TY - JOUR A1 - Kobel-Höller, Konstanze A1 - Gley, Kevin A1 - Jochinke, Janina A1 - Heider, Kristina A1 - Fritsch, Verena Nadin A1 - Ha Viet Duc Nguyen, A1 - Lischke, Timo A1 - Radek, Renate A1 - Baumgrass, Ria A1 - Mutzel, Rupert A1 - Thewes, Sascha T1 - Calcineurin Silencing in Dictyostelium discoideum Leads to Cellular Alterations Affecting Mitochondria, Gene Expression, and Oxidative Stress Response JF - Protist N2 - Calcineurin is involved in development and cell differentiation of the social amoeba Dictyostelium discoideum. However, since knockouts of the calcineurin-encoding genes are not possible in D. discoideum it is assumed that the phosphatase also plays a crucial role during vegetative growth of the amoebae. Therefore, we investigated the role of calcineurin during vegetative growth in D. discoideum. RNAi-silenced calcineurin mutants showed cellular alterations with an abnormal morphology of mitochondria and had increased content of mitochondrial DNA (mtDNA). In contrast, mitochondria showed no substantial functional impairment. Calcineurin-silencing led to altered expression of calcium-regulated genes as well as mitochondrially-encoded genes. Furthermore, genes related to oxidative stress were higher expressed in the mutants, which correlated to an increased resistance towards reactive oxygen species (ROS). Most of the changes observed during vegetative growth were not seen after starvation of the calcineurin mutants. We show that impairment of calcineurin led to many subtle, but in the sum crucial cellular alterations in vegetative D. discoideum cells. As these alterations were not observed after starvation we propose a dual role for calcineurin during growth and development. Our results imply that calcineurin is one player in the mutual interplay between mitochondria and ROS during vegetative growth. KW - mtDNA KW - mitochondrial remodelling KW - calcium KW - oxidative stress KW - phototaxis Y1 - 2018 U6 - https://doi.org/10.1016/j.protis.2018.04.004 SN - 1434-4610 VL - 169 IS - 4 SP - 584 EP - 602 PB - Elsevier GMBH CY - München ER - TY - JOUR A1 - Paijmans, Johanna L. A. A1 - Barlow, Axel A1 - Förster, Daniel W. A1 - Henneberger, Kirstin A1 - Meyer, Matthias A1 - Nickel, Birgit A1 - Nagel, Doris A1 - Worsøe Havmøller, Rasmus A1 - Baryshnikov, Gennady F. A1 - Joger, Ulrich A1 - Rosendahl, Wilfried A1 - Hofreiter, Michael T1 - Historical biogeography of the leopard (Panthera pardus) and its extinct Eurasian populations JF - BMC Evolutionary Biology N2 - Background Resolving the historical biogeography of the leopard (Panthera pardus) is a complex issue, because patterns inferred from fossils and from molecular data lack congruence. Fossil evidence supports an African origin, and suggests that leopards were already present in Eurasia during the Early Pleistocene. Analysis of DNA sequences however, suggests a more recent, Middle Pleistocene shared ancestry of Asian and African leopards. These contrasting patterns led researchers to propose a two-stage hypothesis of leopard dispersal out of Africa: an initial Early Pleistocene colonisation of Asia and a subsequent replacement by a second colonisation wave during the Middle Pleistocene. The status of Late Pleistocene European leopards within this scenario is unclear: were these populations remnants of the first dispersal, or do the last surviving European leopards share more recent ancestry with their African counterparts? Results In this study, we generate and analyse mitogenome sequences from historical samples that span the entire modern leopard distribution, as well as from Late Pleistocene remains. We find a deep bifurcation between African and Eurasian mitochondrial lineages (~ 710 Ka), with the European ancient samples as sister to all Asian lineages (~ 483 Ka). The modern and historical mainland Asian lineages share a relatively recent common ancestor (~ 122 Ka), and we find one Javan sample nested within these. Conclusions The phylogenetic placement of the ancient European leopard as sister group to Asian leopards suggests that these populations originate from the same out-of-Africa dispersal which founded the Asian lineages. The coalescence time found for the mitochondrial lineages aligns well with the earliest undisputed fossils in Eurasia, and thus encourages a re-evaluation of the identification of the much older putative leopard fossils from the region. The relatively recent ancestry of all mainland Asian leopard lineages suggests that these populations underwent a severe population bottleneck during the Pleistocene. Finally, although only based on a single sample, the unexpected phylogenetic placement of the Javan leopard could be interpreted as evidence for exchange of mitochondrial lineages between Java and mainland Asia, calling for further investigation into the evolutionary history of this subspecies. KW - Ancient DNA KW - Hybridisation capture KW - Leopards KW - Mitochondrial genomes KW - Mitogenomes KW - mtDNA KW - Palaeogenetics KW - Panthera pardus Y1 - 2018 U6 - https://doi.org/10.1186/s12862-018-1268-0 SN - 1471-2148 VL - 18 IS - 156 PB - BioMed Central und Springer CY - London, Berlin und Heidelberg ER -