Team:Georgia State/Description
Our Inspiration
The inspiration behind our project was the Netflix documentary Chasing Coral. From this documentary we learned about the extent of the devastation to coral reefs caused by bleaching. Many of the scientists seen in the film expressed despair over the seeming inevitability of the destruction. While current efforts to protect reefs have focused on enacting marine protected areas to prevent commercial fishing and industrial activities from harming the reefs, these efforts cannot stop the environmental effects of climate change on ocean waters. In the absence of a realistic proposal to halt global warming by eliminating fossil fuel consumption, marine heatwaves will become more frequent and even more severe ( Nature Communications volume 9, Article number: 1324 (2018), https://www.nature.com/articles/s41467-018-03732-9) leading to a corresponding increase in coral bleaching and reef loss. About half of the Great Barrier Reef died after the heat wave of 2016/2017.https://www.newscientist.com/article/2198318-the-great-barrier-reef-is-losing-its-ability-to-recover- from-bleaching/.And according to the UN Special Report on Global Warming, all global reefs around the world are expected to completely die off if global temperatures increase by another 2 degrees Celsius (https://www.ipcc.ch/2018/10/08/summary-for-policymakers-of-ipcc-special-report-on-global- warming-of-1-5c-approved-by-governments/).
The Problem
Coral bleaching, the loss of algal symbionts necessary for the survival of cnidarian reef organisms, is a disastrous environmental issue with global consequences. No single factor has been established as the cause of this catastrophe, but there are a multitude of suspects including increased greenhouse gas emissions and rising seawater temperatures[1].
The Solution
Although there is no absolute certainty about the cause of coral bleaching, increasing water temperatures have been directly correlated with subsequent bleaching events. And coral bleaching can be stimulated in aquarium corals by raising the water temperatures. There are some strains of corals and their symbiotic algae that prove somewhat more resistant to bleaching than others. So we proposed to identify those characteristics that might improve the ability to withstand bleaching and use a synthetic biology approach to modify the algae and restore them to corals.
The Plan
We are establishing both culturing and transformation protocols for these microalgae symbionts. We began by optimizing culturing techniques for Symbiodinium microadriaticum, Oxyrrhis marina (our model organism), and Dunaliella tertiolecta (the food source for O. marina).
To identify optimal algal growth conditions, we tested various factors such as growth media, light intensity, and temperature. We designed a codon optimized red fluorescent protein part that was cloned into a dinoflagellate-optimized expression plasmid (DinoIII)[2] for transformation into our model organism as a proof of concept. In parallel, we are also attempting to replicate the only known successful transformation of Symbiodinium using an Agrobacterium tumefacien co-culture carrying a binary vector, pCB302-GFP-MBD[3], and designing/executing various electroporation protocols. A genomic analysis of clade D Symbiodinium, a clade associated with higher resistance to bleaching but diminished coral growth, will identify target genes related to bleaching resistance for transformation into the growth-favorable clade C of Symbiodinium. The corals will then uptake the modified host algae, increasing their resistance to bleaching.
