TY - JOUR A1 - Nagel, Rebecca A1 - Kirschbaum, Frank A1 - Tiedemann, Ralph T1 - Electric organ discharge diversification in mormyrid weakly electric fish is associated with differential expression of voltage-gated ion channel genes JF - Journal of comparative physiology : A, Neuroethology, sensory, neural, and behavioral physiology N2 - 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. KW - Weakly electric fish KW - Ion channels KW - Electric organ KW - Gene expression KW - Campylomormyrus Y1 - 2017 U6 - https://doi.org/10.1007/s00359-017-1151-2 SN - 0340-7594 SN - 1432-1351 VL - 203 SP - 183 EP - 195 PB - Springer CY - New York ER - TY - JOUR A1 - Valente, Luis A1 - Illera, Juan Carlos A1 - Havenstein, Katja A1 - Pallien, Tamara A1 - Etienne, Rampal S. A1 - Tiedemann, Ralph T1 - Equilibrium Bird Species Diversity in Atlantic Islands JF - Current biology Y1 - 2017 U6 - https://doi.org/10.1016/j.cub.2017.04.053 SN - 0960-9822 SN - 1879-0445 VL - 27 SP - 1660 EP - + PB - Cell Press CY - Cambridge ER - TY - JOUR A1 - Dominguez, Marisol A1 - Tiedemann, Ralph A1 - Reboreda, Juan C. A1 - Segura, Luciano A1 - Tittarelli, Fabian A1 - Mahler, Bettina T1 - Genetic structure reveals management units for the yellow cardinal (Gubernatrix cristata), endangered by habitat loss and illegal trapping JF - Conservation genetics KW - Genetic structure KW - Gubernatrix cristata KW - Management units KW - MtDNA KW - Microsatellites KW - Hybrids Y1 - 2017 U6 - https://doi.org/10.1007/s10592-017-0964-4 SN - 1566-0621 SN - 1572-9737 VL - 18 SP - 1131 EP - 1140 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Zhu, Fangjun A1 - Schlupp, Ingo A1 - Tiedemann, Ralph T1 - Allele-specific expression at the androgen receptor alpha gene in a hybrid unisexual fish, the Amazon molly (Poecilia formosa) JF - PLoS one N2 - The all-female Amazon molly (Poecilia formosa) is the result of a hybridization of the Atlantic molly (P. mexicana) and the sailfin molly (P. latipinna) approximately 120,000 years ago. As a gynogenetic species, P. formosa needs to copulate with heterospecific males including males from one of its bisexual ancestral species. However, the sperm only triggers embryo genesis of the diploid eggs. The genetic information of the sperm donor typically will not contribute to the next generation of P. formosa. Hence, P. formosa possesses generally one allele from each of its ancestral species at any genetic locus. This raises the question whether both ancestral alleles are equally expressed in P. formosa. Allele-specific expression (ASE) has been previously assessed in various organisms, e.g., human and fish, and ASE was found to be important in the context of phenotypic variability and disease. In this study, we utilized Real-Time PCR techniques to estimate ASE of the androgen receptor alpha (ara) gene in several distinct tissues of Amazon mollies. We found an allelic bias favoring the maternal ancestor (P. mexicana) allele in ovarian tissue. This allelic bias was not observed in the gill or the brain tissue. Sequencing of the promoter regions of both alleles revealed an association between an Indel in a known CpG island and differential expression. Future studies may reveal whether our observed cis-regulatory divergence is caused by an ovary-specific trans-regulatory element, preferentially activating the allele of the maternal ancestor. Y1 - 2017 U6 - https://doi.org/10.1371/journal.pone.0186411 SN - 1932-6203 VL - 12 PB - PLoS CY - San Fransisco ER - TY - GEN A1 - Zhu, Fangjun A1 - Schlupp, Ingo A1 - Tiedemann, Ralph T1 - Allele-specific expression at the androgen receptor alpha gene in a hybrid unisexual fish, the Amazon molly (Poecilia formosa) N2 - The all-female Amazon molly (Poecilia formosa) is the result of a hybridization of the Atlantic molly (P. mexicana) and the sailfin molly (P. latipinna) approximately 120,000 years ago. As a gynogenetic species, P. formosa needs to copulate with heterospecific males including males from one of its bisexual ancestral species. However, the sperm only triggers embryogenesis of the diploid eggs. The genetic information of the sperm donor typically will not contribute to the next generation of P. formosa. Hence, P. formosa possesses generally one allele from each of its ancestral species at any genetic locus. This raises the question whether both ancestral alleles are equally expressed in P. formosa. Allele-specific expression (ASE) has been previously assessed in various organisms, e.g., human and fish, and ASE was found to be important in the context of phenotypic variability and disease. In this study, we utilized Real-Time PCR techniques to estimate ASE of the androgen receptor alpha (arα) gene in several distinct tissues of Amazon mollies. We found an allelic bias favoring the maternal ancestor (P. mexicana) allele in ovarian tissue. This allelic bias was not observed in the gill or the brain tissue. Sequencing of the promoter regions of both alleles revealed an association between an Indel in a known CpG island and differential expression. Future studies may reveal whether our observed cis-regulatory divergence is caused by an ovary-specific trans-regulatory element, preferentially activating the allele of the maternal ancestor. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 395 Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-403875 ER - TY - JOUR A1 - Zhu, Fangjun A1 - Schlupp, Ingo A1 - Tiedemann, Ralph T1 - Allele-specific expression at the androgen receptor alpha gene in a hybrid unisexual fish, the Amazon molly (Poecilia formosa) JF - PLoS one N2 - The all-female Amazon molly (Poecilia formosa) is the result of a hybridization of the Atlantic molly (P. mexicana) and the sailfin molly (P. latipinna) approximately 120,000 years ago. As a gynogenetic species, P. formosa needs to copulate with heterospecific males including males from one of its bisexual ancestral species. However, the sperm only triggers embryogenesis of the diploid eggs. The genetic information of the sperm donor typically will not contribute to the next generation of P. formosa. Hence, P. formosa possesses generally one allele from each of its ancestral species at any genetic locus. This raises the question whether both ancestral alleles are equally expressed in P. formosa. Allele-specific expression (ASE) has been previously assessed in various organisms, e.g., human and fish, and ASE was found to be important in the context of phenotypic variability and disease. In this study, we utilized Real-Time PCR techniques to estimate ASE of the androgen receptor alpha (arα) gene in several distinct tissues of Amazon mollies. We found an allelic bias favoring the maternal ancestor (P. mexicana) allele in ovarian tissue. This allelic bias was not observed in the gill or the brain tissue. Sequencing of the promoter regions of both alleles revealed an association between an Indel in a known CpG island and differential expression. Future studies may reveal whether our observed cis-regulatory divergence is caused by an ovary-specific trans-regulatory element, preferentially activating the allele of the maternal ancestor. Y1 - 2017 U6 - https://doi.org/10.1371/journal.pone.0186411 SN - 1932-6203 VL - 12 IS - 10 SP - 1 EP - 14 PB - PLoS CY - Lawrence, Kan. ER - TY - GEN A1 - Sammler, Svenja A1 - Ketmaier, Valerio A1 - Havenstein, Katja A1 - Krause, Ulrike A1 - Curio, Eberhard A1 - Tiedemann, Ralph T1 - Mitochondrial control region I and microsatellite analyses of endangered Philippine hornbill species (Aves; Bucerotidae) detect gene flow between island populations and genetic diversity loss N2 - Background: The Visayan Tarictic Hornbill (Penelopides panini) and the Walden's Hornbill (Aceros waldeni) are two threatened hornbill species endemic to the western islands of the Visayas that constitute - between Luzon and Mindanao - the central island group of the Philippine archipelago. In order to evaluate their genetic diversity and to support efforts towards their conservation, we analyzed genetic variation in similar to 600 base pairs (bp) of the mitochondrial control region I and at 12-19 nuclear microsatellite loci. The sampling covered extant populations, still occurring only on two islands (P. panini: Panay and Negros, A. waldeni: only Panay), and it was augmented with museum specimens of extinct populations from neighboring islands. For comparison, their less endangered (= more abundant) sister taxa, the Luzon Tarictic Hornbill (P. manillae) from the Luzon and Polillo Islands and the Writhed Hornbill (A. leucocephalus) from Mindanao Island, were also included in the study. We reconstructed the population history of the two Penelopides species and assessed the genetic population structure of the remaining wild populations in all four species. Results: Mitochondrial and nuclear data concordantly show a clear genetic separation according to the island of origin in both Penelopides species, but also unravel sporadic over-water movements between islands. We found evidence that deforestation in the last century influenced these migratory events. Both classes of markers and the comparison to museum specimens reveal a genetic diversity loss in both Visayan hornbill species, P. panini and A. waldeni, as compared to their more abundant relatives. This might have been caused by local extinction of genetically differentiated populations together with the dramatic decline in the abundance of the extant populations. Conclusions: We demonstrated a loss in genetic diversity of P. panini and A. waldeni as compared to their sister taxa P. manillae and A. leucocephalus. Because of the low potential for gene flow and population exchange across islands, saving of the remaining birds of almost extinct local populations - be it in the wild or in captivity - is particularly important to preserve the species' genetic potential. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 378 KW - biogeography KW - bucerotidae KW - conservation genetics KW - genetic diversity loss KW - microsatellites KW - mitochondrial control region I KW - Philippine archipelago KW - phylogeography Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-401108 ER - TY - GEN A1 - Sammler, Svenja A1 - Bleidorn, Christoph A1 - Tiedemann, Ralph T1 - Full mitochondrial genome sequences of two endemic Philippine hornbill species (Aves: Bucerotidae) provide evidence for pervasive mitochondrial DNA recombination N2 - Background: Although nowaday it is broadly accepted that mitochondrial DNA (mtDNA) may undergo recombination, the frequency of such recombination remains controversial. Its estimation is not straightforward, as recombination under homoplasmy (i.e., among identical mt genomes) is likely to be overlooked. In species with tandem duplications of large mtDNA fragments the detection of recombination can be facilitated, as it can lead to gene conversion among duplicates. Although the mechanisms for concerted evolution in mtDNA are not fully understood yet, recombination rates have been estimated from "one per speciation event" down to 850 years or even "during every replication cycle". Results: Here we present the first complete mt genome of the avian family Bucerotidae, i.e., that of two Philippine hornbills, Aceros waldeni and Penelopides panini. The mt genomes are characterized by a tandemly duplicated region encompassing part of cytochrome b, 3 tRNAs, NADH6, and the control region. The duplicated fragments are identical to each other except for a short section in domain I and for the length of repeat motifs in domain III of the control region. Due to the heteroplasmy with regard to the number of these repeat motifs, there is some size variation in both genomes; with around 21,657 bp (A. waldeni) and 22,737 bp (P. panini), they significantly exceed the hitherto longest known avian mt genomes, that of the albatrosses. We discovered concerted evolution between the duplicated fragments within individuals. The existence of differences between individuals in coding genes as well as in the control region, which are maintained between duplicates, indicates that recombination apparently occurs frequently, i. e., in every generation. Conclusions: The homogenised duplicates are interspersed by a short fragment which shows no sign of recombination. We hypothesize that this region corresponds to the so-called Replication Fork Barrier (RFB), which has been described from the chicken mitochondrial genome. As this RFB is supposed to halt replication, it offers a potential mechanistic explanation for frequent recombination in mitochondrial genomes. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 367 KW - d-loop region KW - concerted evolution KW - gene order KW - birds KW - phylogeny KW - heteroplasmy KW - organization KW - duplication KW - vertebrates KW - alignment Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400889 ER -