Two cubozoan jellyfish species endanger both locals and tourists visiting the beaches of northern Australia: the sea wasp Chironex fleckeri and the Irukandji jellyfish Carukia barnesi. Envenomation by both species results in severe pain, cardiac irregularities, and potentially death. Despite their medical importance, efficient antivenoms against these jellyfish have not been developed. The lack of effective antivenom is due to the instability of the venom toxins, especially when exposed to heat. Challenges in obtaining venom from these jellyfish has made it exceedingly difficult to identify the key toxins responsible for the envenomation syndromes and determine their molecular mechanisms of action.
We are utilising a novel multidisciplinary approach to characterise the molecular mechanisms underlying the human envenomation syndromes induced by these jellyfish These methods include genomics, proteotranscriptomics, assays of calcium cycling in human cardiomyocytes, and live imaging of zebrafish embryo hearts injected with jellyfish venom and toxins. We found that box jellyfish venom has an immediate impact on human cardiomyocytes and zebrafish hearts, whereas Irukandji venom only affects the heart/cardiomyocytes at high concentrations, suggesting that the heart is not the primary target of the venom. Identification of key toxins will be executed through the development of a venom proteome and assembly of a genome to understand the evolutionary importance of the toxins within Cubozoa. It is hoped that this research will aid in the development of life-saving treatments for box jellyfish envenomations.