C3 Seminar: Dr Anusuya Willis
Strain variation in the toxic harmful algae Raphidiopsis raciborskii (Cylindropsermopsis raciborskii)
Cyanobacteria form harmful algal blooms and are highly adapted to a range of habitats, in part due to their phenotype plasticity. This plasticity is partially the result of co-existence of multiple strains within a single population. The toxic cyanobacterium Raphidiopsis raciborskii (basionym Cylindrospermopsis raciborskii) has remarkable phenotypic plasticity, strain variation and environmental adaptation resulting in an expansion of its global range.
Understanding how strain variation arises and the magnitude of variation between strains is needed to improved prediction and management of harmful blooms. Strains isolated from a single population were initially revealed to exhibit a range of different growth rates and toxin cell quotas under the same conditions. Strains exhibited equally variable genomes and transcriptomes which themselves were not sufficient to explain one another nor the variability within physiological responses. Whilst we observed a relatively large core genome and the transcriptome analysis indicated some common responses to nutrient stress, demonstrating a broad similarity between strains, the transcriptome analysis also showed strains used different genetic pathways to arrive at similar physiological responses.
The results indicate that the physiological variation between strains is a result of a complicated mix of genome and transcriptome-level variation, which may lead to fluctuating strain dominance in natural systems and an adaptive population. An understanding of strain variation is needed to optimise strain choice for laboratory studies, for comparison to field responses, and data inputs for models. In conclusion strains vary in their genomes, transcriptomes and physiology, therefore it is necessary to characterise multiple strains to be able to understand population responses to environmental variables.
Light refreshments provided after talk - All are welcome! If you have any question regarding this event, please contact Dr Bernhard Tschitschko: bernhard.tschitschko@uts.edu.au
Dr Anusuya Willis
Anusuya Willis is an algal molecular and cell biologist, her research interests are in understanding phytoplankton diversity, adaptation and population dynamics. In particular she is interested in how genome variation and differential gene expression in response to environmental stimuli leads to population changes, variable cell physiology and adaptation.
Anusuya obtained her PhD jointly from the University of Melbourne and the Université de Paris XI, with research on the biochemistry and cell-adhesion of the diatom Phaeodactylum tricornutum, using a combination of algal physiology and molecular biology techniques. Anusuya then moved to a post-doctoral position in the Department of Biochemistry, at the Georgia Institute of Technology, under the supervision of Dr. Nils Kroger, working on the development of a diatom for a biofuels feedstock.
From 2012 to 2017, Anusuya was a Research Fellow in Prof. Michele Burford’s group at the Australian Rivers Institute, Griffith University, where she investigated the variation in genotypes and phenotypes of toxic cyanobacteria isolates. Anusuya is currently a research scientist in the Australian National Algae Culture Collection (ANACC), CSIRO, Hobart, Tasmania, investigating algae ecology, cell biology and commercial applications.
