TY - JOUR A1 - Agne, Stefanie A1 - Naylor, Gavin J. P. A1 - Preick, Michaela A1 - Yang, Lei A1 - Thiel, Ralf A1 - Weigmann, Simon A1 - Paijmans, Johanna L. A. A1 - Barlow, Axel A1 - Hofreiter, Michael A1 - Straube, Nicolas T1 - Taxonomic identification of two poorly known lantern shark species based on mitochondrial DNA from wet-collection paratypes JF - Frontiers in Ecology and Evolution N2 - Etmopteridae (lantern sharks) is the most species-rich family of sharks, comprising more than 50 species. Many species are described from few individuals, and re-collection of specimens is often hindered by the remoteness of their sampling sites. For taxonomic studies, comparative morphological analysis of type specimens housed in natural history collections has been the main source of evidence. In contrast, DNA sequence information has rarely been used. Most lantern shark collection specimens, including the types, were formalin fixed before long-term storage in ethanol solutions. The DNA damage caused by both fixation and preservation of specimens has excluded these specimens from DNA sequence-based phylogenetic analyses so far. However, recent advances in the field of ancient DNA have allowed recovery of wet-collection specimen DNA sequence data. Here we analyse archival mitochondrial DNA sequences, obtained using ancient DNA approaches, of two wet-collection lantern shark paratype specimens, namely Etmopterus litvinovi and E. pycnolepis, for which the type series represent the only known individuals. Target capture of mitochondrial markers from single-stranded DNA libraries allows for phylogenetic placement of both species. Our results suggest synonymy of E. benchleyi with E. litvinovi but support the species status of E. pycnolepis. This revised taxonomy is helpful for future conservation and management efforts, as our results indicate a larger distribution range of E. litvinovi. This study further demonstrates the importance of wet-collection type specimens as genetic resource for taxonomic research. KW - type specimens KW - Etmopterus litvinovi KW - Etmopterus pycnolepis KW - deep-sea KW - sharks KW - archival DNA Y1 - 2022 U6 - https://doi.org/10.3389/fevo.2022.910009 SN - 2296-701X VL - 10 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Barlow, Axel A1 - Hartmann, Stefanie A1 - Gonzalez, Javier A1 - Hofreiter, Michael A1 - Paijmans, Johanna L. A. T1 - Consensify BT - a method for generating pseudohaploid genome sequences from palaeogenomic datasets with reduced error rates JF - Genes / Molecular Diversity Preservation International N2 - A standard practise in palaeogenome analysis is the conversion of mapped short read data into pseudohaploid sequences, frequently by selecting a single high-quality nucleotide at random from the stack of mapped reads. This controls for biases due to differential sequencing coverage, but it does not control for differential rates and types of sequencing error, which are frequently large and variable in datasets obtained from ancient samples. These errors have the potential to distort phylogenetic and population clustering analyses, and to mislead tests of admixture using D statistics. We introduce Consensify, a method for generating pseudohaploid sequences, which controls for biases resulting from differential sequencing coverage while greatly reducing error rates. The error correction is derived directly from the data itself, without the requirement for additional genomic resources or simplifying assumptions such as contemporaneous sampling. For phylogenetic and population clustering analysis, we find that Consensify is less affected by artefacts than methods based on single read sampling. For D statistics, Consensify is more resistant to false positives and appears to be less affected by biases resulting from different laboratory protocols than other frequently used methods. Although Consensify is developed with palaeogenomic data in mind, it is applicable for any low to medium coverage short read datasets. We predict that Consensify will be a useful tool for future studies of palaeogenomes. KW - palaeogenomics KW - ancient DNA KW - sequencing error KW - error reduction KW - D statistics KW - bioinformatics Y1 - 2020 U6 - https://doi.org/10.3390/genes11010050 SN - 2073-4425 VL - 11 IS - 1 PB - MDPI CY - Basel ER - TY - JOUR A1 - Kehlmaier, Christian A1 - Barlow, Axel A1 - Hastings, Alexander K. A1 - Vamberger, Melita A1 - Paijmans, Johanna L. A. A1 - Steadman, David W. A1 - Albury, Nancy A. A1 - Franz, Richard A1 - Hofreiter, Michael A1 - Fritz, Uwe T1 - Tropical ancient DNA reveals relationships of the extinct bahamian giant tortoise Chelonoidis alburyorum JF - Proceedings of the Royal Society of London : Series B, Biological sciences N2 - Ancient DNA of extinct species from the Pleistocene and Holocene has provided valuable evolutionary insights. However, these are largely restricted to mammals and high latitudes because DNA preservation in warm climates is typically poor. In the tropics and subtropics, non-avian reptiles constitute a significant part of the fauna and little is known about the genetics of the many extinct reptiles from tropical islands. We have reconstructed the near-complete mitochondrial genome of an extinct giant tortoise from the Bahamas (Chelonoidis alburyorum) using an approximately 1000-year-old humerus from a water-filled sinkhole (blue hole) on Great Abaco Island. Phylogenetic and molecular clock analyses place this extinct species as closely related to Galapagos (C. niger complex) and Chaco tortoises (C. chilensis), and provide evidence for repeated overseas dispersal in this tortoise group. The ancestors of extant Chelonoidis species arrived in South America from Africa only after the opening of the Atlantic Ocean and dispersed from there to the Caribbean and the Galapagos Islands. Our results also suggest that the anoxic, thermally buffered environment of blue holes may enhance DNA preservation, and thus are opening a window for better understanding evolution and population history of extinct tropical species, which would likely still exist without human impact. KW - Bahamas KW - biogeography KW - extinction KW - palaeontology KW - phylogeny Y1 - 2017 U6 - https://doi.org/10.1098/rspb.2016.2235 SN - 0962-8452 SN - 1471-2954 VL - 284 PB - The Royal Society CY - London ER - TY - JOUR A1 - Taron, Ulrike H. A1 - Lell, Moritz A1 - Barlow, Axel A1 - Paijmans, Johanna L. A. T1 - Testing of Alignment Parameters for Ancient Samples BT - Evaluating and Optimizing Mapping Parameters for Ancient Samples Using the TAPAS Tool JF - Genese N2 - 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. KW - ancient DNA KW - short-read mapping KW - palaeogenomics KW - paleogenomics KW - alignment sensitivity/specificity Y1 - 2018 U6 - https://doi.org/10.3390/genes9030157 SN - 2073-4425 VL - 9 IS - 3 PB - MDPI CY - Basel ER - TY - JOUR A1 - Barlow, Axel A1 - Cahill, James A. A1 - Hartmann, Stefanie A1 - Theunert, Christoph A1 - Xenikoudakis, Georgios A1 - Gonzalez-Fortes, Gloria M. A1 - Paijmans, Johanna L. A. A1 - Rabeder, Gernot A1 - Frischauf, Christine A1 - Garcia-Vazquez, Ana A1 - Murtskhvaladze, Marine A1 - Saarma, Urmas A1 - Anijalg, Peeter A1 - Skrbinsek, Tomaz A1 - Bertorelle, Giorgio A1 - Gasparian, Boris A1 - Bar-Oz, Guy A1 - Pinhasi, Ron A1 - Slatkin, Montgomery A1 - Dalen, Love A1 - Shapiro, Beth A1 - Hofreiter, Michael T1 - Partial genomic survival of cave bears in living brown bears JF - Nature Ecology & Evolution N2 - 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. Y1 - 2018 U6 - https://doi.org/10.1038/s41559-018-0654-8 SN - 2397-334X VL - 2 IS - 10 SP - 1563 EP - 1570 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Förster, Daniel W. A1 - Bull, James K. A1 - Lenz, Dorina A1 - Autenrieth, Marijke A1 - Paijmans, Johanna L. A. A1 - Kraus, Robert H. S. A1 - Nowak, Carsten A1 - Bayerl, Helmut A1 - Kühn, Ralph A1 - Saveljev, Alexander P. A1 - Sindicic, Magda A1 - Hofreiter, Michael A1 - Schmidt, Krzysztof A1 - Fickel, Jörns T1 - Targeted resequencing of coding DNA sequences for SNP discovery in nonmodel species JF - Molecular ecology resources N2 - Targeted capture coupled with high-throughput sequencing can be used to gain information about nuclear sequence variation at hundreds to thousands of loci. Divergent reference capture makes use of molecular data of one species to enrich target loci in other (related) species. This is particularly valuable for nonmodel organisms, for which often no a priori knowledge exists regarding these loci. Here, we have used targeted capture to obtain data for 809 nuclear coding DNA sequences (CDS) in a nonmodel organism, the Eurasian lynx Lynx lynx, using baits designed with the help of the published genome of a related model organism (the domestic cat Felis catus). Using this approach, we were able to survey intraspecific variation at hundreds of nuclear loci in L. lynx across the species’ European range. A large set of biallelic candidate SNPs was then evaluated using a high-throughput SNP genotyping platform (Fluidigm), which we then reduced to a final 96 SNP-panel based on assay performance and reliability; validation was carried out with 100 additional Eurasian lynx samples not included in the SNP discovery phase. The 96 SNP-panel developed from CDS performed very successfully in the identification of individuals and in population genetic structure inference (including the assignment of individuals to their source population). In keeping with recent studies, our results show that genic SNPs can be valuable for genetic monitoring of wildlife species. KW - CDS KW - conservation genetics KW - Eurasian lynx KW - genetic monitoring KW - hybridization capture KW - single nucleotide polymorphism Y1 - 2018 U6 - https://doi.org/10.1111/1755-0998.12924 SN - 1755-098X SN - 1755-0998 VL - 18 IS - 6 SP - 1356 EP - 1373 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Alberti, Federica A1 - Gonzalez, Javier A1 - Paijmans, Johanna L. A. A1 - Basler, Nikolas A1 - Preick, Michaela A1 - Henneberger, Kirstin A1 - Trinks, Alexandra A1 - Rabeder, Gernot A1 - Conard, Nicholas J. A1 - Muenzel, Susanne C. A1 - Joger, Ulrich A1 - Fritsch, Guido A1 - Hildebrandt, Thomas A1 - Hofreiter, Michael A1 - Barlow, Axel T1 - Optimized DNA sampling of ancient bones using Computed Tomography scans JF - Molecular ecology resources N2 - 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. KW - ancient DNA KW - computer tomography KW - palaeogenomics KW - paleogenetics KW - petrous bone Y1 - 2018 U6 - https://doi.org/10.1111/1755-0998.12911 SN - 1755-098X SN - 1755-0998 VL - 18 IS - 6 SP - 1196 EP - 1208 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Gonzalez-Fortes, Gloria M. A1 - Tassi, F. A1 - Trucchi, E. A1 - Henneberger, K. A1 - Paijmans, Johanna L. A. A1 - Diez-del-Molino, D. A1 - Schroeder, H. A1 - Susca, R. R. A1 - Barroso-Ruiz, C. A1 - Bermudez, F. J. A1 - Barroso-Medina, C. A1 - Bettencourt, A. M. S. A1 - Sampaio, H. A. A1 - Salas, A. A1 - de Lombera-Hermida, A. A1 - Fabregas Valcarce, Ramón A1 - Vaquero, M. A1 - Alonso, S. A1 - Lozano, Marina A1 - Rodriguez-Alvarez, Xose Pedro A1 - Fernandez-Rodriguez, C. A1 - Manica, Andrea A1 - Hofreiter, Michael A1 - Barbujani, Guido T1 - A western route of prehistoric human migration from Africa into the Iberian Peninsula JF - Proceedings of the Royal Society of London : B, Biological sciences N2 - Being at the western fringe of Europe, Iberia had a peculiar prehistory and a complex pattern of Neolithization. A few studies, all based on modern populations, reported the presence of DNA of likely African origin in this region, generally concluding it was the result of recent gene flow, probably during the Islamic period. Here, we provide evidence of much older gene flow from Africa to Iberia by sequencing whole genomes from four human remains from northern Portugal and southern Spain dated around 4000 years BP (from the Middle Neolithic to the Bronze Age). We found one of them to carry an unequivocal sub-Saharan mitogenome of most probably West or West-Central African origin, to our knowledge never reported before in prehistoric remains outside Africa. Our analyses of ancient nuclear genomes show small but significant levels of sub-Saharan African affinity in several ancient Iberian samples, which indicates that what we detected was not an occasional individual phenomenon, but an admixture event recognizable at the population level. We interpret this result as evidence of an early migration process from Africa into the Iberian Peninsula through a western route, possibly across the Strait of Gibraltar. KW - palaeogenome KW - Africa KW - Iberia KW - mitochondrial DNA KW - gene flow KW - admixture Y1 - 2019 U6 - https://doi.org/10.1098/rspb.2018.2288 SN - 0962-8452 SN - 1471-2954 VL - 286 IS - 1895 PB - Royal Society CY - London ER - TY - JOUR A1 - Sheng, Gui-Lian A1 - Basler, Nikolas A1 - Ji, Xue-Ping A1 - Paijmans, Johanna L. A. A1 - Alberti, Federica A1 - Preick, Michaela A1 - Hartmann, Stefanie A1 - Westbury, Michael V. A1 - Yuan, Jun-Xia A1 - Jablonski, Nina G. A1 - Xenikoudakis, Georgios A1 - Hou, Xin-Dong A1 - Xiao, Bo A1 - Liu, Jian-Hui A1 - Hofreiter, Michael A1 - Lai, Xu-Long A1 - Barlow, Axel T1 - Paleogenome reveals genetic contribution of extinct giant panda to extant populations JF - Current biology N2 - Historically, the giant panda was widely distributed from northern China to southwestern Asia [1]. As a result of range contraction and fragmentation, extant individuals are currently restricted to fragmented mountain ranges on the eastern margin of the Qinghai-Tibet plateau, where they are distributed among three major population clusters [2]. However, little is known about the genetic consequences of this dramatic range contraction. For example, were regions where giant pandas previously existed occupied by ancestors of present-day populations, or were these regions occupied by genetically distinct populations that are now extinct? If so, is there any contribution of these extinct populations to the genomes of giant pandas living today? To investigate these questions, we sequenced the nuclear genome of an similar to 5,000-year-old giant panda from Jiangdongshan, Teng-chong County in Yunnan Province, China. We find that this individual represents a genetically distinct population that diverged prior to the diversification of modern giant panda populations. We find evidence of differential admixture with this ancient population among modern individuals originating from different populations as well as within the same population. We also find evidence for directional gene flow, which transferred alleles from the ancient population into the modern giant panda lineages. A variable proportion of the genomes of extant individuals is therefore likely derived from the ancient population represented by our sequenced individual. Although extant giant panda populations retain reasonable genetic diversity, our results suggest that this represents only part of the genetic diversity this species harbored prior to its recent range contractions. Y1 - 2019 U6 - https://doi.org/10.1016/j.cub.2019.04.021 SN - 0960-9822 SN - 1879-0445 VL - 29 IS - 10 SP - 1695 EP - 1700 PB - Cell Press CY - Cambridge ER - TY - JOUR A1 - Signore, Anthony V. A1 - Paijmans, Johanna L. A. A1 - Hofreiter, Michael A1 - Fago, Angela A1 - Weber, Roy E. A1 - Springer, Mark S. A1 - Campbell, Kevin L. T1 - Emergence of a chimeric globin pseudogene and increased Hemoglobin Oxygen Affinity Underlie the evolution of aquatic specializations in Sirenia JF - Molecular biology and evolution N2 - As limits on O2 availability during submergence impose severe constraints on aerobic respiration, the oxygen binding globin proteins of marine mammals are expected to have evolved under strong evolutionary pressures during their land-to-sea transition. Here, we address this question for the order Sirenia by retrieving, annotating, and performing detailed selection analyses on the globin repertoire of the extinct Steller’s sea cow (Hydrodamalis gigas), dugong (Dugong dugon), and Florida manatee (Trichechus manatus latirostris) in relation to their closest living terrestrial relatives (elephants and hyraxes). These analyses indicate most loci experienced elevated nucleotide substitution rates during their transition to a fully aquatic lifestyle. While most of these genes evolved under neutrality or strong purifying selection, the rate of nonsynonymous/synonymous replacements increased in two genes (Hbz-T1 and Hba-T1) that encode the α-type chains of hemoglobin (Hb) during each stage of life. Notably, the relaxed evolution of Hba-T1 is temporally coupled with the emergence of a chimeric pseudogene (Hba-T2/Hbq-ps) that contributed to the tandemly linked Hba-T1 of stem sirenians via interparalog gene conversion. Functional tests on recombinant Hb proteins from extant and ancestral sirenians further revealed that the molecular remodeling of Hba-T1 coincided with increased Hb–O2 affinity in early sirenians. Available evidence suggests that this trait evolved to maximize O2 extraction from finite lung stores and suppress tissue O2 offloading, thereby facilitating the low metabolic intensities of extant sirenians. In contrast, the derived reduction in Hb–O2 affinity in (sub)Arctic Steller’s sea cows is consistent with fueling increased thermogenesis by these once colossal marine herbivores. KW - ancient DNA KW - aquatic adaptation KW - gene conversion KW - hemoglobin KW - oxygen affinity KW - molecular evolution KW - myoglobin KW - neuroglobin KW - cytoglobin KW - pseudogene Y1 - 2019 U6 - https://doi.org/10.1093/molbev/msz044 SN - 0737-4038 SN - 1537-1719 VL - 36 IS - 6 SP - 1134 EP - 1147 PB - Oxford Univ. Press CY - Oxford ER -