- Author: Kathy Keatley Garvey
He will speak in person at 4:10 p.m. in 122 Briggs Hall. For those unable to attend, his lecture also will be on Zoom; link to https://ucdavis.zoom.us/j/99515291076.
"Plants interact with incredibly diverse groups of animals including plant-feeding insects and nematodes as well as their natural enemies," Groen says in this abstract. "These interactions are influenced by toxic defensive chemicals that plants make. In my talk, I will focus on how plants evolved variation in production of these defensive chemicals and how animal parasites in turn evolved mechanisms enabling them to handle such toxins."
He recently authored an article in the journal Current Biology on "Convergent Evolution of Cardiac-Glycoside Resistance in Predators and Parasites of Milkweed Herbivores."
From EurekaAlert: "Scientists now understand how certain animals can feed on picturesque, orange monarch butterflies, which are filled from head to abdomen with milkweed plant toxins. In high enough concentrations, milkweed can kill a horse, or a human. To be able to eat this plant, monarchs evolved a set of unusual cellular mutations. New UC Riverside research shows the animals that prey on monarchs also evolved these same mutations. A Current Biology journal article describes the research that revealed these mutations in four types of monarch predators — a bird, a mouse, a parasitic wasp, and a worm."
Groen, who joined the UC Riverside faculty in July 2021 following his postdoctoral research position (2014 to 2021) in the Noah Whiteman laboratory, Department of Ecology and Evolutionary Biology, University of Arizona, focuses his research on "understanding molecular mechanisms of adaptation in the context of species interactions and fluctuating environmental conditions."
A native of the Netherlands, he received his bachelor's degree and masters degree in biology from Wageningen University, Netherlands, and his doctorate in plant sciences from the University of Cambridge, UK.
Groen served as a visiting researcher from 2007 to 2008 in the Department of Multi-Trophic Interactions, Netherlands Institute of Ecology, and as a visiting researcher from 2008 to 2012 in the Department of Organismic and Evolutionary Biology, Harvard University.
"Growing up in The Netherlands, I became fascinated with plants and their responses to ever-changing environmental conditions while working as a 'ziekzoeker' in tulip fields outside of school hours," he writes in an author profile on the American Society of Plant Biologists website. The site featured him as the first author of “Evolutionary Systems Biology Reveals Patterns of Rice Adaptation to Drought-Prone Agro-Ecosystems," published Nov. 15, 2021 in the journal Plant Cell.
"A 'ziekzoeker' looks for diseased plants and I searched in particular for variegated white and red tulips--the ones you'd recognize from a golden-age Dutch still life painting," Groen related. "I learned how these tulips are infected with an aphid-transmitted virus and during my PhD in the group of John Carr at the University of Cambridge, I would further investigate the molecular mechanisms of how virus infections would change plant interactions with aphids and pollinators. I was gripped by the role that plant defensive chemicals play in shaping species interactions and I continued to study these as a postdoc with Noah Whiteman at the University of Arizona and the University of California, Berkeley.'
On the author page, he chronicled his previous work on the interactions between milkweeds and the monarch butterfly "and found out how the monarch evolved resistance to the cardenolide toxins that milkweeds make. While this work mostly revolved around a single gene of large effect, typically several or many genes are involved in organisms' evolutionary responses. As a Gordon and Betty Moore Foundation fellow in the group of Michael Purugganan at New York University, I learned about the latest developments in evolutionary genomics and systems biology while investigating patterns of natural selection on gene expression in rice populations that we grew under wet and dry field conditions with our collaborators at the International Rice Research Institute in The Philippines."
"The current paper (Plant Cell) is a culmination of this research," Groen related. "We found that under field drought rice plants do not just respond to changes in water availability, but also to concomitant changes in abundance of soil microbes that they interact with. As assistant professor in the Department of Nematology at the University of California, Riverside, I will continue to study rice and milkweed as well as plants from the nightshade family and look at the complex evolutionary tug-of-war between these plants and parasitic nematodes. Combining laboratory and field experiments, we will zoom in on the central role that plant chemicals play by using approaches from evolutionary and systems biology like the ones we describe in our paper."
Nematologist Shahid Siddique, assistant professor in the Department of Entomology and Nematology, coordinates the winter quarter seminars. He may be reached at ssiddique@ucdavis.edu for any technical issues involving the Zoom connection.
/span>- Author: Kathy Keatley Garvey
His seminar is from 12:10 to 1 p.m. in 122 Briggs Hall.
“Insects and other arthropods are infected with maternally transmitted endosymbionts,” Jaenike says in his abstract. “ Some of these symbionts spread and persist by manipulating host reproduction in various ways. However, many have no such effects, and the means by which they are retained within species is unknown. We recently found that Drosophila neotestacea carries endosymbiotic Spiroplasma bacteria, which render female flies resistant to the sterilizing effects of nematode parasitism."
"The prevalence of Spiroplasma infection in D. neotestacea increased rapidly in eastern North America in recent decades, and it is now spreading rapidly from east to west across North American. Coincident with the increase in Spiroplasma infection has been a dramatic decline in the prevalence of nematode parasitism, due, we believe, to the much lower reproductive output of nematodes that parasitize Spiroplasma-infected flies. We microinjected Spiroplasma into several other Drosophila species; the infections quickly stabilized with high levels of maternal transmission. In one species, D. putrida, Spiroplasma rendered flies resistant to the sterilizing effects of nematode parasitism. Finally, we microinjected various strains Spiroplasma obtained from other Drosophila species into D. neotestacea and found that only the strain native to D. neotestacea confers any resistance to nematode parasites.
Jaenike, a fellow of the American Association for the Advancement of Science (AAAA), focuses his research on host-parasite interactions, heritable endosymbionts, and ecology of Drosophila.
He received his bachelor of arts degree in biology from Amherst College in 1971 and his doctorate in biology from Princeton University in 1975. His faculty positions include State University of New York (SUNY), 1979-1983; University of Rochester, 1983-1999; University of Arizona, 1999-2001; and University of Rochester, 2001-present.
A few of his publications:
Early career
Jaenike, J. 1978. On optimal oviposition behavior in phytophagous insects. Theoretical Population Biology 14:350-356.
Jaenike, J. 1978. An hypothesis to account for the maintenance of sex within populations. Evolutionary Theory 3:191-194.
Mid-career
Jaenike, J. 1986. Genetic complexity of host selection behavior in Drosophila. Proceedings of the National Academy of Sciences. USA 83:2148-2151.
Jaenike, J. 1990. Host specialization in phytophagous insects. Annual Review of Ecology and Systematics, 21:243-273.
Jaenike, J. 1992. Mycophagous Drosophila and their nematode parasites. American Naturalist 139: 893-906.
Later in career
Dyer, K. A. and J. Jaenike. 2004. Evolutionarily stable infection by a male-killing endosymbiont in Drosophila innubila: molecular evidence from the host and parasite genomes. Genetics 168: 1443-1455.
Jaenike, J., K. A. Dyer, C. Cornish, and M. S. Minhas. 2006. Asymmetrical reinforcement and Wolbachia infection in Drosophila. PLoS Biology 4: 1852-1862.
Jaenike, J., R. L. Unckless, S. N. Cockburn, L. M. Boelio, and S. J. Perlman. 2010. Adaptation via symbiosis: recent spread of a defensive symbiont in Drosophila. Science 329: 212-215.
Plans call for video-recording the seminar for later posting on UCTV.