- Author: Kathy Keatley Garvey
It did: their research revealed how TSWV (family Tospoviridae, order Bunyavirales) packages its RNA genome, a crucial step in virus infection.
Their newly published research, “The Genome of a Bunyavirus Cannot be Defined at the Level of the Viral Particle But Only at the Scale of the Viral Population,” appears in the current edition of the Proceedings of the National Academy of Sciences (PNAS).
The 18-member research team included scientists primarily from the French National Research Institute for Agriculture, Food and Environment (INRAE) at the Campus International de Baillarguet, Montpellier; Department of Entomology, University of Wisconsin; and the Department of Entomology and Nematology, University of California, Davis.
“Our work showed the genome of TSWV can only be defined at the population level, pointing at emerging properties when viral particles infect plants in groups,” said a key author Stéphane Blanc, research director of INRAE's Biology and Genetics of Plant-Pathogen Interactions. “As most virions contain an incomplete genome, TSWV is a multi-component viral system, where co-infection and complementation are key in the life cycle. These findings open a myriad of possibly distinct properties depending on the genetic composition of the group of virions co-infecting a cell.”
“The most challenging part of this work was to create a protocol reliably quantifying the two polarities of each segment,” said lead author Michel Yvon of INRAE. “The next important advance will be to demonstrate that co-infection of cells by a group of particles is key to the spread of infection.”
Ullman, an international authority on orthotospoviruses and one of the four main authors, took a sabbatical to work on the project. “My interest was in understanding how TSWV packaged its RNA genome,” she said. “While this sounds like a simple goal, it is quite complex because TSWV has negative sense and ambisense viral strands and many research tools common to studying other viruses, such as infectious clones were not available.”
“It was a delight to work with the fantastic team of scientists that Stéphane assembled, all very talented with skills in virology, cryoelectron microscopy and nanopore PCR,” Ullman commented. “I cannot imagine a more talented and diverse group of people to conduct this difficult work. I learned a great deal about virus purification from Michel Yvon, whose leadership, skills in virology, and patient teaching really moved our project forward."
German, professor emeritus and former chair of both the Departments of Plant Pathology and Entomology at the University of Wisconsin, died Aug. 27, 2023 at age 82.
“I am indebted to my husband, Jean-Marc Leininger who frequently drove me to the laboratory in Avignon where I was able to rear thousands of virus-infected plants and to store TSWV isolate,” Ullman added. “Jean-Marc not only transported me and my virus specimens, but also learned to mechanically inoculate plants and helped with every inoculation and virus harvest.”
UC Davis postdoctoral scholar Sulley Ben-Mahmoud of the Ullman lab was among the co-authors.
Funding was provided by grants from Montpellier University of Excellence (MUSE); Floriculture and Nursery Research Initiative, U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS); and the Fulbright Scholar Program. The authors also acknowledged support from
- Santé des Plantes et Environnementor Plant Health and Environment (SPE)
- Centre National de la Recherche Scientifique (CNRS)
- Institute of Research for Development (IRD)
- Institut national de la santé et de la recherche médicale (INSERM)
- Centre for International Cooperation in Agronomic Research for Development (CIRAD)
- Plant Health Institute of Montpelier (PHIM)
Ullman noted the importance of the research in her Fulbright application: “Sustainable management of insect-transmitted pathogens is a key concern for food production in France and the United States. Both countries grow many of the same crops and growers face similar challenges from insect-transmitted plant viruses. Current management strategies rely heavily on pesticides that may cause significant health and environmental concerns, including damage to bees and other pollinators, as shown with neonicotinoid pesticides. Clearly, better knowledge about these insect-transmitted viral systems…has potential to reduce pesticide use by providing novel and innovative technologies to manage orthotospoviruses and thrips in France and the United States.”
Ullman, a former chair of the Department of Entomology and a former associate dean of the UC Davis College of Agricultural and Environmental Sciences, anticipates strong research relationships between UC Davis and Montpellier that will lead to grant applications for international research and scholarly exchange opportunities for scientists, students, and post-doctoral scholars.
Significance
In their significance statement, the authors wrote: “Bunyaviruses infect animals, plants, fungi, and protists. Despite their importance, fundamental aspects of their biology as basic as the definition of their genome remain elusive. The viral genome consists of several negative or ambisense RNA segments, and virions often miss segments and/or package complementary strands. We formally quantify this heterogeneity on the species Tomato spotted wilt orthotospovirus. Within individual virus particles, the number, the identity, and the polarity of the segments are widely variable. In contrast, we show that a stable genetic composition is an emerging property of the viral population, each of the RNA segments/polarities accumulating reproducibly at a specific frequency. This resembles the genome formula of multipartite viruses, suggesting that bunyaviruses may also function as multicomponent viral systems.”
Their abstract: “Bunyaviruses are enveloped negative or ambisense single-stranded RNA viruses with a genome divided into several segments. The canonical view depicts each viral particle packaging one copy of each genomic segment in one polarity named the viral strand. Several opposing observations revealed nonequal ratios of the segments, uneven number of segments per virion, and even packaging of viral complementary strands. Unfortunately, these observations result from studies often addressing other questions, on distinct viral species, and not using accurate quantitative methods. Hence, what RNA segments and strands are packaged as the genome of any bunyavirus remains largely ambiguous. We addressed this issue by first investigating the virion size distribution and RNA content in populations of the tomato spotted wilt virus (TSWV) using microscopy and tomography. These revealed heterogeneity in viral particle volume and amount of RNA content, with a surprising lack of correlation between the two. Then, the ratios of all genomic segments and strands were established using RNA sequencing and qRT-PCR. Within virions, both plus and minus strands (but no mRNA) are packaged for each of the three L, M, and S segments, in reproducible nonequimolar proportions determined by those in total cell extracts. These results show that virions differ in their genomic content but together build up a highly reproducible genetic composition of the viral population. This resembles the genome formula described for multipartite viruses, with which some species of the order Bunyavirales may share some aspects of the way of life, particularly emerging properties at a supravirion scale.”
- Author: Kathy Keatley Garvey
Nieh will present his seminar at 4:10 p.m., Monday, Dec. 4 in Room 122 of Briggs Hall and also on Zoom. The Zoom link:
https://ucdavis.zoom.us/j/95882849672
"Karl von Frisch referred to the waggle dance as the 'magic well' for the insights that it provides not only on honey bees, but on the general cognitive complexity that social insects are capable of," Nieh writes in his abstract. "New research demonstrates that the neurotransmitter, dopamine, the 'pleasure molecule' plays a similar hedonic role in honey bees as it does in many vertebrates, regulating the perception of danger and the anticipation of food rewards as revealed in the excitatory waggle dance and the associated, inhibitory stop signal. I will also discuss new data showing that the honey bee waggle dance is partially learned and has elements that may be culturally transmitted. Together, these findings, demonstrate that the waggle dance can teach us a great deal about shared cognitive mechanisms and the importance of social learning across taxa."
In an article titled "Unlocking Secrets of the Honeybee Dance Language--Bees Learn and Culturally Transmit Their Communication Skills," and published March 9, 2023 in The Conversation, Nieh described the waggle dance as "one of the most complicated examples of nonhuman communication. They can tell each other were to find resources such as food, water, or nest sites with a physical 'waggle dance.' this dance conveys the This dance conveys the direction, distance and quality of a resource to the bee's nestmates."
Nieh related exactly how the bees perform the waggle dance. "Essentially, the dancer points recruits in the correct direction and tells them how far to go by repeatedly circling around in a figure eight pattern centered around a waggle run, in which the bee waggles its abdomen as it moves forward. Dancers are pursued by potential recruits, bees that closely follow the dancer, to learn where to go to find the communicated resource."
"Longer waggle runs communicate greater distances," Nieh wrote, "and the waggle angle communicates direction. For higher-quality resources such as sweeter nectar, dancers repeat the waggle run more times and race back faster after each waggle run."
Nieh noted that "The Greek historian Herodotus reported over 2,000 years ago on a misguided forbidden experiment in which two children were prevented from hearing human speech so that a king could discover the true, unlearned language of human beings.
"Scientists now know that human language requires social learning and interaction with other people, a property shared with multiple animal languages. But why should humans and other animals need to learn a language instead of being born with this knowledge, like many other animal species?"
Nieh went on to point out that "This question fascinates me and my colleagues and is the basis for our recent paper published in the journal Science. As a biologist, I have spent decades studying honeybee communication and how it may have evolved."
Nieh received his bachelor's degree from Harvard University in 1991 and his doctorate from Cornell University in 1997. He completed a postdoctoral fellowship funded by NSF-NAT0 (National Science Foundation, North Atlantic Treaty Organization) at the University of Würzburg, Germany. He served as a Harvard Junior Fellow from 1998-2000
Seminar coordinator is Brian Johnson, associate professor, UC Davis Department of Entomology and Nematology. For Zoom technical issues, he may be reached at brnjohnson@ucdavis.edu. The list of seminars is posted here.
Resources:
- Social Signal Learning of the Waggle Dance in Honey Bees, March 9, 2023, Science
- Bees Can Teach Their Young to Dance, March 9, 2023, Washington Post
- The Waggle Dance, PBS documentary on YouTube
- Author: Kathy Keatley Garvey
Dag will present his seminar at 4:10 p.m. in Room 122 of Briggs Hall. It also will be on Zoom: the Zoom link:
https://ucdavis.zoom.us/j/
"Tree crops belonging to the Rosaceae, such as almond, pear, apple, and sweet cherry, depend on cross-pollination by insects to set fruit," Dag says in his abstract. "The primary pollinator of the crops is the honey bee (Apis mellifera). However, due to harsh climatic conditions during flowering, limited movement of bees between cultivars, low preference of the bees for flowers of the target crop, and limited overlap in flowering between the cultivars, pollination is a primary factor limiting yield. Our group has tested multiple approaches to mitigate this problem: Using 'Pollen dispensers,' sequential introduction of beehives to the orchards, selection of honeybee strains with higher preference for the target crop, introduction of bumblebee (Bombus terrestris) colonies and phosphorous fertilization to increase nectar secretion and improve crop-flower attractiveness. I will summarize the effects of those methods on fruit set and yield in apples, almonds, and pears."
A native of Moshav Lachish, Israel, Dag received his bachelor's degree (1990) and master's degree (1992) in life sciences at the Faculty of Life Sciences, Tel Aviv University. His master's thesis: "Improving the Honey Bee Efficiency of Melon Pollination in Greenhouses." He obtained his doctorate in agriculture at the Horticulture, Faculty of Agriculture at Hebrew University of Jerusalem. His thesis: "Pollenizers, Pollinators and Pollination in Mango." He held postdoctoral positions at both Tel Aviv University and the Hebrew University of Jerusalem.
Dag's research interests include fruit tree physiology, olive biology and cultivation, reproductive biology of fruit trees, crop pollination, pomology in semi-arid conditions and "developing guava as an export crop."
He served as an Extension specialist in beekeeping from 1991 to 2003 for the Israeli Ministry of Agriculture.
Seminar coordinator is Brian Johnson, associate professor, UC Davis Department of Entomology and Nematology. For Zoom technical issues, he may be reached at brnjohnson@ucdavis.edu. The list of seminars is posted here.
- Author: Kathy Keatley Garvey
There's plenty to love and purchase in the Bohart Museum of Entomology gift shop and on the UC Davis Entomology Graduate Student Association (EGSA) website.
EGSA members design insect and arachnid-themed T-shirts that climb, crawl, jump, roll, flutter, buzz, fly or otherwise position themselves on EGSA T-shirts. They can be viewed and ordered online at https://mkt.com/UCDavisEntGrad/.
EGSA president Mia Lippey, a doctoral student in the laboratories of UC Davis distinguished professor Jay Rosenheim and assistant professor Emily Meineke, says that currently, the designs offered are:
- The Beetles (in black or red)
- Entomo Gothic (a play on the American Gothic, in grey)
- Whip Scorpion (in lavender and black)
- Bee-Haw (in black)
- They See Me Rollin' (dung beetles rolling a poop, in heather blue)
- Et in Terra (dark green)
- Entomophagy (in blue and green)
At the Bohart Museum, located in Room 1124 of the Academic Surge Building, 455 Crocker Lane, the gift shop is stocked with everything from T-shirts, hooded sweatshirts, jewelry, books, posters, stickers, and note cards to lathe pens and insect-collecting equipment. See more at https://bohart.ucdavis.edu/line-gift-shop. Items may be purchased only in the gift shop, not online.
New items include tardigrade, bumble bee and monarch pens, monarch and stick insect stickers from a local artist, and a new mosquito stuffed toys or plushies, including a giant one that comes with viruses, said Brennen Dyer, the Bohart Museum's (specimen) collection manager.
Newest t-shirts are designed with tardigrades, also known as water bears. The Bohart Museum's tardigrade current collection includes some 25,000 slide-mounted specimens, and a six-foot-long concrete sculpture by Solomon Bassoff of North San Juan, Calif., graces the entrance to the Academic Surge building.
The Bohart Museum, founded in 1946, is directed by UC Davis distinguished professor Lynn Kimsey. It houses a global collection of eight million insect specimens. In addition to its gift shop, it is also the home of a live petting zoo. The Bohart is closed on specific days during the holiday season. See hours on the website.
- Author: Kathy Keatley Garvey
One UC Davis doctoral alumnus and 10 current or former members of the UC Davis Department of Entomology and Nematology are listed as among the world's top two percent of entomologists in a database announced by Stanford University with data from Elsevier's “science-wide author databases of standardized citation indicators.”
A separate list, gleaned from the main document, names the world's top entomologists, totaling 708. UC Davis alumnus Murray Isman, who received his doctorate in 1981 from UC Davis, studying entomology and toxicology, is ranked No. 2. He is the dean emeritus of the University of British Columbia's Faculty of Land and Food Systems and emeritus professor of entomology and toxicology at UBC.
The highest UC Davis entomologist/faculty member on that list is No. 22-ranked UC Davis distinguished professor Walter Leal of the Department of Molecular and Cellular Biology, former professor and chair of the Department of Entomology (now Department of Entomology and Nematology).
Other UC Davis entomologists on the list, in the order of ranking, are:
- Jay Rosenheim, No. 68
- Harry Kaya, 206
- Fumio Matsumura (1934-2012), 208
- James R. Carey, 232
- Robbin Thorp (1933-2019) 321
- Christian Nansen, 452
- Lester Ehler (1946-2016) 593
- Robert E. Page Jr., 548
- Frank Zalom, 557
Elsevier. Elsevier, a global information analytics company that helps institutions and professionals progress science, advance healthcare and improve performance, published its "science-wide author databases of standardized citation indicators" on Oct. 4, 2023. The ranking of scientists is at https://elsevier.digitalcommonsdata.com/datasets/btchxktzyw. It is a publicly available database "of top-cited scientists that provides standardized information on citations, h-index, co-authorship adjusted hm-index, citations to papers in different authorship positions and a composite indicator (c-score). Separate data are shown for career-long and, separately, for single recent year impact. Metrics with and without self-citations and ratio of citations to citing papers are given. Scientists are classified into 22 scientific fields and 174 sub-fields according to the standard Science-Metrix classification. Field- and subfield-specific percentiles are also provided for all scientists with at least 5 papers. Career-long data are updated to end-of-2022 and single recent year data pertain to citations received during calendar year 2022. The selection is based on the top 100,000 scientists by c-score (with and without self-citations) or a percentile rank of 2% or above in the sub-field. This version (6) is based on the October 1, 2023 snapshot from Scopus, updated to end of citation year 2022. This work uses Scopus data provided by Elsevier through ICSR Lab (https://www.elsevier.com/icsr/icsrlab). Calculations were performed using all Scopus author profiles as of October 1, 2023. If an author is not on the list it is simply because the composite indicator value was not high enough to appear on the list. It does not mean that the author does not do good work."
Scientists from China filtered the list to spotlight only entomologists. The list is at https://wxredian.com/art?id=9f6eea221698e282/.