receive an award of $16,000 to be used in support of his research activities. The Hellman Family Foundation established the UC Davis Hellman Fellows Program, which "supports and encourages the research of promising assistant professors who exhibit potential for great distinction in their research." Johnson's project title: "Genetic Mechanisms Underlying the Evolution of Novelty."
A luncheon honoring him and the other 11 UC DavisHellman Fellows is planned in late April or early May, said Lynn Daum of the UC Davis Vice Provost office, Academic Affairs. They will give a short presentation about their research.
Johnson is the second faculty member in the Department of Entomology and Nematology to receive the honor. Community ecologist Louie Yang received the distinction in 2012 as an assistant professor and is now an associate professor.
Johnson, who joined the UC Davis Department of Entomology and Nematology faculty in 2011, received his doctorate in 2004 from Cornell University, Ithaca, N.Y. in behavioral biology (thesis: “Organization of Work in the Honey Bee”). He obtained his bachelor's degree in 1998 from the UC San Diego, where he majored in ecology, behavior and evolution.
"Our lab studies the genetics, behavior, evolution, and health of honey bees. We use experimental and theoretical approaches to all the questions we explore," he writes on his website. "Current work in our lab focuses on the evolution and genetic basis of social behavior using comparative and functional genomics, task allocation using behavioral and theoretical approaches, and honey bee health using a combination of genetics, epidemiology, and physiological approaches."
The complete list of Hellman Fellows for 2015 from the UC Davis campus:
- Brian Johnson, assistant professor, Entomology and Nematology
- Shu Shen, assistant professor, Economics
- Nicholas Zwyns, assistant professor, Anthropology
- Jessica Bissett Prerea, assistant professor, Native American Studies
- Chunjie Zhang, assistant professor, German and Russian
- Cassandra Hart, assistant professor, Education
- Siwei Liu, assistant professor, Ecology
- Danielle Stolzenberg, assistant professor, Psychology
- Helen Koo, assistant professor, Design
- Margaret Ronda, assistant professor, English
- Kevin Gee, assistant professor, Education
- Brett Milligan, assistant professor, Landscape Architecture, Human Ecology
He will be hosted by fellow bee scientist Brian Johnson, assistant professor, UC Davis Department of Entomology and Nematology.
Zayed leads a research program on honey bee behavioral genetics and genomics. In his talk, Zayed will summarize his group's recent findings on patterns of positive selection in the honey bee genome, and show how integrative genomic analyses can be used to chart the bee's genotype-phenotype map.
Zayed completed his bachelor's degree in environmental science with honors in 2000, and his doctorate in biology in 2006, both at York University. He was awarded the Governor General's prestigious Gold Medal in 2007 for his doctoral research on bee conservation genetics.
Zayed held a Natural Sciences and Engineering Research Council of Canada's Postdoctoral Fellowship at the University of Illinois' Department of Entomology from 2006 to 2008 in Charles Whitfield's Laboratory. He then served as a fellow for the Institute for Genomic Biology's Genomics of Neural and Behavioral Plasticity Theme (theme leader: Gene Robinson) at the University of Illinois from 2008 to 2009.
Zayed rejoined York University's Department of Biology as an assistant professor in 2009. He received the Ontario Government of Research and Innovation's Early Researcher Award in 2010, and was promoted to associate professor in 2014. He received the Ontario Government of Research and Innovation's Early Researcher Award in 2010.
Plans call for recording the seminar for later posting on UCTV.
Coordinating the seminars is professor Steve Nadler. For a list of the speakers, see this page.
ScienceDaily reported on the research in its Oct. 28th edition.
The UC Davis Department of Entomology and Nematology team included Brian Johnson and Johnson lab researchers W. Cameron Jasper and Joey Atallah; and molecular geneticist Joanna Chiu. Other co-authors were Timothy Linksvayer of the University of Pennsylvania, Philadelphia, and Daniel Friedman, then a UC Davis undergraduate student in the Artyom Kopp lab.
“Whether coding or regulatory sequence change is more important to the evolution of phenotypic novelty is one of biology's major unresolved questions. The field of evo-devo has shown that in early development changes to regulatory regions are the dominant mode of genetic change, but whether this extends to the evolution of novel phenotypes in the adult organism is unclear. Here we conduct ten RNA-Seq experiments across both novel and conserved tissues in the honey bee to determine to what extent post-developmental novelty is based on changes to the coding regions of genes. We make several discoveries. First, we show that with respect to novel physiological functions in the adult animal, positively selected tissue-specific genes of high expression underlie novelty by conferring specialized cellular functions. Such genes are often, but not always taxonomically restricted genes (TRGs). We further show that positively selected genes, whether TRGs or conserved genes, are the least connected genes within gene expression networks. Overall, this work suggests that the evo-devo paradigm is limited, and that the evolution of novelty, post-development, follows additional rules. Specifically, evo-devo stresses that high network connectedness (repeated use of the same gene in many contexts) constrains coding sequence change as it would lead to negative pleiotropic effects. Here we show that in the adult animal, the converse is true: genes with low network connectedness (TRGs and tissue-specific conserved genes) underlie novel phenotypes by rapidly changing coding sequence to perform new specialized functions.”
Read research paper, “Large Scale Coding Sequence Change Underlies the Evolution of Post-Developmental Novelty in Honey Bees,” Molecular Biology and Evolution
Read "Bee's knees for identifying genetic triggers of novel adult traits," ScienceDaily news story
The honey bee garden owned and maintained by the UC Davis Department of Entomology and Nematology has received a $15,000 donation from the California State Society of the Daughters of the American Revolution.
State Regent Debra Jamison of Fresno, as part of her two-year fundraising project to support the troubled bee population, donated the funds to enhance the bee environment in the Häagen-Dazs Honey Bee Haven, a half-acre bee friendly garden located next to the Harry H. Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road.
Jamison, the 2012-2014 state regent, presented the check March 28 at a “lunch-with-the-bees” celebration organized by the UC Davis College of Agricultural and Environmental Sciences. Some 125 DAR members, some from as far away as Chico and San Diego, dined beneath a canopy of olive trees bordering the road.
“We appreciate this more than we can say,” said Ed Lewis, professor and vice chair of the department--and whose mother belongs to DAR.
This was DAR's second check presentation in two years to the UC Davis Department of Entomology and Nematology. In 2013, Jamison presented a check for $30,000 for bee research to assistant professor Brian Johnson.
On behalf of the department, haven manager Christine Casey accepted the $15,000 check from Jamison and Karen Montgomery of Modesto, the state regent's project chair. Casey announced that some of the funds have already been used to purchase two benches, and other projects will include a shade structure in the Growers Grove section and more bee habitat.
Jamison adopted the motto, “Bees are at the heart of our existence” and vowed to support honey bee research and enhance honey bee environments to help the beleaguered bees.
Honey bees prefaced the American Revolutionary War (1765-1783) by 143 years. European colonists brought the honey bee to Jamestown colony, Virginia, in 1622. Descendants of the American Revolutionary War formed DAR in 1890.
“When the state regent's project was conceived, I never imagined that honey bees would be in the serious state they are in,” Jamison told the luncheon crowd. “I could not have imagined that this amazing insect would make the cover of Time magazine, or that the California DAR would be involved in trying to do something to help the most vital insect in the animal kingdom.”
“Our 114 chapters and 15 districts have worked diligently to educate members, children, and the public about the plight of bees,” Jamison said. “This outreach has been truly outstanding. Add to that the phenomenal fundraising efforts. I truly thought that when I brought this project before the members that they might think, ‘Eeeeeuuuu, creepy insect, and weird state regent.'
Jamison presented certificates of appreciation to Extension apiculturist Eric Mussen and communication specialist Kathy Keatley Garvey of the UC Davis Department of Entomology and Nematology for their work in helping DAR with the two-year project.
“Kathy is the first live body I talked to about a possible project at UC Davis,” Jamison said. “She was immediately excited and hooked me up with the resident researcher here at the time. Our members know that Kathy is an accomplished micro-photographer, and they have seen many of Kathy's photos because she has been so open to sharing them with our organization. We also thank her for publicizing the first phase of this project. Our members were so excited to read all about it on the internet!”
Next, she paid tribute to Extension apiculturist Eric Mussen, a member of the faculty since 1976. “Dr. Mussen, there is no way we could have put this project together without you and all of the information you provided,” she told him. “Your willingness to meet with me, and to give a tour of the lab and Honey Bee Haven was so appreciated and so kind of you. Thank you for answering all of my questions and emails over the last two years.”
“A little bee at the Central Valley Beekeepers Association--of which I am now a member-- told me you would be retiring this summer. My best wishes for a happy retirement and more personal time to spend with your bees!”
"Bee Patriotic” rally towels decorated each table. Last year Jamison's rally towels were lettered with “Bee-lieve in the Power of DAR."
All those attending the March 28th luncheon received a “I Beelong to DAR” recyclable grocery bag.
The crowd toured the haven, which was installed in the fall of 2009, and ended the day with bee presentations in the Laidlaw facility conference room.
Mussen talked about the life cycle of bees and the issues bees face: malnutrition, pesticides, pests, parasites, diseases and stress. Malnutrition, Mussen said, is a bigger problem now than colony collapse disorder (CCD), a mysterious malady characterized by adult bees abandoning the hive. An active colony of honey bees requires an acre-equivalent of mixed blooms, daily, to meet their nutritional needs.
Mussen also warned that simply because certain pesticides are labeled for use in organic gardening does not mean that they are less dangerous for non-target insects, particularly pollinators. Also, insecticides that are watered into the soil and move from the roots, systemically throughout the plants, are secreted in the nectar and pollens when the treated plants bloom.
Johnson thanked DAR for the generous donation of $30,000 that he received last year. He said the financial support will cover a two-year period of graduate student research. His graduate student, Gerard Smith, researches the effect of pesticide exposure in the field on honey bee foraging behavior, and graduate student Cameron Jasper studies the genetic basis of division of labor in honey bees.