TY  - JOUR
A1  - Paul, Christiane
A1  - Mamonekene, Victor
A1  - Vater, Marianne
A1  - Feulner, Philine G. D.
A1  - Engelmann, Jacob
A1  - Tiedemann, Ralph
A1  - Kirschbaum, Frank
T1  - Comparative histology of the adult electric organ among four species of the genus Campylomormyrus (Teleostei: Mormyridae)
JF  - Journal of comparative physiology : A, Neuroethology, sensory, neural, and behavioral physiology
N2  - The electric organ (EO) of weakly electric mormyrids consists of flat, disk-shaped electrocytes with distinct anterior and posterior faces. There are multiple species-characteristic patterns in the geometry of the electrocytes and their innervation. To further correlate electric organ discharge (EOD) with EO anatomy, we examined four species of the mormyrid genus Campylomormyrus possessing clearly distinct EODs. In C. compressirostris, C. numenius, and C. tshokwe, all of which display biphasic EODs, the posterior face of the electrocytes forms evaginations merging to a stalk system receiving the innervation. In C. tamandua that emits a triphasic EOD, the small stalks of the electrocyte penetrate the electrocyte anteriorly before merging on the anterior side to receive the innervation. Additional differences in electrocyte anatomy among the former three species with the same EO geometry could be associated with further characteristics of their EODs. Furthermore, in C. numenius, ontogenetic changes in EO anatomy correlate with profound changes in the EOD. In the juvenile the anterior face of the electrocyte is smooth, whereas in the adult it exhibits pronounced surface foldings. This anatomical difference, together with disparities in the degree of stalk furcation, probably contributes to the about 12 times longer EOD in the adult.
KW  - Mormyridae
KW  - Campylomormyrus
KW  - Electric organ discharge
KW  - Electrocyte geometry
KW  - Electric organ ontogeny
Y1  - 2015
U6  - https://doi.org/10.1007/s00359-015-0995-6
SN  - 0340-7594
SN  - 1432-1351
VL  - 201
IS  - 4
SP  - 357
EP  - 374
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Di Giacomo, Adrian S.
A1  - Di Giacomo, Alejandro G.
A1  - Kliger, Rafi
A1  - Reboreda, Juan C.
A1  - Tiedemann, Ralph
A1  - Mahler, Bettina
T1  - No evidence of genetic variation in microsatellite and mitochondrial DNA markers among remaining populations of the Strange-tailed Tyrant Alectrurus risora, an endangered grassland species
JF  - Bird conservation international
N2  - The Strange-tailed Tyrant Alectrurus risora (Aves: Tyrannidae) is an endemic species of southern South American grasslands that suffered a 90% reduction of its original distribution due to habitat transformation. This has led the species to be classified as globally Vulnerable. By the beginning of the last century, populations were partially migratory and moved south during the breeding season. Currently, the main breeding population inhabits the Ibera wetlands in the province of Corrientes, north-east Argentina, where it is resident all year round. There are two remaining small populations in the province of Formosa, north-east Argentina, and in southern Paraguay, which are separated from the main population by the Parana-Paraguay River and its continuous riverine forest habitat. The populations of Corrientes and Formosa are separated by 300 km and the grasslands between populations are non-continuous due to habitat transformation. We used mtDNA sequences and eight microsatellite loci to test if there were evidences of genetic isolation between Argentinean populations. We found no evidence of genetic structure between populations (Phi(ST) = 0.004, P = 0.32; Fst = 0.01, P = 0.06), which can be explained by either retained ancestral polymorphism or by dispersal between populations. We found no evidence for a recent demographic bottleneck in nuclear loci. Our results indicate that these populations could be managed as a single conservation unit on a regional scale. Conservation actions should be focused on preserving the remaining network of areas with natural grasslands to guarantee reproduction, dispersal and prevent further decline of populations.
Y1  - 2015
U6  - https://doi.org/10.1017/S0959270914000203
SN  - 0959-2709
SN  - 1474-0001
VL  - 25
IS  - 2
SP  - 127
EP  - 138
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Stoof-Leichsenring, Kathleen Rosemarie
A1  - Herzschuh, Ulrike
A1  - Pestryakova, Luidmila Agafyevna
A1  - Klemm, Juliane
A1  - Epp, Laura Saskia
A1  - Tiedemann, Ralph
T1  - Genetic data from algae sedimentary DNA reflect the influence of environment over geography
JF  - Scientific reports
N2  - Genetic investigations on eukaryotic plankton confirmed the existence of modern biogeographic patterns, but analyses of palaeoecological data exploring the temporal variability of these patterns have rarely been presented. Ancient sedimentary DNA proved suitable for investigations of past assemblage turnover in the course of environmental change, but genetic relatedness of the identified lineages has not yet been undertaken. Here, we investigate the relatedness of diatom lineages in Siberian lakes along environmental gradients (i.e. across treeline transects), over geographic distance and through time (i.e. the last 7000 years) using modern and ancient sedimentary DNA. Our results indicate that closely-related Staurosira lineages occur in similar environments and less-related lineages in dissimilar environments, in our case different vegetation and co-varying climatic and limnic variables across treeline transects. Thus our study reveals that environmental conditions rather than geographic distance is reflected by diatom-relatedness patterns in space and time. We tentatively speculate that the detected relatedness pattern in Staurosira across the treeline could be a result of adaptation to diverse environmental conditions across the arctic boreal treeline, however, a geographically-driven divergence and subsequent repopulation of ecologically different habitats might also be a potential explanation for the observed pattern.
Y1  - 2015
U6  - https://doi.org/10.1038/srep12924
SN  - 2045-2322
VL  - 5
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Lamanna, Francesco
A1  - Kirschbaum, Frank
A1  - Waurick, Isabelle
A1  - Dieterich, Christoph
A1  - Tiedemann, Ralph
T1  - Cross-tissue and cross-species analysis of gene expression in skeletal muscle and electric organ of African weakly-electric fish (Teleostei; Mormyridae)
JF  - BMC genomics
N2  - 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.
Y1  - 2015
U6  - https://doi.org/10.1186/s12864-015-1858-9
SN  - 1471-2164
VL  - 16
PB  - BioMed Central
CY  - London
ER  - 
TY  - JOUR
A1  - Dolgener, N.
A1  - Freudenberger, L.
A1  - Schluck, M.
A1  - Schneeweiss, N.
A1  - Ibisch, P. L.
A1  - Tiedemann, Ralph
T1  - Environmental niche factor analysis (ENFA) relates environmental parameters to abundance and genetic diversity in an endangered amphibian, the fire-bellied-toad (Bombina bombina)
JF  - Conservation genetics
N2  - Increasing attempts are made to understand the factors responsible for both the demographic and genetic depletion in amphibian populations. Landscape genetics aims at a spatially explicit correlation of genetic population parameters to landscape features. Using data from the endangered fire-bellied toad Bombina bombina in Brandenburg (Northeastern Germany), we performed an environmental niche factor analysis (ENFA), relating demographic (abundance) and genetic (diversity at 17 microsatellite loci and partial sequences of the mitochondrial control region in 434 individuals from 16 populations) parameters to ecological and anthropogenic variables such as temperature, precipitation, soil wetness, water runoff, vegetation density, and road/traffic impact. We found significant correlations between road disturbance and observed heterozygosity and between soil wetness and mitochondrial diversity. As the influences of the environmental variables can differ between different indicators for genetic diversity, population size and abundance data, our ENFA-based landscape genetics approach allows us to put various aspects of long- versus short term effective population size and genetic connectivity into an ecological and spatially explicit context, enabling potentially even forecast assessment under future environmental scenarios.
KW  - Distribution modelling
KW  - ENFA
KW  - Genetic diversity
KW  - Fire-bellied toad
KW  - Landscape genetics
KW  - Road disturbance
Y1  - 2014
U6  - https://doi.org/10.1007/s10592-013-0517-4
SN  - 1566-0621
SN  - 1572-9737
VL  - 15
IS  - 1
SP  - 11
EP  - 21
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Dolgener, Nicola
A1  - Freudenberger, L.
A1  - Schneeweiss, N.
A1  - Ibisch, P. L.
A1  - Tiedemann, Ralph
T1  - Projecting current and potential future distribution of the Fire-bellied toad Bombina bombina under climate change in north-eastern Germany
JF  - Regional environmental change
N2  - Environmental change is likely to have a strong impact on biodiversity, and many species may shift their distribution in response. In this study, we aimed at projecting the availability of suitable habitat for an endangered amphibian species, the Fire-bellied toad Bombina bombina, in Brandenburg (north-eastern Germany). We modelled a potential habitat distribution map based on (1) a database with 10,581 presence records for Bombina from the years 1990 to 2009, (2) current estimates for ecogeographical variables (EGVs) and (3) the future projection of these EGVs according to the statistical regional model, respectively, the soil and water integrated model, applying the maximum entropy approach (Maxent). By comparing current and potential future distributions, we evaluated the projected change in distribution of suitable habitats and identified the environmental variables most associated with habitat suitability that turned out to be climatic variables related to the hydrological cycle. Under the applied scenario, our results indicate increasing habitat suitability in many areas and an extended range of suitable habitats. However, even if the environmental conditions in Brandenburg may change as predicted, it is questionable whether the Fire-bellied toad will truly benefit, as dispersal abilities of amphibian species are limited and strongly influenced by anthropogenic disturbances, that is, intensive agriculture, habitat destruction and fragmentation. Furthermore, agronomic pressure is likely to increase on productive areas with fertile soils and high water retention capacities, indeed those areas suitable for B. bombina. All these changes may affect temporary pond hydrology as well as the reproductive success and breeding phenology of toads.
KW  - Brandenburg
KW  - Climate change
KW  - Distribution modelling
KW  - Endangered species
KW  - Fire-bellied toad
KW  - Maxent
Y1  - 2014
U6  - https://doi.org/10.1007/s10113-013-0468-9
SN  - 1436-3798
SN  - 1436-378X
VL  - 14
IS  - 3
SP  - 1063
EP  - 1072
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Stoof-Leichsenring, Kathleen Rosemarie
A1  - Bernhardt, Nadine
A1  - Pestryakova, Luidmila Agafyevna
A1  - Epp, Laura Saskia
A1  - Herzschuh, Ulrike
A1  - Tiedemann, Ralph
T1  - A combined paleolimnological/genetic analysis of diatoms reveals divergent evolutionary lineages of Staurosira and Staurosirella (Bacillariophyta) in Siberian lake sediments along a latitudinal transect
JF  - Journal of paleolimnolog
N2  - Diatom diversity in lakes of northwest Yakutia (Siberia) was investigated by microscopic and genetic analysis of surface and cored lake sediments, to evaluate the use of sedimentary DNA for paleolimnological diatom studies and to identify obscure genetic diversity that cannot be detected by microscopic methods. Two short (76 and 73 bp) and one longer (577 bp) fragments of the ribulose 1,5-bisphosphate carboxylase/oxygenase (rbcL) gene, encoding the large subunit of the rbcL, were used as genetic markers. Diverse morphological assemblages of diatoms, dominated by small benthic fragilarioid taxa, were retrieved from the sediments of each lake. These minute fragilarioid taxa were examined by scanning electron microscopy, revealing diverse morphotypes in Staurosira and Staurosirella from the different lakes. Genetic analyses indicated a dominance of haplotypes that were assigned to fragilarioid taxa and less genetic diversity in other diatom taxa. The long rbcL_577 amplicon identified considerable diversification among haplotypes clustering within the Staurosira/Staurosirella genera, revealing 19 different haplotypes whose spatial distribution appears to be primarily related to the latitude of the lakes, which corresponds to a vegetation and climate gradient. Our rbcL markers are valuable tools for tracking differences between diatom lineages that are not visible in their morphologies. These markers revealed putatively high genetic diversity within the Staurosira/Staurosirella species complex, at a finer scale than is possible to resolve by microscopic determination. The rbcL markers may provide additional reliable information on the diversity of barely distinguishable minute benthic fragilarioids. Environmental sequencing may thus allow the tracking of spatial and temporal diversification in Siberian lakes, especially in the context of diatom responses to recent environmental changes, which remains a matter of controversy.
KW  - Arctic lake sediments
KW  - Diatoms
KW  - Environmental DNA
KW  - Intraspecific variation
KW  - RbcL
Y1  - 2014
U6  - https://doi.org/10.1007/s10933-014-9779-1
SN  - 0921-2728
SN  - 1573-0417
VL  - 52
IS  - 1-2
SP  - 77
EP  - 93
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Schedina, Ina-Maria
A1  - Pfautsch, Simone
A1  - Hartmann, Stefanie
A1  - Dolgener, N.
A1  - Polgar, Anika
A1  - Bianco, Pier Giorgio
A1  - Tiedemann, Ralph
A1  - Ketmaier, Valerio
T1  - Isolation and characterization of eight microsatellite loci in the brook lamprey Lampetra planeri (Petromyzontiformes) using 454 sequence data
JF  - Journal of fish biology
N2  - Eight polymorphic microsatellite loci were developed for the brook lamprey Lampetra planeri through 454 sequencing and their usefulness was tested in 45 individuals of both L. planeri and the river lamprey Lampetra fluviatilis. The number of alleles per loci ranged between two and five; the Italian and Irish populations had a mean expected heterozygosity of 0.388 and 0.424 and a mean observed heterozygosity of 0.418 and 0.411, respectively. (C) 2014 The Fisheries Society of the British Isles
KW  - conservation
KW  - population structure
KW  - species pair
Y1  - 2014
U6  - https://doi.org/10.1111/jfb.12470
SN  - 0022-1112
SN  - 1095-8649
VL  - 85
IS  - 3
SP  - 960
EP  - 964
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Lamanna, Francesco
A1  - Kirschbaum, Frank
A1  - Tiedemann, Ralph
T1  - De novo assembly and characterization of the skeletal muscle and electric organ transcriptomes of the African weakly electric fish Campylomormyrus compressirostris (Mormyridae, Teleostei)
JF  - Molecular ecology resources
N2  - African weakly electric fishes (Mormyridae) underwent an outstanding adaptive radiation (about 200 species), putatively owing to their ability to communicate through species-specific weak electric signals. The electric organ discharge (EOD) is produced by muscle-derived electrocytes organized in piles to form an electric organ. Despite the importance of this trait as a prezygotic isolation mechanism, genomic resources remained limited. We present here a first draft of the skeletal muscle and electric organ transcriptomes from the weakly electric fish species Campylomormyrus compressirostris, obtained using the Illumina HiSeq2000 sequencing technology. Approximately 6.8 Gbp of cDNA sequence data were produced from both tissues, resulting in 57268109 raw reads for the skeletal muscle and 46934923 for the electric organ, and assembled de novo into 46143 and 89270 contigs, respectively. About 50% of both transcriptomes were annotated after protein databases search. The two transcriptomes show similar profiles in terms of Gene Ontology categories composition. We identified several candidate genes which are likely to play a central role in the production and evolution of the electric signal. For most of these genes, and for many other housekeeping genes, we were able to obtain the complete or partial coding DNA sequences (CDS), which can be used for the development of primers to be utilized in qRT-PCR experiments. We present also the complete mitochondrial genome and compare it to those available from other weakly electric fish species. Additionally, we located 1671 SSR-containing regions with their flanking sites and designed the relative primers. This study establishes a first step in the development of genomic tools aimed at understanding the role of electric communication during speciation.
KW  - cSSR
KW  - electric fish
KW  - electric organ
KW  - skeletal muscle
KW  - transcriptome
Y1  - 2014
U6  - https://doi.org/10.1111/1755-0998.12260
SN  - 1755-098X
SN  - 1755-0998
VL  - 14
IS  - 6
SP  - 1222
EP  - 1230
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Nahavandi, Nahid
A1  - Plath, Martin
A1  - Tiedemann, Ralph
A1  - Mirzajani, Ali R.
T1  - Sexual and natural selection on morphological traits in a marine amphipod, Pontogammarus maeoticus (Sowinsky, 1894)
JF  - Marine biology research
N2  - Sexual selection often leads to sexual dimorphism, where secondary sexual traits are more expressed in the male sex. This may be due, for example, to increased fighting or mate-guarding abilities of males expressing those traits. We investigated sexually dimorphic traits in four populations of a marine amphipod, Pontogammarus maeoticus (Gammaridea: Pontogammaridae), the most abundant amphipod species in the sublittoral zone along the southern shoreline of the Caspian Sea. Male amphipods are typically larger in body size than females, and have relatively larger posterior gnathopods and antennae. However, it remains to be studied for most other body appendages whether or not, and to what extent, they are sexually dimorphic. Using Analysis of Covariance (ANCOVA), we compared the relationships between body size and trait expression for 35 metric characters between males and females, and among the four populations examined by performing three different Discriminant Function Analyses (DFA). We detected several thus far undescribed sexual dimorphic traits such as the seventh peraeopods or the epimeral plates. We also found that the size of the propodus of the first and second gnathopods increases with increasing body size, and this allometric increase was stronger in males than in females. Finally, we found that the degree of sexual dimorphism in the expression of the width of the third epimeral plate varies across sites, suggesting that differences in ecology might affect the strength of sexual selection in different populations.
KW  - Caspian Sea
KW  - crustacean
KW  - dimorphism
KW  - scramble competition
Y1  - 2011
U6  - https://doi.org/10.1080/17451001003713589
SN  - 1745-1000
VL  - 7
IS  - 2
SP  - 135
EP  - 146
PB  - Taylor & Francis Group
CY  - Oslo
ER  - 
TY  - JOUR
A1  - Sharma, Reeta
A1  - Stuckas, Heiko
A1  - Bhaskar, Ranjana
A1  - Khan, Imran
A1  - Goyal, Surendra Prakash
A1  - Tiedemann, Ralph
T1  - Genetically distinct population of Bengal tiger (Panthera tigris tigris) in Terai Arc Landscape (TAL) of India
JF  - Mammalian biology = Zeitschrift für Säugetierkunde
N2  - We analyzed mtDNA polymorphisms (a total of 741 bp from a part of conserved control region, ND5, ND2, Cyt b and 12S) in 91 scats and 12 tissue samples of Bengal tiger (Panthera tigris tigris) populations across Terai Arc Landscape (TAL) located at the foothills of Himalayas in North Western India, Buxa Tiger Reserve (BTR), and North East India. In TAL and BTR, we found a specific haplotype at high frequency, which was absent elsewhere, indicating a genetically distinct population in these regions. Within the TAL region, there is some evidence for genetic isolation of the tiger populations west of river Ganges, i.e., in the western part of Rajaji National Park (RNP). Although the river itself might not constitute a significant barrier for tigers, recent human-induced changes in habitat and degradation of the Motichur-Chilla Corridor connecting the two sides of the tiger habitat of RNP might effectively prevent genetic exchange. A cohesive population is observed for the rest of the TAL. Even the more eastern BTR belongs genetically to this unit, despite the present lack of a migration corridor between BTR and TAL. In spite of a close geographic proximity, Chitwan (Nepal) constitutes a tiger population genetically different from TAL. Moreover, it is observed that the North East India tiger populations are genetically different from TAL and BTR, as well as from the other Bengal tiger populations in India.
KW  - Bengal tiger
KW  - Population genetics
KW  - mtDNA haplotype
KW  - Terai Arc
Y1  - 2011
U6  - https://doi.org/10.1016/j.mambio.2010.10.005
SN  - 1616-5047
VL  - 76
IS  - 4
SP  - 484
EP  - 490
PB  - Elsevier
CY  - Jena
ER  - 
TY  - JOUR
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
JF  - BMC genomics
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.
Y1  - 2011
U6  - https://doi.org/10.1186/1471-2164-12-35
SN  - 1471-2164
VL  - 12
IS  - 2
PB  - BioMed Central
CY  - London
ER  - 
TY  - GEN
A1  - Pokorny, Ina
A1  - Sharma, Reeta
A1  - Goyal, Surendra Prakash
A1  - Mishra, Sudanshu
A1  - Tiedemann, Ralph
T1  - MHC class I and MHC class II DRB gene variability in wild and captive Bengal tigers (Panthera tigris tigris) (vol 10, pg 667, 2010)
T2  - Immunogenetics
Y1  - 2011
U6  - https://doi.org/10.1007/s00251-010-0496-2
SN  - 0093-7711
VL  - 63
IS  - 2
SP  - 121
EP  - 121
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Pavesi, Laura
A1  - De Matthaeis, Elvira
A1  - Tiedemann, Ralph
A1  - Ketmaier, Valerio
T1  - Temporal population genetics and COI phylogeography of the sandhopper macarorchestia remyi (Amphipoda: Talitridae)
JF  - Zoological studies
N2  - Laura Pavesi, Elvira De Matthaeis, Ralph Tiedemann, and Valerio Ketmaier (2011) Temporal population genetics and COI phylogeography of the sandhopper Macarorchestia remyi (Amphipoda: Talitridae). Zoological Studies 50(2): 220-229. In this study we assessed levels of genetic divergence and variability in 208 individuals of the supralittoral sandhopper Macarorchestia remyi, a species strictly associated with rotted wood stranded on sand beaches, by analyzing sequence polymorphisms in a fragment of the mitochondrial DNA (mtDNA) gene coding cytochrome oxidase subunit I (COI). The geographical distribution and ecology of the species are poorly known. The study includes 1 Tyrrhenian and 2 Adriatic populations sampled along the Italian peninsula plus a single individual found on Corfu Is. (Greece). The Tyrrhenian population was sampled monthly for 1 yr. Genetic data revealed a deep phylogeographic break between the Tyrrhenian and Adriatic populations with no shared haplotypes. The single individual collected on Corfu Is. carried the most common haplotype found in the Tyrrhenian population. A mismatch analysis could not reject the hypothesis of a sudden demographic expansion in almost all but 2 monthly samples. When compared to previous genetic data centered on a variety of Mediterranean talitrids, our results place M. remyi among those species with profound intraspecific divergence (sandhoppers) and dissimilar from beachfleas, which generally display little population genetic structuring.
KW  - Macarorchestia remyi
KW  - Talitridae
KW  - Cytochrome oxidase I
KW  - Population genetics
Y1  - 2011
SN  - 1021-5506
VL  - 50
IS  - 2
SP  - 220
EP  - 229
PB  - Institute of Zoology, Academia Sinica
CY  - Taipei
ER  - 
TY  - JOUR
A1  - Stoof-Leichsenring, Kathleen Rosemarie
A1  - Junginger, Annett
A1  - Olaka, Lydia A.
A1  - Tiedemann, Ralph
A1  - Trauth, Martin H.
T1  - Environmental variability in Lake Naivasha, Kenya, over the last two centuries
JF  - Journal of paleolimnolog
N2  - Lake Naivasha, Kenya, is one of a number of freshwater lakes in the East African Rift System. Since the beginning of the twentieth century, it has experienced greater anthropogenic influence as a result of increasingly intensive farming of coffee, tea, flowers, and other horticultural crops within its catchment. The water-level history of Lake Naivasha over the past 200 years was derived from a combination of instrumental records and sediment data. In this study, we analysed diatoms in a lake sediment core to infer past lacustrine conductivity and total phosphorus concentrations. We also measured total nitrogen and carbon concentrations in the sediments. Core chronology was established by (210)Pb dating and covered a similar to 186-year history of natural (climatic) and human-induced environmental changes. Three stratigraphic zones in the core were identified using diatom assemblages. There was a change from littoral/epiphytic diatoms such as Gomphonema gracile and Cymbella muelleri, which occurred during a prolonged dry period from ca. 1820 to 1896 AD, through a transition period, to the present planktonic Aulacoseira sp. that favors nutrient-rich waters. This marked change in the diatom assemblage was caused by climate change, and later a strong anthropogenic overprint on the lake system. Increases in sediment accumulation rates since 1928, from 0.01 to 0.08 g cm(-2) year(-1) correlate with an increase in diatom-inferred total phosphorus concentrations since the beginning of the twentieth century. The increase in phosphorus accumulation suggests increasing eutrophication of freshwater Lake Naivasha. This study identified two major periods in the lake's history: (1) the period from 1820 to 1950 AD, during which the lake was affected mainly by natural climate variations, and (2) the period since 1950, during which the effects of anthropogenic activity overprinted those of natural climate variation.
KW  - Lake sediments
KW  - Diatoms
KW  - Conductivity
KW  - Lake Naivasha
KW  - Human impact
KW  - Eutrophication
Y1  - 2011
U6  - https://doi.org/10.1007/s10933-011-9502-4
SN  - 0921-2728
VL  - 45
IS  - 3
SP  - 353
EP  - 367
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Struck, Torsten H.
A1  - Paul, Christiane
A1  - Hill, Natascha
A1  - Hartmann, Stefanie
A1  - Hoesel, Christoph
A1  - Kube, Michael
A1  - Lieb, Bernhard
A1  - Meyer, Achim
A1  - Tiedemann, Ralph
A1  - Purschke, Guenter
A1  - Bleidorn, Christoph
T1  - Phylogenomic analyses unravel annelid evolution
JF  - Nature : the international weekly journal of science
N2  - Annelida, the ringed worms, is a highly diverse animal phylum that includes more than 15,000 described species and constitutes the dominant benthic macrofauna from the intertidal zone down to the deep sea. A robust annelid phylogeny would shape our understanding of animal body-plan evolution and shed light on the bilaterian ground pattern. Traditionally, Annelida has been split into two major groups: Clitellata (earthworms and leeches) and polychaetes (bristle worms), but recent evidence suggests that other taxa that were once considered to be separate phyla (Sipuncula, Echiura and Siboglinidae (also known as Pogonophora)) should be included in Annelida(1-4). However, the deep-level evolutionary relationships of Annelida are still poorly understood, and a robust reconstruction of annelid evolutionary history is needed. Here we show that phylogenomic analyses of 34 annelid taxa, using 47,953 amino acid positions, recovered a well-supported phylogeny with strong support for major splits. Our results recover chaetopterids, myzostomids and sipunculids in the basal part of the tree, although the position of Myzostomida remains uncertain owing to its long branch. The remaining taxa are split into two clades: Errantia (which includes the model annelid Platynereis), and Sedentaria (which includes Clitellata). Ancestral character trait reconstructions indicate that these clades show adaptation to either an errant or a sedentary lifestyle, with alteration of accompanying morphological traits such as peristaltic movement, parapodia and sensory perception. Finally, life history characters in Annelida seem to be phylogenetically informative.
Y1  - 2011
U6  - https://doi.org/10.1038/nature09864
SN  - 0028-0836
VL  - 471
IS  - 7336
SP  - 95
EP  - U113
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Schwarte, Sandra
A1  - Tiedemann, Ralph
T1  - A Gene Duplication/Loss Event in the Ribulose-1,5-Bisphosphate-Carboxylase/Oxygenase (Rubisco) Small Subunit Gene Family among Accessions of Arabidopsis thaliana
JF  - Molecular biology and evolution
N2  - Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase; EC 4.1.1.39), the most abundant protein in nature, catalyzes the assimilation of CO(2) (worldwide about 10(11) t each year) by carboxylation of ribulose-1,5-bisphosphate. It is a hexadecamer consisting of eight large and eight small subunits. Although the Rubisco large subunit (rbcL) is encoded by a single gene on the multicopy chloroplast genome, the Rubisco small subunits (rbcS) are encoded by a family of nuclear genes. In Arabidopsis thaliana, the rbcS gene family comprises four members, that is, rbcS-1a, rbcS-1b, rbcS-2b, and rbcS-3b. We sequenced all Rubisco genes in 26 worldwide distributed A. thaliana accessions. In three of these accessions, we detected a gene duplication/loss event, where rbcS-1b was lost and substituted by a duplicate of rbcS-2b (called rbcS-2b*). By screening 74 additional accessions using a specific polymerase chain reaction assay, we detected five additional accessions with this duplication/loss event. In summary, we found the gene duplication/loss in 8 of 100 A. thaliana accessions, namely, Bch, Bu, Bur, Cvi, Fei, Lm, Sha, and Sorbo. We sequenced an about 1-kb promoter region for all Rubisco genes as well. This analysis revealed that the gene duplication/loss event was associated with promoter alterations (two insertions of 450 and 850 bp, one deletion of 730 bp) in rbcS-2b and a promoter deletion (2.3 kb) in rbcS-2b* in all eight affected accessions. The substitution of rbcS-1b by a duplicate of rbcS-2b (i.e., rbcS-2b*) might be caused by gene conversion. All four Rubisco genes evolve under purifying selection, as expected for central genes of the highly conserved photosystem of green plants. We inferred a single positive selected site, a tyrosine to aspartic acid substitution at position 72 in rbcS-1b. Exactly the same substitution compromises carboxylase activity in the cyanobacterium Anacystis nidulans. In A. thaliana, this substitution is associated with an inferred recombination. Functional implications of the substitution remain to be evaluated.
KW  - Arabidopsis thaliana
KW  - Arabidopsis lyrata
KW  - Rubisco
KW  - gene duplication
KW  - positive selection
Y1  - 2011
U6  - https://doi.org/10.1093/molbev/msr008
SN  - 0737-4038
VL  - 28
IS  - 6
SP  - 1861
EP  - 1876
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Tiedemann, Ralph
A1  - Paulus, Kirsten B.
A1  - Havenstein, Katja
A1  - Thorstensen, Sverrir
A1  - Petersen, Aevar
A1  - Lyngs, Peter
A1  - Milinkovitch, Michel C.
T1  - Alien eggs in duck nests brood parasitism or a help from Grandma?
JF  - Molecular ecology
N2  - Intraspecific brood parasitism (IBP) is a remarkable phenomenon by which parasitic females can increase their reproductive output by laying eggs in conspecific females' nests in addition to incubating eggs in their own nest. Kin selection could explain the tolerance, or even the selective advantage, of IBP, but different models of IBP based on game theory yield contradicting predictions. Our analyses of seven polymorphic autosomal microsatellites in two eider duck colonies indicate that relatedness between host and parasitizing females is significantly higher than the background relatedness within the colony. This result is unlikely to be a by-product of relatives nesting in close vicinity, as nest distance and genetic identity are not correlated. For eider females that had been ring-marked during the decades prior to our study, our analyses indicate that (i) the average age of parasitized females is higher than the age of nonparasitized females, (ii) the percentage of nests with alien eggs increases with the age of nesting females, (iii) the level of IBP increases with the host females' age, and (iv) the number of own eggs in the nest of parasitized females significantly decreases with age. IBP may allow those older females unable to produce as many eggs as they can incubate to gain indirect fitness without impairing their direct fitness: genetically related females specialize in their energy allocation, with young females producing more eggs than they can incubate and entrusting these to their older relatives. Intraspecific brood parasitism in ducks may constitute cooperation among generations of closely related females.
KW  - eider duck
KW  - indirect fitness
KW  - intraspecific brood parasitism
KW  - microsatellites
KW  - relatedness
KW  - Somateria mollissima
Y1  - 2011
U6  - https://doi.org/10.1111/j.1365-294X.2011.05158.x
SN  - 0962-1083
VL  - 20
IS  - 15
SP  - 3237
EP  - 3250
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Wiesner, Kerstin R.
A1  - Loxdale, Hugh D.
A1  - Köhler, Günter
A1  - Schneider, Anja R. R.
A1  - Tiedemann, Ralph
A1  - Weisser, Wolfgang W.
T1  - Patterns of local and regional genetic structuring in the meadow grasshopper, Chorthippus parallelus (Orthoptera: Acrididae), in Central Germany revealed using microsatellite markers
JF  - Biological journal of the Linnean Society : a journal of evolution
N2  - The meadow grasshopper, Chorthippus parallelus (Zetterstedt), is common and widespread in Central Europe, with a low dispersal range per generation. A population study in Central Germany (Frankenwald and Thuringer Schiefergebirge) showed strong interpopulation differences in abundance and individual fitness. We examined genetic variability using microsatellite markers within and between 22 populations in a short-to long-distance sampling (19 populations, Frankenwald, Schiefergebirge, as well as a southern transect), and in the Erzgebirge region (three populations), with the latter aiming to check for effects as a result of historical forest cover. Of the 671 C. parallelus captured, none was macropterous (functionally winged). All populations showed a high level of expected and observed heterozygosity (mean 0.80-0.90 and 0.60-0.75, respectively), whereas there was evidence of inbreeding (F(IS) values all positive). Allelic richness for all locus-population combinations was high (mean 9.3-11.2), whereas alleles per locus ranged from 15-62. At a local level, genic and genotypic differences were significant. Pairwise F(ST) values were in the range 0.00-0.04, indicating little interpopulation genetic differentiation. Similarly, the calculated gene flow was very high, based on the respective F(ST) (19.5) and using private alleles (7.7). A Neighbour-joining tree using Nei's D(A) and principal coordinate analysis separated two populations that were collected in the Erzgebirge region. Populations from this region may have escaped the effects of the historical forest cover. The visualization of the spatial arrangement of genotypes revealed one geographical barrier to gene flow in the short-distance sampling.
KW  - adaptation
KW  - gene flow
KW  - diversity
KW  - landscape structure
KW  - wing polyphenism
Y1  - 2011
U6  - https://doi.org/10.1111/j.1095-8312.2011.01698.x
SN  - 0024-4066
VL  - 103
IS  - 4
SP  - 875
EP  - 890
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Bonizzoni, Mariangela
A1  - Bourjea, Jerome
A1  - Chen, Bin
A1  - Crain, B. J.
A1  - Cui, Liwang
A1  - Fiorentino, V.
A1  - Hartmann, Stefanie
A1  - Hendricks, S.
A1  - Ketmaier, Valerio
A1  - Ma, Xiaoguang
A1  - Muths, Delphine
A1  - Pavesi, Laura
A1  - Pfautsch, Simone
A1  - Rieger, M. A.
A1  - Santonastaso, T.
A1  - Sattabongkot, Jetsumon
A1  - Taron, C. H.
A1  - Taron, D. J.
A1  - Tiedemann, Ralph
A1  - Yan, Guiyun
A1  - Zheng, Bin
A1  - Zhong, Daibin
T1  - Permanent genetic resources added to molecular ecology resources database 1 April 2011-31 May 2011
JF  - Molecular ecology resources
N2  - This article documents the addition of 92 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Anopheles minimus, An. sinensis, An. dirus, Calephelis mutica, Lutjanus kasmira, Murella muralis and Orchestia montagui. These loci were cross-tested on the following species: Calephelis arizonensi, Calephelis borealis, Calephelis nemesis, Calephelis virginiensis and Lutjanus bengalensis.
Y1  - 2011
U6  - https://doi.org/10.1111/j.1755-0998.2011.03046.x
SN  - 1755-098X
VL  - 11
IS  - 5
SP  - 935
EP  - 936
PB  - Wiley-Blackwell
CY  - Malden
ER  -