Research Interests - Stressed Out Science
How do evolutionary innovations happen? How do traits evolve in response to stress, and how can traits cause stress? I am intrigued by organisms that appear to transit 'negative trait space' to get to evolutionary innovations, whether that means co-opting stress machinery to survive extreme environments or choosing to withstand internal stresses to produce extreme structures. My research integrates several of the 'omics and physiology to investigate relationships between genotype, phenotype, and environmental conditions. I trend toward aquatic invertebrates as models.
Current Research Projects
Podocopid ostracods invaded freshwater multiple times, but the crazy ones then invaded vernal pool environments, ephemeral puddles that seasonally dry out. These little crustaceans independently evolved anhydrobiosis, sustaining life without water, multiple times. By studying the convergence of this ability, I will learn what's necessary for molecular stability against a background of extreme stress.
Some species of podocopid ostracods live in thermal hot springs, reaching temperatures of up to 55C! I'm working to develop these stressed-out guys into 'hot' new model organisms. So far, they're happy in peanut butter jars with complete neglect. Ask me about running thermal trials in thermocylers!
Chitons (Polyplacophora) are unusual among molluscs in dentition. They coat their teeth with iron in the form of magnetite, allowing them to scrape up algae from the rocky shore with minimal damage. But how exactly chitons manage to sequester so much iron, and deposit it so precisely, is unknown. I'm working to complete physiological and molecular analyses of this process to better understand how chitons wrangle this stress-laden, toxic metal.
Chitons evolved visual systems that are capable of spatial imaging, all without a brain with a visual processing center. How many times did vision evolve, and what can this tell us about the evolution of complex traits?
Other Recent Projects
Fall of 2020 I joined a research expedition to ANTARCTICA! Check out more about the cruise HERE!
I published the first genome of a chiton, Acanthopleura granulata, together with a discoveries about genetic mechanisms chitons may use to mitigate iron stress. (Read more HERE!)
Can telomeres provide information for shark ageing? We found that telomeres could provide an additional line of evidence. (Read more HERE!)
Also ask me about ongoing collaborations and upcoming publications on.....
Varney, R.M., Kingston, A.C.N., Kocot, K.M., Speiser, D.I. (in review) Chitons modulate pH and withstand oxidative stress to biomineralize iron-clad teeth.
Varney, R.M., Brenzinger, B., Malaquias, M.A.E. et al. (2021) Assessment of mitochondrial genomes for heterobranch gastropod phylogenetics. BMC Ecol Evo 21, 6 https://doi.org/10.1186/s12862-020-01728-y
Varney, R.M., Heinrich, K.K. A Garden, Not a Leaky Pipeline. (2021) The Teaching Professor 2021/2/15(1-3). https://www.teachingprofessor.com/topics/student-learning/a-garden-not-a-leaky-pipeline/
Nehmens MC, Varney RM, Janosik AM and Ebert DA (2021) An Exploratory Study of Telomere Length in the Deep-Sea Shark, Etmopterus granulosus. Front. Mar. Sci. 8:642872. 10.3389/fmars.2021.642872
Varney, R.M., Speiser, D.I., McDougall, C., Degnan, B.M., Kocot, K.M. (2020) The Iron-Responsive Genome of the Chiton Acanthopleura granulata, Genome Biology and Evolution, Volume 13, Issue 1, January 2021, evaa263, https://doi.org/10.1093/gbe/evaa263
Varney, R.M., Funch, P., Kocot, K.M., Sørensen, M.V. (2019). A new species of Echinoderes (Cyclorhagida: Echinoderidae) from the San Juan Islands, Washington State, USA, and insights into the kinorhynch transcrioptome. Zoologischer Anzeiger 282 (52-63). https://doi.org/10.1016/j.jcz.2019.06.003
Kocot, K. M., Wollesen, T., Varney, R. M., Schwartz, M. L., Steiner, G., & Wanninger, A. (2019). Complete mitochondrial genomes of two scaphopod molluscs. Mitochondrial DNA. Part B, Resources, 4(2), 3161–3162. https://doi.org/10.1080/23802359.2019.1666689
Varney, R.M., Pomory, C.M. & Janosik, A.M. Telomere elongation and telomerase expression in regenerating arms of the starfish Luidia clathrata (Asteroidea: Echinodermata). Mar Biol 164, 195 (2017). https://doi.org/10.1007/s00227-017-3230-x