The case for sequencing the genome of the electric eel Electrophorus electricus

Abstract

A substantial international community of biologists have proposed the electric eel Electrophorus electricus (Teleostei: Gymnotiformes) as an important candidate for genome sequencing. In this study, the authors outline the unique advantages that a genome sequencing project of this species would offer society for developing new ways of producing and storing electricity. Over tens of millions of years, electric fish have evolved an exceptional capacity to generate a weak (millivolt) electric field in the water near their body from specialized muscle-derived electric organs, and simultaneously, to sense changes in this field that occur when it interacts with foreign objects. This electric sense is used both to navigate and orient in murky tropical waters and to communicate with other members of the same species. Some species, such as the electric eel, have also evolved a strong voltage organ as a means of stunning prey. This organism, and a handful of others scattered worldwide, convert chemical energy from food directly into workable electric energy and could provide important clues on how this process could be manipulated for human benefit. Electric fishes have been used as models for the study of basic biological and behavioural mechanisms for more than 40 years by a large and growing research community. These fishes represent a rich source of experimental material in the areas of excitable membranes, neurochemistry, cellular differentiation, spinal cord regeneration, animal behaviour and the evolution of novel sensory and motor organs. Studies on electric fishes also have tremendous potential as a model for the study of developmental or disease processes, such as muscular dystrophy and spinal cord regeneration. Access to the genome sequence of E. electricus will provide society with a whole new set of molecular tools for understanding the biophysical control of electromotive molecules, excitable membranes and the cellular production of weak and strong electric fields. Understanding the regulation of ion channel genes will be central for efforts to induce the differentiation of electrogenic cells in other tissues and organisms and to control the intrinsic electric behaviours of these cells. Dense genomic sequence information of E. electricus will also help elucidate the genetic basis for the origin and adaptive diversification of a novel vertebrate tissue. The value of existing resources within the community of electric fish research will be greatly enhanced across a broad range of physiological and environmental sciences by having a draft genome sequence of the electric eel.

Unexpected species diversity in electric eels with a description of the strongest living bioelectricity generator

“…Assessment of further population and/or species diversity in Electrophorus will follow this study, based on the incorporation of additional specimens from targeted areas (including the upper Negro and Orinoco drainages). A comprehensive understanding of Electrophorus could also reveal a hidden variety of enzymatic or bioelectrogenic functions of interest to the broader scientific community 39 .…”

From Sequence to Spike to Spark: Evo-devo-neuroethology of Electric Communication in Mormyrid Fishes

“…A key resource for progress on this research agenda is the establishment of genomic and transcriptomic resources. A call for genomic sequencing in gymnotiform electric fi shes has been made (Albert et al, 2008). Here, we make the case for genomic sequencing in mormyrids.…”

Nano‐dielectrics in biosystems

“…Prey is not the only purpose of the discharge from electric fishes. The electric fish will generate a weak electric field around its body and maintain a certain weak current between the head and tail [4,58]. When a foreign body appears in its surroundings, the electric fish will slowly approach the foreign body with the tail.…”

“…Even in plants [1] and single-cell creatures [2,3], electrical signals are recorded. For the unique cases of electric eels (electrophorus electricus) and electric rays, they can sense fishes or animals in surrounding water with weak electrical pulses, and stun their preys with huge electrical discharges [4,5].…”