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Richard M. Clark

Professor of Biological Sciences

Genetics, Gene Expression, Plant-Herbivore Interactions, Diapause, Carotenoids

Richard Clark


Molecular Biology Program


B.A. Kenyon College

Ph.D. Stanford University



Genetic variation is ubiquitous in plant and animal populations. Such variation underlies diverse morphological and life history traits, susceptibility to a broad spectrum of diseases, responses to other biotic challenges, as well as variation in the face of changes in the abiotic environment. Our group seeks a molecular-genetic understanding of the causes and consequences of such variation. Currently, a central focus of the laboratory is to understand the genetic, molecular, and biochemical bases of interactions between plants and the herbivores that graze on them. In particular, we are examining the basis of plant responses to herbivory by spider mites, an ecologically and agriculturally important group of arthropod herbivores for which comparatively little is known compared to insects. Apart from plant-herbivore studies, we are also interested in various aspects of plant and spider mite (and more generally arthropod) biology. For spider mites, this includes understanding how mite populations and genomes have responded to recent selection imposed by human agricultural practices. Another focus of the laboratory has been to elucidate the genetic architecture of variation in spider mite diapause (a physiological state needed for overwintering), as well as the biosynthesis, metabolism, and transport of carotenoids that are important for diapause in this group of globally invasive plant pests.

To address our questions, the laboratory uses molecular biology approaches, quantitative genetics, high-throughput genomic methods like genome sequencing and transcriptional profiling, and diverse bioinformatic approaches.

References (Selected Publications)

  1. Bryon, A., Kurlovs, A. H., Dermauw, W., Greenhalgh, R., Riga, M., Grbic, M., Tirry, L., Osakabe, M., Vontas, J., Clark, R. M., and Van Leeuwen, T. 2017. Disruption of a horizontally transferred phytoene desaturase abolishes carotenoid accumulation and diapause in Tetranychus urticae. PNAS 114(29):E5871-E5880. (PMCID: PMC5530703)
  2. Bryon, A., Kurlovs, A. H., Van Leeuwen, T., and Clark, R. M. 2017. A molecular-genetic understanding of diapause in spider mites: current knowledge and future directions. Physiological Entomology; advanced online version, doi: 10.1111/phen.12201.
  3. Rabanal, F.A., Mandáková, T., Soto-Jiménez, L. M., Greenhalgh, R., Parrott, D.L., Lutzmayer, S., Steffen, J. G., Nizhynska, V., Mott, R., Lysak, M. A., Clark, R. M., and Nordborg, M. 2017. Epistatic and allelic interactions control expression of ribosomal RNA gene clusters in Arabidopsis thaliana. Genome Biol. 18(1):75. (PMCID: PMC5414317)
  4. Imprialou, M., Kahles, A., Steffen, J. G., Osborne, E. J., Gan, X., Lempe, J., Bhomra, A., Belfield, E., Visscher, A., Greenhalgh, R., Harberd, N. P., Goram, R., Hein, J., Robert-Seilaniantz, A., Jones, J., Stegle, O., Kover, P., Tsiantis, M., Nordborg, M., Rätsch, G., Clark, R. M., and Mott R. 2017. Genomic Rearrangements in Arabidopsis Considered as Quantitative Traits. Genetics 205(4):1425-1441. (PMCID: PMC5378104)
  5. Ngoc, P. C., Greenhalgh, R., Dermauw, W., Rombauts, S., Bajda, S., Zhurov, V., Grbić, M., Van de Peer, Y., Van Leeuwen, T., Rouzé, P., and Clark, R. M. 2016. Complex Evolutionary Dynamics of Massively Expanded Chemosensory Receptor Families in an Extreme Generalist Chelicerate Herbivore. Genome Biology & Evolution 8(11):3323-3339. (PMCID: PMC5203786)
  6. Jonckheere, W., Dermauw, W., Zhurov, V., Wybouw, N., Van den Bulcke, J., Villarroel, C. A., Greenhalgh, R., Grbić, M., Schuurink, R. C., Tirry, L., Baggerman, G., Clark, R. M., Kant, M. R., Vanholme, B., Menschaert, G., and Van Leeuwen, T. 2016. The Salivary Protein Repertoire of the Polyphagous Spider Mite Tetranychus urticae: A Quest for Effectors. Molecular & Cellular Proteomics 15:3594-3613. (PMCID: PMC5141274)
  7. Meng, D., Dubin, M., Zhang, P., Osborne, E. J., Stegle, O., Clark, R. M., and Nordborg, M. 2016. Limited Contribution of DNA Methylation Variation to Expression Regulation in Arabidopsis thaliana. PLoS Genetics 12:e1006141. (PMCID: PMC4939946)
  8. Bajda, S., Dermauw, W., Greenhalgh, R., Nauen, R., Tirry, L., Clark, R. M., and Van Leeuwen T. 2015. Transcriptome profiling of a spirodiclofen susceptible and resistant strain of the European red mite Panonychus ulmi using strand-specific RNA-seq. BMC Genomics 16:974. (PMCID: PMC4652392)
Last Updated: 7/2/23