Tracing the First Steps of American Sturgeon Pioneers in Europe

Background: A Baltic population of Atlantic sturgeon was founded ~1,200 years ago by migrantsfrom North America, but after centuries of persistence, the population was extirpated in the 1960s,mainly as a result of over-harvest and habitat alterations. As there are four genetically distinctgroups of Atlantic sturgeon inhabiting North American rivers today, we investigated the geneticprovenance of the historic Baltic population by ancient DNA analyses using mitochondrial andnuclear markers.Results: The phylogeographic signal obtained from multilocus microsatellite DNA genotypes andmitochondrial DNA control region haplotypes, when compared to existing baseline datasets fromextant populations, allowed for the identification of the region-of-origin of the North AmericanAtlantic sturgeon founders. Moreover, statistical and simulation analyses of the multilocusgenotypes allowed for the calculation of the effective number of individuals that originally foundedthe European population of Atlantic sturgeon. Our findings suggest that the Baltic population of A.oxyrinchus descended from a relatively small number of founders originating from the northernextent of the species\u27 range in North America.Conclusion: These results demonstrate that the most northerly distributed North American A.oxyrinchus colonized the Baltic Sea ~1,200 years ago, suggesting that Canadian specimens should bethe primary source of broodstock used for restoration in Baltic rivers. This study illustrates thegreat potential of patterns obtained from ancient DNA to identify population-of-origin toinvestigate historic genotype structure of extinct populations

Deglacial patterns of South Pacific overturning inferred from 231Pa and 230Th

The millennial‐scale variability of the Atlantic Meridional Overturning Circulation (AMOC) is well documented for the last glacial termination and beyond. Despite its importance for the climate system, the evolution of the South Pacific overturning circulation (SPOC) is by far less well understood. A recently published study highlights the potential applicability of the 231Pa/230Th‐proxy in the Pacific. Here, we present five sedimentary down‐core profiles of 231Pa/230Th‐ratios measured on a depth transect from the Pacific sector of the Southern Ocean to test this hypothesis using downcore records. Our data are consistent with an increase in SPOC as early as 20 ka that peaked during Heinrich Stadial 1. The timing indicates that the SPOC did not simply react to AMOC changes via the bipolar seesaw but were triggered via Southern Hemisphere processes

Herkunftsvergleich Karpfen: Vergleich der Eignung verschiedener Gebrauchskarpfenbestände (Cyprinus carpio L.) zur Teichaufzucht unter Verwendung des „Communal testings“ und Zuordnung von Herkünften über Mikrosatellitenmarkeranalysen

Die Leistung sächsischer Teichkarpfen wurde mit genetisch und räumlich weit entfernten europäischen Zuchtlinien verglichen. Zwischen den ausgewählten Herkünften des Karpfens konnten deutliche Leistungsunterschiede festgestellt werden. Es gab jedoch keine Herkunft, die in allen geprüften Belangen den anderen deutlich überlegen war. Herausragend positive Ergebnisse hinsichtlich ihrer Eignung für die Teichaufzucht erreichten Schuppenkarpfen einer tschechischen Herkunft. Im Ergebnis der Untersuchungen werden Empfehlungen für die praktische Zuchtarbeit in Karpfenvermehrungsbetrieben gegeben

Function-structure approach reveals novel insights on the interplay of Immunoglobulin G 1 proteoforms and Fc gamma receptor IIa allotypes

Human Fc gamma receptor IIa (FcγRIIa) or CD32a has two major allotypes with a single amino acid difference at position 131 (histidine or arginine). Differences in FcγRIIa allotypes are known to impact immunological responses such as the clinical outcome of therapeutic monoclonal antibodies (mAbs). FcγRIIa is involved in antibody-dependent cellular phagocytosis (ADCP), which is an important contributor to the mechanism-of-action of mAbs by driving phagocytic clearance of cancer cells. Hence, understanding the impact of individual mAb proteoforms on the binding to FcγRIIa, and its different allotypes, is crucial for defining meaningful critical quality attributes (CQAs). Here, we report a function-structure based approach guided by novel FcγRIIa affinity chromatography-mass spectrometry (AC-MS) assays to assess individual IgG1 proteoforms. This allowed to unravel allotype-specific differences of IgG1 proteoforms on FcγRIIa binding. FcγRIIa AC-MS confirmed and refined structure-function relationships of IgG1 glycoform interactions. For example, the positive impact of afucosylation was higher than galactosylation for FcγRIIa Arg compared to FcγRIIa His. Moreover, we observed FcγRIIa allotype-opposing and IgG1 proteoform integrity-dependent differences in the binding response of stress-induced IgG1 proteoforms comprising asparagine 325 deamidation. The FcγRIIa-allotype dependent binding differences resolved by AC-MS were in line with functional ADCP-surrogate bioassay models. The molecular basis of the observed allotype specificity and proteoform selectivity upon asparagine 325 deamidation was elucidated using molecular dynamics. The observed differences were attributed to the contributions of an inter-molecular salt bridge between IgG1 and FcγRIIa Arg and the contribution of an intra-molecular hydrophobic pocket in IgG1. Our work highlights the unprecedented structural and functional resolution of AC-MS approaches along with predictive biological significance of observed affinity differences within relevant cell-based methods. This makes FcγRIIa AC-MS an invaluable tool to streamline the CQA assessment of therapeutic mAbs

The Evolutionary and Phylogeographic History of Woolly Mammoths: A Comprehensive Mitogenomic Analysis

Near the end of the Pleistocene epoch, populations of the woolly mammoth (Mammuthus primigenius) were distributed across parts of three continents, from western Europe and northern Asia through Beringia to the Atlantic seaboard of North America. Nonetheless, questions about the connectivity and temporal continuity of mammoth populations and species remain unanswered. We use a combination of targeted enrichment and high-throughput sequencing to assemble and interpret a data set of 143 mammoth mitochondrial genomes, sampled from fossils recovered from across their Holarctic range. Our dataset includes 54 previously unpublished mitochondrial genomes and significantly increases the coverage of the Eurasian range of the species. The resulting global phylogeny confirms that the Late Pleistocene mammoth population comprised three distinct mitochondrial lineages that began to diverge ∼1.0-2.0 million years ago (Ma). We also find that mammoth mitochondrial lineages were strongly geographically partitioned throughout the Pleistocene. In combination, our genetic results and the pattern of morphological variation in time and space suggest that male-mediated gene flow, rather than large-scale dispersals, was important in the Pleistocene evolutionary history of mammoths

Down-core measurements of SiO2 for sediment core PS75/104-1

SiO2 measurements were conducted to analyze a potential impact on opal on our 231Pa/230Th ratios, that in turn were used to reconstruct past changes in South Pacific Overtruning Circulation. Opal measurements followed the method of Müller and Schneider 1993

Down-core measurements of 231Pa/230Th for sediment core PS75/100-4

The concentrations of sedimentary 231Pa, 238U, 230Th, and 232Th were jointly measured by isotope dilution in a co-operation between AWI and Heidelberg University with contributions from the GEOMAR Kiel and using mass spectrometers at the AWI (Element 2), Heidelberg (Element 2, Neptune, iCap) and Kiel (Neptune)

Down-core measurements of SiO2 for sediment core PS75/100-4

SiO2 measurements were conducted to analyze a potential impact on opal on our 231Pa/230Th ratios, that in turn were used to reconstruct past changes in South Pacific Overtruning Circulation. Opal measurements followed the method of Müller and Schneider 1993