@article{AlbertiGonzalezPaijmansetal.2018, author = {Alberti, Federica and Gonzalez, Javier and Paijmans, Johanna L. A. and Basler, Nikolas and Preick, Michaela and Henneberger, Kirstin and Trinks, Alexandra and Rabeder, Gernot and Conard, Nicholas J. and Muenzel, Susanne C. and Joger, Ulrich and Fritsch, Guido and Hildebrandt, Thomas and Hofreiter, Michael and Barlow, Axel}, title = {Optimized DNA sampling of ancient bones using Computed Tomography scans}, series = {Molecular ecology resources}, volume = {18}, journal = {Molecular ecology resources}, number = {6}, publisher = {Wiley}, address = {Hoboken}, issn = {1755-098X}, doi = {10.1111/1755-0998.12911}, pages = {1196 -- 1208}, year = {2018}, abstract = {The prevalence of contaminant microbial DNA in ancient bone samples represents the principal limiting factor for palaeogenomic studies, as it may comprise more than 99\% of DNA molecules obtained. Efforts to exclude or reduce this contaminant fraction have been numerous but also variable in their success. Here, we present a simple but highly effective method to increase the relative proportion of endogenous molecules obtained from ancient bones. Using computed tomography (CT) scanning, we identify the densest region of a bone as optimal for sampling. This approach accurately identifies the densest internal regions of petrous bones, which are known to be a source of high-purity ancient DNA. For ancient long bones, CT scans reveal a high-density outermost layer, which has been routinely removed and discarded prior to DNA extraction. For almost all long bones investigated, we find that targeted sampling of this outermost layer provides an increase in endogenous DNA content over that obtained from softer, trabecular bone. This targeted sampling can produce as much as 50-fold increase in the proportion of endogenous DNA, providing a directly proportional reduction in sequencing costs for shotgun sequencing experiments. The observed increases in endogenous DNA proportion are not associated with any reduction in absolute endogenous molecule recovery. Although sampling the outermost layer can result in higher levels of human contamination, some bones were found to have more contamination associated with the internal bone structures. Our method is highly consistent, reproducible and applicable across a wide range of bone types, ages and species. We predict that this discovery will greatly extend the potential to study ancient populations and species in the genomics era.}, language = {en} } @article{BarlowCahillHartmannetal.2018, author = {Barlow, Axel and Cahill, James A. and Hartmann, Stefanie and Theunert, Christoph and Xenikoudakis, Georgios and Gonzalez-Fortes, Gloria M. and Paijmans, Johanna L. A. and Rabeder, Gernot and Frischauf, Christine and Garcia-Vazquez, Ana and Murtskhvaladze, Marine and Saarma, Urmas and Anijalg, Peeter and Skrbinsek, Tomaz and Bertorelle, Giorgio and Gasparian, Boris and Bar-Oz, Guy and Pinhasi, Ron and Slatkin, Montgomery and Dalen, Love and Shapiro, Beth and Hofreiter, Michael}, title = {Partial genomic survival of cave bears in living brown bears}, series = {Nature Ecology \& Evolution}, volume = {2}, journal = {Nature Ecology \& Evolution}, number = {10}, publisher = {Nature Publ. Group}, address = {London}, issn = {2397-334X}, doi = {10.1038/s41559-018-0654-8}, pages = {1563 -- 1570}, year = {2018}, abstract = {Although many large mammal species went extinct at the end of the Pleistocene epoch, their DNA may persist due to past episodes of interspecies admixture. However, direct empirical evidence of the persistence of ancient alleles remains scarce. Here, we present multifold coverage genomic data from four Late Pleistocene cave bears (Ursus spelaeus complex) and show that cave bears hybridized with brown bears (Ursus arctos) during the Pleistocene. We develop an approach to assess both the directionality and relative timing of gene flow. We find that segments of cave bear DNA still persist in the genomes of living brown bears, with cave bears contributing 0.9 to 2.4\% of the genomes of all brown bears investigated. Our results show that even though extinction is typically considered as absolute, following admixture, fragments of the gene pool of extinct species can survive for tens of thousands of years in the genomes of extant recipient species.}, language = {en} } @misc{BarlowShengLaietal.2018, author = {Barlow, Axel and Sheng, Gui-Lian and Lai, Xu-Long and Hofreiter, Michael and Paijmans, Johanna L. A.}, title = {Once lost, twice found: Combined analysis of ancient giant panda sequences characterises extinct clade}, series = {Journal of biogeography}, volume = {46}, journal = {Journal of biogeography}, number = {1}, publisher = {Wiley}, address = {Hoboken}, issn = {0305-0270}, doi = {10.1111/jbi.13486}, pages = {251 -- 253}, year = {2018}, language = {en} } @article{PaijmansBarlowFoersteretal.2018, author = {Paijmans, Johanna L. A. and Barlow, Axel and F{\"o}rster, Daniel W. and Henneberger, Kirstin and Meyer, Matthias and Nickel, Birgit and Nagel, Doris and Wors{\o}e Havm{\o}ller, Rasmus and Baryshnikov, Gennady F. and Joger, Ulrich and Rosendahl, Wilfried and Hofreiter, Michael}, title = {Historical biogeography of the leopard (Panthera pardus) and its extinct Eurasian populations}, series = {BMC Evolutionary Biology}, volume = {18}, journal = {BMC Evolutionary Biology}, number = {156}, publisher = {BioMed Central und Springer}, address = {London, Berlin und Heidelberg}, issn = {1471-2148}, doi = {10.1186/s12862-018-1268-0}, pages = {12}, year = {2018}, abstract = {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.}, language = {en} } @misc{TaronLellBarlowetal.2018, author = {Taron, Ulrike H. and Lell, Moritz and Barlow, Axel and Paijmans, Johanna L. A.}, title = {Testing of Alignment Parameters for Ancient Samples}, series = {Genes}, journal = {Genes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-409683}, pages = {12}, year = {2018}, abstract = {High-throughput sequence data retrieved from ancient or other degraded samples has led to unprecedented insights into the evolutionary history of many species, but the analysis of such sequences also poses specific computational challenges. The most commonly used approach involves mapping sequence reads to a reference genome. However, this process becomes increasingly challenging with an elevated genetic distance between target and reference or with the presence of contaminant sequences with high sequence similarity to the target species. The evaluation and testing of mapping efficiency and stringency are thus paramount for the reliable identification and analysis of ancient sequences. In this paper, we present 'TAPAS', (Testing of Alignment Parameters for Ancient Samples), a computational tool that enables the systematic testing of mapping tools for ancient data by simulating sequence data reflecting the properties of an ancient dataset and performing test runs using the mapping software and parameter settings of interest. We showcase TAPAS by using it to assess and improve mapping strategy for a degraded sample from a banded linsang (Prionodon linsang), for which no closely related reference is currently available. This enables a 1.8-fold increase of the number of mapped reads without sacrificing mapping specificity. The increase of mapped reads effectively reduces the need for additional sequencing, thus making more economical use of time, resources, and sample material.}, language = {en} } @article{TaronLellBarlowetal.2018, author = {Taron, Ulrike H. and Lell, Moritz and Barlow, Axel and Paijmans, Johanna L. A.}, title = {Testing of Alignment Parameters for Ancient Samples}, series = {Genes}, volume = {9}, journal = {Genes}, number = {3}, publisher = {Molecular Diversity Preservation International}, address = {Basel}, issn = {2073-4425}, doi = {10.3390/genes9030157}, pages = {1 -- 12}, year = {2018}, abstract = {High-throughput sequence data retrieved from ancient or other degraded samples has led to unprecedented insights into the evolutionary history of many species, but the analysis of such sequences also poses specific computational challenges. The most commonly used approach involves mapping sequence reads to a reference genome. However, this process becomes increasingly challenging with an elevated genetic distance between target and reference or with the presence of contaminant sequences with high sequence similarity to the target species. The evaluation and testing of mapping efficiency and stringency are thus paramount for the reliable identification and analysis of ancient sequences. In this paper, we present 'TAPAS', (Testing of Alignment Parameters for Ancient Samples), a computational tool that enables the systematic testing of mapping tools for ancient data by simulating sequence data reflecting the properties of an ancient dataset and performing test runs using the mapping software and parameter settings of interest. We showcase TAPAS by using it to assess and improve mapping strategy for a degraded sample from a banded linsang (Prionodon linsang), for which no closely related reference is currently available. This enables a 1.8-fold increase of the number of mapped reads without sacrificing mapping specificity. The increase of mapped reads effectively reduces the need for additional sequencing, thus making more economical use of time, resources, and sample material.}, language = {en} } @article{TaronLellBarlowetal.2018, author = {Taron, Ulrike H. and Lell, Moritz and Barlow, Axel and Paijmans, Johanna L. A.}, title = {Testing of Alignment Parameters for Ancient Samples}, series = {Genese}, volume = {9}, journal = {Genese}, number = {3}, publisher = {MDPI}, address = {Basel}, issn = {2073-4425}, doi = {10.3390/genes9030157}, pages = {12}, year = {2018}, abstract = {High-throughput sequence data retrieved from ancient or other degraded samples has led to unprecedented insights into the evolutionary history of many species, but the analysis of such sequences also poses specific computational challenges. The most commonly used approach involves mapping sequence reads to a reference genome. However, this process becomes increasingly challenging with an elevated genetic distance between target and reference or with the presence of contaminant sequences with high sequence similarity to the target species. The evaluation and testing of mapping efficiency and stringency are thus paramount for the reliable identification and analysis of ancient sequences. In this paper, we present 'TAPAS', (Testing of Alignment Parameters for Ancient Samples), a computational tool that enables the systematic testing of mapping tools for ancient data by simulating sequence data reflecting the properties of an ancient dataset and performing test runs using the mapping software and parameter settings of interest. We showcase TAPAS by using it to assess and improve mapping strategy for a degraded sample from a banded linsang (Prionodon linsang), for which no closely related reference is currently available. This enables a 1.8-fold increase of the number of mapped reads without sacrificing mapping specificity. The increase of mapped reads effectively reduces the need for additional sequencing, thus making more economical use of time, resources, and sample material.}, language = {en} } @article{ThorpeBarlowSurgetGrobaetal.2018, author = {Thorpe, Roger and Barlow, Axel and Surget-Groba, Yann and Malhotra, Anita}, title = {Multilocus phylogeny, species age and biogeography of the Lesser Antillean anoles}, series = {Molecular phylogenetics and evolution}, volume = {127}, journal = {Molecular phylogenetics and evolution}, publisher = {Elsevier}, address = {San Diego}, issn = {1055-7903}, doi = {10.1016/j.ympev.2018.06.014}, pages = {682 -- 695}, year = {2018}, abstract = {Lesser Antillean anoles provide classic examples of island radiations. A detailed knowledge of their phylogeny and biogeography, in particular how the age of species relate to the ages of their respective islands and the age of their radiation, is essential to elucidate the tempo and mechanisms of these radiations. We conduct a large-scale phylogenetic and phylogeographic investigation of the Lesser Antillean anoles using multiple genetic markers and comprehensive geographic sampling of most species. The multilocus phylogeny gives the first well-supported reconstruction of the interspecific relationships, and the densely sampled phylogeography reveals a highly dynamic system, driven by overseas dispersal, with several alternative post-dispersal colonisation trajectories. These radiations currently occupy both the outer-older (Eocene to Miocene), and the inner-younger (< 8mybp), Lesser Antillean arcs. The origin of these radiations corresponds with the age of the ancient outer arc. However, the ages of extant species (compatible with the age of other small terrestrial amniotes) are much younger, about the age of the emergence of the younger arc, or less. The difference between the age of the radiation and the age of the extant species suggests substantial species turnover on older arc islands, most likely through competitive replacement. Although extant anoles are extremely speciose, this may represent only a fraction of their biodiversity over time. While paraphyly enables us to infer several recent colonization events, the absence of the younger arc islands and extant species at the earlier and middle stages of the radiation, does not allow the earlier inter-island colonization to be reliably inferred. Reproductive isolation in allopatry takes a very considerable time (in excess of 8my) and sympatry appears to occur only late in the radiation. The resolved multilocus phylogeny, and relative species age, raise difficulties for some earlier hypotheses regarding size evolution, and provide no evidence for within-island speciation.}, language = {en} } @misc{WestburyHartmannBarlowetal.2018, author = {Westbury, Michael V. and Hartmann, Stefanie and Barlow, Axel and Wiesel, Ingrid and Leo, Viyanna and Welch, Rebecca and Parker, Daniel M. and Sicks, Florian and Ludwig, Arne and Dalen, Love and Hofreiter, Michael}, title = {Extended and continuous decline in effective population size results in low genomic diversity in the world's rarest hyena species, the brown hyena}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {589}, issn = {1866-8372}, doi = {10.25932/publishup-41413}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414132}, pages = {13}, year = {2018}, abstract = {Hyenas (family Hyaenidae), as the sister group to cats (family Felidae), represent a deeply diverging branch within the cat-like carnivores (Feliformia). With an estimated population size of <10,000 individuals worldwide, the brown hyena (Parahyaena brunnea) represents the rarest of the four extant hyena species and has been listed as Near Threatened by the IUCN. Here, we report a high-coverage genome from a captive bred brown hyena and both mitochondrial and low-coverage nuclear genomes of 14 wild-caught brown hyena individuals from across southern Africa. We find that brown hyena harbor extremely low genetic diversity on both the mitochondrial and nuclear level, most likely resulting from a continuous and ongoing decline in effective population size that started similar to 1 Ma and dramatically accelerated towards the end of the Pleistocene. Despite the strikingly low genetic diversity, we find no evidence of inbreeding within the captive bred individual and reveal phylogeographic structure, suggesting the existence of several potential subpopulations within the species.}, language = {en} } @article{WestburyHartmannBarlowetal.2018, author = {Westbury, Michael V. and Hartmann, Stefanie and Barlow, Axel and Wiesel, Ingrid and Leo, Viyanna and Welch, Rebecca and Parker, Daniel M. and Sicks, Florian and Ludwig, Arne and Dalen, Love and Hofreiter, Michael}, title = {Extended and continuous decline in effective population size results in low genomic diversity in the world's rarest hyena species, the brown hyena}, series = {Molecular biology and evolution}, volume = {35}, journal = {Molecular biology and evolution}, number = {5}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0737-4038}, doi = {10.1093/molbev/msy037}, pages = {1225 -- 1237}, year = {2018}, abstract = {Hyenas (family Hyaenidae), as the sister group to cats (family Felidae), represent a deeply diverging branch within the cat-like carnivores (Feliformia). With an estimated population size of <10,000 individuals worldwide, the brown hyena (Parahyaena brunnea) represents the rarest of the four extant hyena species and has been listed as Near Threatened by the IUCN. Here, we report a high-coverage genome from a captive bred brown hyena and both mitochondrial and low-coverage nuclear genomes of 14 wild-caught brown hyena individuals from across southern Africa. We find that brown hyena harbor extremely low genetic diversity on both the mitochondrial and nuclear level, most likely resulting from a continuous and ongoing decline in effective population size that started similar to 1 Ma and dramatically accelerated towards the end of the Pleistocene. Despite the strikingly low genetic diversity, we find no evidence of inbreeding within the captive bred individual and reveal phylogeographic structure, suggesting the existence of several potential subpopulations within the species.}, language = {en} }