title: Electric organ discharge diversification in mormyrid weakly electric fish is associated with differential expression of voltage-gated ion channel genes.
abstract: In mormyrid weakly electric fish, the electric organ discharge (EOD) is used for species recognition, orientation and prey localization. Produced in the muscle-derived adult electric organ, the EOD exhibits a wide diversity across species in both waveform and duration. While certain defining EOD characteristics can be linked to anatomical features of the electric organ, many factors underlying EOD differentiation are yet unknown. Here, we report the differential expression of 13 Kv1 voltage-gated potassium channel genes, two inwardly rectifying potassium channel genes, two previously studied sodium channel genes and an ATPase pump in two sympatric species of the genus Campylomormyrus in both the adult electric organ and skeletal muscle. Campylomormyrus compressirostris displays a basal EOD, largely unchanged during development, while C. tshokwe has an elongated, putatively derived discharge. We report an upregulation in all Kv1 genes in the electric organ of Campylomormyrus tshokwe when compared to both skeletal muscle and C. compressirostris electric organ. This pattern of upregulation in a species with a derived EOD form suggests that voltage-gated potassium channels are potentially involved in the diversification of the EOD signal among mormyrid weakly electric fish.
authors.affiliation: Institute of Biochemistry and Biology, Unit of Evolutionary Biology/Systematic Zoology, University of Potsdam, Karl-Liebknecht-Str. 24-25, House 26, 14476, Potsdam, Germany.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Nagel
authors.affiliation: Faculty of Life Sciences, Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Unit of Biology and Ecology of Fishes, Humboldt University of Berlin, Philippstr. 13, House 16, 10115, Berlin, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Kirschbaum
authors.affiliation: Institute of Biochemistry and Biology, Unit of Evolutionary Biology/Systematic Zoology, University of Potsdam, Karl-Liebknecht-Str. 24-25, House 26, 14476, Potsdam, Germany. tiedeman@uni-potsdam.de.
authors.forename: Ralph
authors.initials: R
authors.lastname: Tiedemann
mesh_terms: D000818:Animals; D004555:Electric Fish / Q000235:genetics* / Q000378:metabolism*; D004557:Electric Organ / Q000502:physiology*; D005260:Female; D015870:Gene Expression; D024642:Potassium Channels, Voltage-Gated / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: D024642:Potassium Channels, Voltage-Gated
keywords: Campylomormyrus; Electric organ; Gene expression; Ion channels; Weakly electric fish