@article {670, title = {Gene expression correlates and mechanistic insights into electric organ discharge duration changes in mormyrid electric fish}, journal = {Journal of Experimental Biology}, volume = {228}, year = {2025}, month = {Jun-01-2025}, abstract = {

Electric organ discharge (EOD) duration in African weakly electric fish (Mormyridae) is the most variable waveform component between species and the basis for distinguishing species-specific signals. EOD duration is thought to be influenced by morphological and physiological features of electrocytes (the cells that comprise the electric organ), but the mechanistic details are poorly understood. It has long been known that EOD duration is modulated by androgen hormones, affording an opportunity to identify gene expression correlates of EOD duration differences. We induced EOD elongation in the mormyrid Brienomyrus brachyistius by administering 17\α-methyltestosterone (17\αMT) to three treatment groups: control (no 17\αMT exposure), T1day and T8day (samples taken 1 and 8 days after a single exposure to 17\αMT, respectively). We then performed RNAseq, differential gene expression and functional enrichment analysis to detect gene expression changes during EOD duration change. Our analyses indicate 44 genes whose expression changed in tandem with EOD elongation and include genes responsible for actin filaments and microtubules, extracellular matrix organization and membrane lipid metabolism. Additionally, we found expression changes in one Na+ channel \β-subunit, and five voltage-gated K+ channels. Together, these genes point toward specific cellular processes that contribute to morphological and physiological changes that contribute to EOD duration changes.

}, keywords = {Androgen hormones, electrocyte, K+ channel, Na+ channel, Testosterone}, issn = {0022-0949, 1477-9145}, doi = {10.1242/jeb.249548}, url = {https://doi.org/10.1242/jeb.249548}, author = {Losilla, Mauricio and Gallant, Jason R.} } @article {554, title = {The genome and adult somatic transcriptome of the mormyrid electric fish Paramormyrops kingsleyae}, journal = {Genome Biology and Evolution}, year = {2017}, month = {Dec-12-2017}, abstract = {

Several studies have begun to elucidate the genetic and developmental processes underlying major vertebrate traits. Few of these traits have evolved repeatedly in vertebrates, preventing the analysis of molecular mechanisms underlying these traits comparatively. Electric organs have evolved multiple times among vertebrates, presenting a unique opportunity to understand the degree of constraint and repeatability of the evolutionary processes underlying novel vertebrate traits. As there is now a completed genome sequence representing south american electric eels, we were motivated to obtain genomic sequence from a linage that independently evolved electric organs to facilitate future comparative analyses of the evolution and development of electric organs. We report here the sequencing and de-novo assembly of the genome of the mormyrid Paramormyrops kingsleyae using short-read sequencing. In addition, we have completed a somatic transcriptome from 11 tissues to construct a gene expression atlas of predicted genes from this assembly, enabling us to identify candidate housekeeping genes as well as genes differentially expressed in the major somatic tissues of the mormyrid electric fish. We anticipate that this resource will greatly facilitate comparative studies on the evolution and development of electric organs and electroreceptors.

}, doi = {10.1093/gbe/evx265}, url = {http://academic.oup.com/gbe/advance-article/doi/10.1093/gbe/evx265/4731783}, author = {Jason R. Gallant and Losilla, Mauricio and Tomlinson, Chad and Warren, Wesley C} } @article {539, title = {Electric Fish Genomics: Progress, Prospects, and New Tools for Neuroethology}, journal = {Journal of Physiology-Paris}, year = {2016}, month = {Jan-10-2016}, abstract = {

Electric fish have served as a model system in biology since the 18th century, providing deep insight into the nature of bioelectrogenesis, the molecular structure of the synapse, and brain circuitry underlying complex behavior. Neuroethologists have collected extensive phenotypic data that span biological levels of analysis from molecules to ecosystems. This phenotypic data, together with genomic resources obtained over the past decades, have motivated new and exciting hypotheses that position the weakly electric fish model to address fundamental 21st century biological questions. This review article considers the molecular data collected for weakly electric fish over the past three decades, and the insights that data of this nature has motivated. For readers relatively new to molecular genetics techniques, we also provide a table of terminology aimed at clarifying the numerous acronyms and techniques that accompany this field. Next, we pose a research agenda for expanding genomic resources for electric fish research over the next 10 years. We conclude by considering some of the exciting research prospects for neuroethology that electric fish genomics may offer over the coming decades, if the electric fish community is successful in these endeavors.

}, keywords = {CRISPR, electric fish, genome editing, genomics, transcriptomics, transgenics}, issn = {09284257}, doi = {10.1016/j.jphysparis.2016.10.003}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0928425716300079}, author = {Pitchers, William R. and Savvas J. Constantinou and Losilla, Mauricio and Jason R. Gallant} }