@article {647, title = {A review of the reproductive biology of mormyroid~fishes: An emerging model for biomedical research}, journal = {Journal of Experimental Zoology Part B: Molecular and Developmental EvolutionJournal of Experimental Zoology Part B: Molecular and Developmental EvolutionJ Exp Zool B Mol Dev Evol}, volume = {342}, year = {2024}, month = {2024/05/01}, pages = {144 - 163}, publisher = {John Wiley \& Sons, Ltd}, abstract = {Abstract Mormyroidea is a superfamily of weakly electric African fishes with great potential as a model in a variety of biomedical research areas including systems neuroscience, muscle cell and craniofacial development, ion channel biophysics, and flagellar/ciliary biology. However, they are currently difficult to breed in the laboratory setting, which is essential for any tractable model organism. As such, there is a need to better understand the reproductive biology of mormyroids to breed them more reliably in the laboratory to effectively use them as a biomedical research model. This review seeks to (1)~briefly highlight the biomedically relevant phenotypes of mormyroids and (2) compile information about mormyroid reproduction including sex differences, breeding season, sexual maturity, gonads, gametes, and courtship/spawning behaviors. We also highlight areas of mormyroid reproductive biology that are currently unexplored and/or have the potential for further investigation that may provide insights into more successful mormyroid laboratory breeding methods.}, keywords = {biomedicine, electric fish, mormyrid, reproduction, teleost}, isbn = {1552-5007}, url = {https://doi.org/10.1002/jez.b.23242}, author = {Saunders, Alyssa N. and Jason R. Gallant} } @article {626, title = {Transcriptome-wide single nucleotide polymorphisms related to electric organ discharge differentiation among African weakly electric fish species.}, journal = {PLoS One}, volume = {15}, year = {2020}, month = {2020}, pages = {e0240812}, abstract = {

African weakly electric fish of the mormyrid genus Campylomormyrus generate pulse-type electric organ discharges (EODs) for orientation and communication. Their pulse durations are species-specific and elongated EODs are a derived trait. So far, differential gene expression among tissue-specific transcriptomes across species with different pulses and point mutations in single ion channel genes indicate a relation of pulse duration and electrocyte geometry/excitability. However, a comprehensive assessment of expressed Single Nucleotide Polymorphisms (SNPs) throughout the entire transcriptome of African weakly electric fish, with the potential to identify further genes influencing EOD duration, is still lacking. This is of particular value, as discharge duration is likely based on multiple cellular mechanisms and various genes. Here we provide the first transcriptome-wide SNP analysis of African weakly electric fish species (genus Campylomormyrus) differing by EOD duration to identify candidate genes and cellular mechanisms potentially involved in the determination of an elongated discharge of C. tshokwe. Non-synonymous substitutions specific to C. tshokwe were found in 27 candidate genes with inferred positive selection among Campylomormyrus species. These candidate genes had mainly functions linked to transcriptional regulation, cell proliferation and cell differentiation. Further, by comparing gene annotations between C. compressirostris (ancestral short EOD) and C. tshokwe (derived elongated EOD), we identified 27 GO terms and 2 KEGG pathway categories for which C. tshokwe significantly more frequently exhibited a species-specific expressed substitution than C. compressirostris. The results indicate that transcriptional regulation as well cell proliferation and differentiation take part in the determination of elongated pulse durations in C. tshokwe. Those cellular processes are pivotal for tissue morphogenesis and might determine the shape of electric organs supporting the observed correlation between electrocyte geometry/tissue structure and discharge duration. The inferred expressed SNPs and their functional implications are a valuable resource for future investigations on EOD durations.

}, keywords = {Animals, electric fish, electric organ, Electricity, Gene Expression, Gene Expression Profiling, Gene Expression Regulation, Phenotype, Polymorphism, Single Nucleotide, Species Specificity, transcriptome}, issn = {1932-6203}, doi = {10.1371/journal.pone.0240812}, author = {Canitz, Julia and Kirschbaum, Frank and Ralph Tiedemann} } @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} } @article {410, title = {Differentiation of morphology, genetics and electric signals in a region of sympatry between sister species of African electric fish (Mormyridae)}, journal = {Journal of Evolutionary Biology}, volume = {21}, number = {4}, year = {2008}, note = {312QYTimes Cited:5Cited References Count:70}, month = {Jul}, pages = {1030-1045}, abstract = {

Mormyrid fishes produce and sense weak electric organ discharges (EODs) for object detection and communication, and they have been increasingly recognized as useful model organisms for studying signal evolution and speciation. EOD waveform variation can provide important clues to sympatric species boundaries between otherwise similar or morphologically cryptic forms. Endemic to the watersheds of Gabon (Central Africa), Ivindomyrus marchei and Ivindomyrus opdenboschi are morphologically similar to one another. Using morphometric, electrophysiological and molecular characters [cytochrome b sequences and amplified fragment length polymorphism (AFLP) genotypes], we investigated to what extent these nominal mormyrid species have diverged into biological species. Our sampling covered the known distribution of each species with a focus on the Ivindo River, where the two taxa co-occur. An overall pattern of congruence among datasets suggests that I. opdenboschi and I. marchei are mostly distinct. Electric signal analysis showed that EODs of I. opdenboschi tend to have a smaller initial head-positive peak than those of I. marchei, and they often possess a small third waveform peak that is typically absent in EODs of I. marchei. Analysis of sympatric I. opdenboschi and I. marchei populations revealed slight, but significant, genetic partitioning between populations based on AFLP data (F-ST approximate to 0.04). Taken separately, however, none of the characters we evaluated allowed us to discriminate two completely distinct or monophyletic groups. Lack of robust separation on the basis of any single character set may be a consequence of incomplete lineage sorting due to recent ancestry and/or introgressive hybridization. Incongruence between genetic datasets in one individual, which exhibited a mitochondrial haplotype characteristic of I. marchei but nevertheless fell within a genetic cluster of I. opdenboschi based on AFLP genotypes, suggests that a low level of recent hybridization may also be contributing to patterns of character variation in sympatry. Nevertheless, despite less than perfect separability based on any one dataset and inconclusive evidence for complete reproductive isolation between them in the Ivindo River, we find sufficient evidence to support the existence of two distinctive species, I. opdenboschi and I. marchei, even if not \’biological species\’ in the Mayrian sense.

}, keywords = {adaptive radiation, aflp, electric fish, electric organ discharge, gnathonemus-petersii mormyridae, introgression, markers, mitochondrial-DNA, mormyroidea, phylogeny, population-structure, reproductive isolation, speciation, teleostei}, isbn = {1010-061X}, url = {://000256687100010}, author = {S{\'e}bastien Lavou{\'e} and John P Sullivan and Matthew E Arnegard and Carl D Hopkins} } @article {893, title = {De novo assembly and characterization of the skeletal muscle and electric organ transcriptomes of the African weakly-electric fish Campylomormyrus compressirostris (Mormyridae, Teleostei)}, journal = {Molecular Ecology Resources}, year = {2014}, month = {03/2014}, pages = {n/a - n/a}, keywords = {cSSR, electric fish, electric organ, skeletal muscle, transcriptome}, doi = {10.1111/1755-0998.12260}, author = {Lamanna, Francesco and Frank Kirschbaum and Ralph Tiedemann} }