@article{FiorentinoManganelliGiustietal.2013, author = {Fiorentino, V. and Manganelli, Giuseppe and Giusti, Folco and Tiedemann, Ralph and Ketmaier, Valerino}, title = {A question of time the land snail Murella muralis (Gastropoda: Pulmonata) reveals constraints on past ecological speciation}, series = {Molecular ecology}, volume = {22}, journal = {Molecular ecology}, number = {1}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0962-1083}, doi = {10.1111/mec.12107}, pages = {170 -- 186}, year = {2013}, abstract = {The lively debate about speciation currently focuses on the relative importance of factors driving population differentiation. While many studies are increasingly producing results on the importance of selection, little is known about the interaction between drift and selection. Moreover, there is still little knowledge on the spatial-temporal scales at which speciation occurs, that is, arrangement of habitat patches, abruptness of habitat transitions, climate and habitat changes interacting with selective forces. To investigate these questions, we quantified variation on a fine geographical scale analysing morphological (shell) and genetic data sets coupled with environmental data in the land snail Murella muralis, endemic to the Mediterranean island of Sicily. Analysis of a fragment of the mitochondrial DNA cytochrome oxidase I gene (COI) and eight nuclear microsatellite loci showed that genetic variation is highly structured at a very fine spatial scale by local palaeogeographical events and historical population dynamics. Molecular clock estimates, calibrated here specifically for Tyrrhenian land snails, provided a framework of palaeogeographical events responsible for the observed geographical variations and migration routes. Finally, we showed for the first time well-documented lines of evidence of selection in the past, which explains divergence of land snail shell shapes. We suggest that time and palaeogeographical history acted as constraints in the progress along the ecological speciation continuum. Our study shows that testing for correlation among palaeogeography, morphology and genetic data on a fine geographical scale provides information fundamental for a detailed understanding of ecological speciation processes.}, language = {en} } @article{SpikesRodriguezSilvaBennettetal.2021, author = {Spikes, Montrai and Rodr{\´i}guez-Silva, Rodet and Bennett, Kerri-Ann and Br{\"a}ger, Stefan and Josaphat, James and Torres-Pineda, Patricia and Ernst, Anja and Havenstein, Katja and Schlupp, Ingo and Tiedemann, Ralph}, title = {A phylogeny of the genus Limia (Teleostei: Poeciliidae) suggests a single-lake radiation nested in a Caribbean-wide allopatric speciation scenario}, series = {BMC Research Notes}, volume = {14}, journal = {BMC Research Notes}, publisher = {BMC Research Notes / Biomed Central}, address = {London}, issn = {1756-0500}, doi = {10.1186/s13104-021-05843-x}, pages = {1 -- 8}, year = {2021}, abstract = {Objective The Caribbean is an important global biodiversity hotspot. Adaptive radiations there lead to many speciation events within a limited period and hence are particularly prominent biodiversity generators. A prime example are freshwater fish of the genus Limia, endemic to the Greater Antilles. Within Hispaniola, nine species have been described from a single isolated site, Lake Mirago{\^a}ne, pointing towards extraordinary sympatric speciation. This study examines the evolutionary history of the Limia species in Lake Mirago{\^a}ne, relative to their congeners throughout the Caribbean. Results For 12 Limia species, we obtained almost complete sequences of the mitochondrial cytochrome b gene, a well-established marker for lower-level taxonomic relationships. We included sequences of six further Limia species from GenBank (total N  = 18 species). Our phylogenies are in concordance with other published phylogenies of Limia. There is strong support that the species found in Lake Mirago{\^a}ne in Haiti are monophyletic, confirming a recent local radiation. Within Lake Mirago{\^a}ne, speciation is likely extremely recent, leading to incomplete lineage sorting in the mtDNA. Future studies using multiple unlinked genetic markers are needed to disentangle the relationships within the Lake Mirago{\^a}ne clade.}, language = {en} } @article{BleidornLanterbecqEeckhautetal.2009, author = {Bleidorn, Christoph and Lanterbecq, Deborah and Eeckhaut, Igor and Tiedemann, Ralph}, title = {A PCR survey of Hox genes in the myzostomid Myzostoma cirriferum}, issn = {0949-944X}, doi = {10.1007/s00427-009-0282-z}, year = {2009}, abstract = {Using degenerate primers, we were able to identify seven Hox genes for the myzostomid Myzostoma cirriferum. The recovered fragments belong to anterior class (Mci_lab, Mci_pb), central class (Mci_Dfd, Mci_Lox5, Mci_Antp, Mci_Lox4), and posterior class (Mci_Post2) paralog groups. Orthology assignment was verified by phylogenetic analyses and presence of diagnostic regions in the homeodomain as well as flanking regions. The presence of Lox5, Lox4, and Post2 supports the inclusion of Myzostomida within Lophotrochozoa. We found signature residues within flanking regions of Lox5, which are also found in annelids, but not in Platyhelminthes. As such the available Hox genes data of myzostomids support an annelid relationship.}, language = {en} } @article{SchwarteTiedemann2011, author = {Schwarte, Sandra and Tiedemann, Ralph}, title = {A Gene Duplication/Loss Event in the Ribulose-1,5-Bisphosphate-Carboxylase/Oxygenase (Rubisco) Small Subunit Gene Family among Accessions of Arabidopsis thaliana}, series = {Molecular biology and evolution}, volume = {28}, journal = {Molecular biology and evolution}, number = {6}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0737-4038}, doi = {10.1093/molbev/msr008}, pages = {1861 -- 1876}, year = {2011}, abstract = {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.}, language = {en} } @article{ZiegeHennigeSchulzMueckschetal.2012, author = {Ziege, Madlen and Hennige-Schulz, Carmen and Muecksch, Frauke and Bierbach, David and Tiedemann, Ralph and Streit, Bruno and Plath, Martin}, title = {A comparison of two methods to assess audience-induced changes in male mate choice}, series = {Current zoology}, volume = {58}, journal = {Current zoology}, number = {1}, publisher = {Current Zoology}, address = {Beijing}, issn = {1674-5507}, pages = {84 -- 94}, year = {2012}, abstract = {Multidirectional communicative interactions in social networks can have a profound effect on mate choice behavior. Male Atlantic molly Poecilia mexicana exhibit weaker mating preferences when an audience male is presented. This could be a male strategy to reduce sperm competition risk: interacting more equally with different females may be advantageous because rivals might copy mate choice decisions. In line with this hypothesis, a previous study found males to show a strong audience effect when being observed while exercising mate choice, but not when the rival was presented only before the choice tests. Audience effects on mate choice decisions have been quantified in poeciliid fishes using association preference designs, but it remains unknown if patterns found from measuring association times translate into actual mating behavior. Thus, we created five audience treatments simulating different forms of perceived sperm competition risk and determined focal males' mating preferences by scoring pre-mating (nipping) and mating behavior (gonopodial thrusting). Nipping did not reflect the pattern that was found when association preferences were measured, while a very similar pattern was uncovered in thrusting behavior. The strongest response was observed when the audience could eavesdrop on the focal male's behavior. A reduction in the strength of focal males' preferences was also seen after the rival male had an opportunity to mate with the focal male's preferred mate. In comparison, the reduction of mating preferences in response to an audience was greater when measuring association times than actual mating behavior. While measuring direct sexual interactions between the focal male and both stimulus females not only the male's motivational state is reflected but also females' behavior such as avoidance of male sexual harassment.}, language = {en} } @article{StoofLeichsenringBernhardtPestryakovaetal.2014, author = {Stoof-Leichsenring, Kathleen Rosemarie and Bernhardt, Nadine and Pestryakova, Luidmila Agafyevna and Epp, Laura Saskia and Herzschuh, Ulrike and Tiedemann, Ralph}, title = {A combined paleolimnological/genetic analysis of diatoms reveals divergent evolutionary lineages of Staurosira and Staurosirella (Bacillariophyta) in Siberian lake sediments along a latitudinal transect}, series = {Journal of paleolimnolog}, volume = {52}, journal = {Journal of paleolimnolog}, number = {1-2}, publisher = {Springer}, address = {Dordrecht}, issn = {0921-2728}, doi = {10.1007/s10933-014-9779-1}, pages = {77 -- 93}, year = {2014}, abstract = {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.}, language = {en} }