Electrophorus electricus, the strong voltage electric eel, occurs in rivers throughout South America. These fish are capable of generating strong electrical discharges of 600 volts or more, using specialized cells called electrocytes. This electrical power permits the eels to stun and kill both predators and prey. The long-term goal of this study is to create synthetic bio-batteries modeled after these electrocytes. By identifying the proteins used in nature to create, store and release an electrical potential, this project will lay the foundation for the first synthetic biological battery. This project will involve the sequencing of genomic DNA and electrocyte RNA to define the unique proteins (especially ion pumps and membrane channels and their regulators) of the electrocyte. These proteins will be purified and their electrical and regulatory properties will be studied in synthetic membranes and liposomes to define their unique and electrocyte-specific functional properties.
Broader Impacts. This project can define a framework for new ways to create and manipulate biologically-derived electrical energy, and could thus have substantial impacts in energy research and production. The investigator and the University of Wisconsin Biotechnology Center's outreach staff will use the electric eels and their electrocytes to help in educating and communicating to the public basic knowledge of how biological organisms create and use electrical energy. A team of undergraduates at the University of Wisconsin-Madison will develop a synthetic biology bio-energy project using genetic toolkits, including one from the electric eel, and will compete in the iGEM (International Genetically Engineered Machines) competition for undergraduate research.
This project involves a large interdisciplinary team of researchers focused on trying to discover the molecular mechanisms by which electric fish create and use electric power. Underlying this phenomenon is the electric organ, a tissue known to be derived from muscle, that converts chemical energy into raw electric power that is used by these unique fish to navigate, communicate and in a few cases, for predation and defense. The overall goal of this project is to use modern genomic sequencing and analysis methods to determine the structure of the proteins in the electric organ that uniquely allow it to generate this large amount of electrical power. For this purpose we sequenced the genomic DNA of the South American strong voltage electric eel, Electrophorus electricus, as well as the mRNA from expressed genes in eight tissues, including brain, spinal chord, skeletal muscle, heart muscle, two strong voltage electric organs and one weak electric organ. From this dataset we found ca. 200 genes that are only active in the electric organ, including the sodium channels and sodium pumps that are known to be responsible for generating the transcellular electric potentials that underlie the electric fish’s unique elecrogenic capabilities. Basically, the electrocyte that makes up the electric organ is derived from a muscle cell that has lost its contractility, and instead, has replaced it with electrogenesis. A major outcome from this work is the identification of candidate transcription factors and microRNA’s that are potential tools for use in synthetic biology, where we attempt to create electrocytes and electric organs in organisms that normally do not make them.
