@article {499, title = {Species delimitation and phylogenetic relationships in a genus of African weakly-electric fishes (Osteoglossiformes, Mormyridae, Campylomormyrus)}, journal = {Molecular Phylogenetics and Evolution}, year = {2016}, month = {Jan-04-2016}, abstract = {

African weakly-electric fishes (Mormyridae) are able to communicate through species-specific electric signals; this feature might have favoured the evolutionary radiation observed in this family (over 200 species) by acting as an effective pre-zygotic isolation mechanism. In the present study we used mitochondrial (cytb) and nuclear (rps7, scn4aa) markers in order to reconstruct a species-phylogeny and identify species boundaries for the genus Campylomormyrus, by applying inference methods based on the multispecies coalescent model. Additionally, we employed 16 microsatellite markers, landmark-based morphometric measurements, and electro-physiological analyses as independent lines of evidence to the results obtained from the sequence data. The results show that groups that are morphologically different are also significantly divergent at the genetic level, whereas morphologically similar groups, displaying dissimilar electric signals, do not show enough genetic diversity to be considered separate species. Furthermore, the data confirm the presence of a yet undescribed species within the genus Campylomormyrus.

}, keywords = {Campylomormyrus, Geometric morphometrics, Microsatellites, Mormyridae, Multispecies-coalescent, Species-delimitation}, issn = {10557903}, doi = {10.1016/j.ympev.2016.04.035}, url = {http://linkinghub.elsevier.com/retrieve/pii/S1055790316300781}, author = {Lamanna, Francesco and Frank Kirschbaum and Ernst, Anja R.R. and Philine G.D. Feulner and Victor Mamonekene and Paul, Christiane and Ralph Tiedemann} } @article {478, title = {Cross-tissue and cross-species analysis of gene expression in skeletal muscle and electric organ of African weakly-electric fish (Teleostei; Mormyridae)}, journal = {BMC Genomics}, volume = {16}, year = {2015}, month = {Jan-12-2015}, abstract = {

Background: African weakly-electric fishes of the family Mormyridae are able to produce and perceive weak electric signals (typically less than one volt in amplitude) owing to the presence of a specialized, muscle-derived electric organ (EO) in their tail region. Such electric signals, also known as Electric Organ Discharges (EODs), are used for objects/prey localization, for the identification of conspecifics, and in social and reproductive behaviour. This feature might have promoted the adaptive radiation of this family by acting as an effective pre-zygotic isolation mechanism. Despite the physiological and evolutionary importance of this trait, the investigation of the genetic basis of its function and modification has so far remained limited. In this study, we aim at: i) identifying constitutive differences in terms of gene expression between electric organ and skeletal muscle (SM) in two mormyrid species of the genus Campylomormyrus: C. compressirostris and C. tshokwe, and ii) exploring cross-specific patterns of gene expression within the two tissues among C. compressirostris, C. tshokwe, and the outgroup species Gnathonemus petersii.
Results: Twelve paired-end (100 bp) strand-specific RNA-seq Illumina libraries were sequenced, producing circa 330 M quality-filtered short read pairs. The obtained reads were assembled de novo into four reference transcriptomes. In silico cross-tissue DE-analysis allowed us to identify 271 shared differentially expressed genes between EO and SM in C. compressirostris and C.tshokwe. Many of these genes correspond to myogenic factors, ion channels and pumps, and genes involved in several metabolic pathways. Cross-species analysis has revealed that the electric organ transcriptome is more variable in terms of gene expression levels across species than the skeletal muscle transcriptome.
Conclusions: The data obtained indicate that: i) the loss of contractile activity and the decoupling of the excitation-contraction processes are reflected by the down-regulation of the corresponding genes in the electric organ\’s transcriptome; ii) the metabolic activity of the EO might be specialized towards the production and turn-over of membrane structures; iii) several ion channels are highly expressed in the EO in order to increase excitability; iv) several myogenic factors might be down-regulated by transcription repressors in the EO.

}, doi = {10.1186/s12864-015-1858-9}, url = {http://www.biomedcentral.com/1471-2164/16/668}, author = {Lamanna, Francesco and Frank Kirschbaum and Waurick, Isabelle and Dieterich, Christoph and Ralph Tiedemann} } @article {453, 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}, volume = {14}, year = {2014}, month = {Jan-11-2014}, pages = {1222 - 1230}, abstract = {

African weakly electric fishes (Mormyridae) underwent an outstanding adaptive radiation (about 200 species), puta-tively owing to their ability to communicate through species-specific weak electric signals. The electric organdischarge (EOD) is produced by muscle-derived electrocytes organized in piles to form an electric organ. Despite theimportance of this trait as a prezygotic isolation mechanism, genomic resources remained limited. We present here afirst draft of the skeletal muscle and electric organ transcriptomes from the weakly electric fish species Camp-ylomormyrus compressirostris, obtained using the Illumina HiSeq2000 sequencing technology. Approximately 6.8Gbp of cDNA sequence data were produced from both tissues, resulting in 57 268 109 raw reads for the skeletal mus-cle and 46 934 923 for the electric organ, and assembled de novo into 46 143 and 89 270 contigs, respectively. About50\% of both transcriptomes were annotated after protein databases search. The two transcriptomes show similarprofiles in terms of Gene Ontology categories composition. We identified several candidate genes which are likely toplay a central role in the production and evolution of the electric signal. For most of these genes, and for many otherhousekeeping genes, we were able to obtain the complete or partial coding DNA sequences (CDS), which can beused for the development of primers to be utilized in qRT-PCR experiments. We present also the complete mitochon-drial genome and compare it to those available from other weakly electric fish species. Additionally, we located 1671SSR-containing regions with their flanking sites and designed the relative primers. This study establishes a first stepin the development of genomic tools aimed at understanding the role of electric communication during speciation

}, doi = {10.1111/men.2014.14.issue-610.1111/1755-0998.12260}, url = {http://doi.wiley.com/10.1111/men.2014.14.issue-6http://doi.wiley.com/10.1111/1755-0998.12260}, author = {Lamanna, Francesco and Frank Kirschbaum and Ralph Tiedemann} } @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} }