Title: Delving into the Genetic Code of Gambierdiscus – the Devil is in the Detail
Supervisor: Associate Professor Aaron Darling
Some species of the genus Gambierdiscus produce ciguatoxins (a type of neurotoxin), which is the causative agent of ciguatera fish poisoning. Ciguatera is a highly morbid and globally the most common non-bacterial seafood borne illness. The habitat range of Gambierdiscus is expanding due to climate change, yet monitoring tools for outbreaks are elusive and the characterization of which species produce these toxins is ongoing work.
This is in part due to the peculiar genetics of Gambierdiscus which have made inquiries into the species evolution as well as the evolution of the toxin producing enzymes far from straight forward. Species of Gambierdiscus possess very large genomes, ~35 Gbp, and, as with other dinoflagellates, possess unique genomic characteristics, e.g. highly repetitive and complex genome architecture, meaning that genomic sequencing remains infeasible.
My project aims to contribute to the haracterization of Gambierdiscus diversity in Australia, develop environmental molecular monitoring tools for Gambierdiscus species and investigate species evolution of the genus as well as common and novel genes expressed between species.
Chapter 1) The diversity of Gambierdiscus around Heron Island in the GBR;
Chapter 2) Developing molecular probes for G. lapillus and G. polynesiensis for
Chapter 3) Investigating the evolution of the gonyaulacales and assess the impact of
data and model selection of commonly employed phylogenetic methods; and
Chapter 4) The core- and pan-transcriptomes of .Gambierdiscus.
1. Murray, S. A., Ajani, P.; Kretzschmar, A. L. & Verma, A. (2017) Response to”
More surprises in the global greenhouse: Human health impacts form recent toxic
marine aerosol formulations, due to centennial alterations or world-wide coastal
food web”s. Mar. pol. Bulletin.
2. Kohli, G.; Haslauer, K.; Chowdhury, S.; Boulter, M.; Kretzschmar, A. L.; Har-
wood, T.; Laczka, O. & Murray, S. (2017) Qualitative and Quantitative Assessment
of the Presence of Ciguatoxin, P-CTX-1B, in Spanish Mackerel (Scomberomorus
commerson) from waters in NSW (Australia). Toxicol. Reports 4 328-334.
3. Kretzschmar, A. L.; Verma, A.; Harwood, T.; Hoppenrath, M. & Murray, S.
(2017) Characterisation of Gambierdiscus lapillus sp. nov. (Gonyaulacales, Dino-
phyceae): A new toxic dinoflagellate from the Great Barrier Reef (Australia). J
Phycol 53(2): 283-297. Awarded cover image.
4. Kretzschmar, A. L. & Manefield, M. (2015) The role of lipids in activated sludge
floc formation. AIMS Environ Sci 2: 122-133.