Displaying publications 1 - 20 of 31 in total

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  1. Fulltext Extended survival of Pleistocene Siberian wolves into the early 20th century on the island of Honshū
    Niemann J, Gopalakrishnan S, Yamaguchi N, Ramos-Madrigal J, Wales N, Gilbert MTP, et al.
    iScience, 2021 Jan 22;24(1):101904.
    PMID: 33364590 DOI: 10.1016/j.isci.2020.101904
    The Japanese or Honshū wolf was one the most distinct gray wolf subspecies due to its small stature and endemicity to the islands of Honshū, Shikoku, and Kyūshū. Long revered as a guardian of farmers and travellers, it was persecuted from the 17th century following a rabies epidemic, which led to its extinction in the early 20th century. To better understand its evolutionary history, we sequenced the nuclear genome of a 19th century Honshū wolf specimen to an average depth of coverage of 3.7✕. We find Honshū wolves were closely related to a lineage of Siberian wolves that were previously believed to have gone extinct in the Late Pleistocene, thereby extending the survival of this ancient lineage until the early 20th century. We also detected significant gene flow between Japanese dogs and the Honshū wolf, corroborating previous reports on Honshū wolf dog interbreeding.
  2. Fulltext Using metabarcoding to compare the suitability of two blood-feeding leech species for sampling mammalian diversity in North Borneo
    Drinkwater R, Schnell IB, Bohmann K, Bernard H, Veron G, Clare E, et al.
    Mol Ecol Resour, 2019 Jan;19(1):105-117.
    PMID: 30225935 DOI: 10.1111/1755-0998.12943
    The application of high-throughput sequencing (HTS) for metabarcoding of mixed samples offers new opportunities in conservation biology. Recently, the successful detection of prey DNA from the guts of leeches has raised the possibility that these, and other blood-feeding invertebrates, might serve as useful samplers of mammals. Yet little is known about whether sympatric leech species differ in their feeding preferences, and whether this has a bearing on their relative suitability for monitoring local mammalian diversity. To address these questions, we collected spatially matched samples of two congeneric leech species Haemadipsa picta and Haemadipsa sumatrana from lowland rainforest in Borneo. For each species, we pooled ~500 leeches into batches of 10 individuals, performed PCR to target a section of the mammalian 16S rRNA locus and undertook sequencing of amplicon libraries using an Illumina MiSeq. In total, we identified sequences from 14 mammalian genera, spanning nine families and five orders. We found greater numbers of detections, and higher diversity of OTUs, in H. picta compared with H. sumatrana, with rodents only present in the former leech species. However, comparison of samples from across the landscape revealed no significant difference in mammal community composition between the leech species. We therefore suggest that H. picta is the more suitable iDNA sampler in this degraded Bornean forest. We conclude that the choice of invertebrate sampler can influence the detectability of different mammal groups and that this should be accounted for when designing iDNA studies.
  3. Fulltext The first complete mitochondrial genome data of Hippocampus kuda originating from Malaysia
    Jahari PNS, Abdul Malik NF, Shamsir MS, Gilbert MTP, Mohd Salleh F
    Data Brief, 2020 Aug;31:105721.
    PMID: 32490085 DOI: 10.1016/j.dib.2020.105721
    The spotted seahorse, Hippocampus kuda population is exponentially decreasing globally due to habitat loss contributed by massive coastal urbanization as well as its large exploitation for Chinese herbal medicine. Genomic data would be highly useful to improve biomonitoring of seahorse populations in Malaysia via the usage of non-invasive approaches such as water environmental DNA. Here we report the first complete mitogenome of two H. kuda individuals originating from Malaysia, generated using BGISEQ-500RS sequencer. The lengths of both mitogenomes are 16,529bp, consisting of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a control region. The overall base composition was 32.46% for A, 29.40% for T, 14.73% for G and 23.41% for C with AT rich features (61.86%). The gene organization of Malaysian H. kuda were similar to that of most teleost species. A phylogenetic analysis of the genome against mtDNA data from other Hippocampus species showed that Malaysian H. kuda samples clustered with H. capensis, H. reidi and H. kuda. Notably however, analysis of the data using BLASTn revealed they had 99.18% similarity to H. capensis, and only 97.66% to H. kuda and H. reidi, which are all part of the unresolved H. kuda complex. The mitogenomes are deposited in Genbank under the accession number MT221436 (HK1) and MT221436 (HK2).
  4. Fulltext Protective role of the vulture facial skin and gut microbiomes aid adaptation to scavenging
    Zepeda Mendoza ML, Roggenbuck M, Manzano Vargas K, Hansen LH, Brunak S, Gilbert MTP, et al.
    Acta Vet Scand, 2018 Oct 11;60(1):61.
    PMID: 30309375 DOI: 10.1186/s13028-018-0415-3
    BACKGROUND: Vultures have adapted the remarkable ability to feed on carcasses that may contain microorganisms that would be pathogenic to most other animals. The holobiont concept suggests that the genetic basis of such adaptation may not only lie within their genomes, but additionally in their associated microbes. To explore this, we generated shotgun DNA sequencing datasets of the facial skin and large intestine microbiomes of the black vulture (Coragyps atratus) and the turkey vulture (Cathartes aura). We characterized the functional potential and taxonomic diversity of their microbiomes, the potential pathogenic challenges confronted by vultures, and the microbial taxa and genes that could play a protective role on the facial skin and in the gut.

    RESULTS: We found microbial taxa and genes involved in diseases, such as dermatitis and pneumonia (more abundant on the facial skin), and gas gangrene and food poisoning (more abundant in the gut). Interestingly, we found taxa and functions with potential for playing beneficial roles, such as antilisterial bacteria in the gut, and genes for the production of antiparasitics and insecticides on the facial skin. Based on the identified phages, we suggest that phages aid in the control and possibly elimination, as in phage therapy, of microbes reported as pathogenic to a variety of species. Interestingly, we identified Adineta vaga in the gut, an invertebrate that feeds on dead bacteria and protozoans, suggesting a defensive predatory mechanism. Finally, we suggest a colonization resistance role through biofilm formation played by Fusobacteria and Clostridia in the gut.

    CONCLUSIONS: Our results highlight the importance of complementing genomic analyses with metagenomics in order to obtain a clearer understanding of the host-microbial alliance and show the importance of microbiome-mediated health protection for adaptation to extreme diets, such as scavenging.

  5. Fulltext Molecular identification and phylogenetic analysis of a Callosciurus notatus complete mitogenome from Peninsular Malaysia
    Jahari PNS, Mohd Azman S, Munian K, Ahmad Ruzman NH, Shamsir MS, Richter SR, et al.
    Mitochondrial DNA B Resour, 2020 Aug 26;5(3):3004-3006.
    PMID: 33458034 DOI: 10.1080/23802359.2020.1797583
    The mitogenome of a plantain squirrel, Callosciurus notatus, collected from Bukit Tarek Forest Reserve (Extension), Selangor, Malaysia was sequenced using BGISEQ-500RS technology. The 16,582 bp mitogenome consists of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 control region. A phylogenetic and BLASTn analysis against other available datasets showed that the mitogenome matched with 99.49% similarity to a previously published C. notatus mitogenome from Peninsular Malaysia. However, it also diverged by nearly 8% (92.24% match) from a second previously published mitogenome for the same species, sampled in East Kalimantan, Indonesia. This suggests a difference in landscape features between both localities might affect its genetic connectivity.
  6. Fulltext Leech blood-meal invertebrate-derived DNA reveals differences in Bornean mammal diversity across habitats
    Drinkwater R, Jucker T, Potter JHT, Swinfield T, Coomes DA, Slade EM, et al.
    Mol Ecol, 2021 07;30(13):3299-3312.
    PMID: 33171014 DOI: 10.1111/mec.15724
    The application of metabarcoding to environmental and invertebrate-derived DNA (eDNA and iDNA) is a new and increasingly applied method for monitoring biodiversity across a diverse range of habitats. This approach is particularly promising for sampling in the biodiverse humid tropics, where rapid land-use change for agriculture means there is a growing need to understand the conservation value of the remaining mosaic and degraded landscapes. Here we use iDNA from blood-feeding leeches (Haemadipsa picta) to assess differences in mammalian diversity across a gradient of forest degradation in Sabah, Malaysian Borneo. We screened 557 individual leeches for mammal DNA by targeting fragments of the 16S rRNA gene and detected 14 mammalian genera. We recorded lower mammal diversity in the most heavily degraded forest compared to higher quality twice logged forest. Although the accumulation curves of diversity estimates were comparable across these habitat types, diversity was higher in twice logged forest, with more taxa of conservation concern. In addition, our analysis revealed differences between the community recorded in the heavily logged forest and that of the twice logged forest. By revealing differences in mammal diversity across a human-modified tropical landscape, our study demonstrates the value of iDNA as a noninvasive biomonitoring approach in conservation assessments.
  7. Fulltext A genomic exploration of the early evolution of extant cats and their sabre-toothed relatives [version 2; peer review: 2 approved]
    Westbury MV, Barnett R, Sandoval-Velasco M, Gower G, Vieira FG, de Manuel M, et al.
    Open Res Eur, 2021 Jun 21;1:25.
    PMID: 35098251 DOI: 10.12688/openreseurope.13104.2
    Background: The evolutionary relationships of Felidae during their Early-Middle Miocene radiation is contentious. Although the early common ancestors have been subsumed under the grade-group Pseudaelurus, this group is thought to be paraphyletic, including the early ancestors of both modern cats and extinct sabretooths.

    Methods: Here, we sequenced a draft nuclear genome of Smilodon populator, dated to 13,182 ± 90 cal BP, making this the oldest palaeogenome from South America to date, a region known to be problematic for ancient DNA preservation. We analysed this genome, together with genomes from other extinct and extant cats to investigate their phylogenetic relationships.

    Results: We confirm a deep divergence (~20.65 Ma) within sabretoothed cats. Through the analysis of both simulated and empirical data, we show a lack of gene flow between Smilodon and contemporary Felidae.

    Conclusions: Given that some species traditionally assigned to Pseudaelurus originated in the Early Miocene ~20 Ma, this indicates that some species of Pseudaelurus may be younger than the lineages they purportedly gave rise to, further supporting the hypothesis that Pseudaelurus was paraphyletic.

  8. Fulltext An expanded mammal mitogenome dataset from Southeast Asia
    Mohd Salleh F, Ramos-Madrigal J, Peñaloza F, Liu S, Mikkel-Holger SS, Riddhi PP, et al.
    Gigascience, 2017 08 01;6(8):1-8.
    PMID: 28873965 DOI: 10.1093/gigascience/gix053
    Southeast (SE) Asia is 1 of the most biodiverse regions in the world, and it holds approximately 20% of all mammal species. Despite this, the majority of SE Asia's genetic diversity is still poorly characterized. The growing interest in using environmental DNA to assess and monitor SE Asian species, in particular threatened mammals-has created the urgent need to expand the available reference database of mitochondrial barcode and complete mitogenome sequences. We have partially addressed this need by generating 72 new mitogenome sequences reconstructed from DNA isolated from a range of historical and modern tissue samples. Approximately 55 gigabases of raw sequence were generated. From this data, we assembled 72 complete mitogenome sequences, with an average depth of coverage of ×102.9 and ×55.2 for modern samples and historical samples, respectively. This dataset represents 52 species, of which 30 species had no previous mitogenome data available. The mitogenomes were geotagged to their sampling location, where known, to display a detailed geographical distribution of the species. Our new database of 52 taxa will strongly enhance the utility of environmental DNA approaches for monitoring mammals in SE Asia as it greatly increases the likelihoods that identification of metabarcoding sequencing reads can be assigned to reference sequences. This magnifies the confidence in species detections and thus allows more robust surveys and monitoring programmes of SE Asia's threatened mammal biodiversity. The extensive collections of historical samples from SE Asia in western and SE Asian museums should serve as additional valuable material to further enrich this reference database.
  9. MobiSeq: De novo SNP discovery in model and non-model species through sequencing the flanking region of transposable elements
    Rey-Iglesia A, Gopalakrishan S, Carøe C, Alquezar-Planas DE, Ahlmann Nielsen A, Röder T, et al.
    Mol Ecol Resour, 2019 Mar;19(2):512-525.
    PMID: 30575257 DOI: 10.1111/1755-0998.12984
    In recent years, the availability of reduced representation library (RRL) methods has catalysed an expansion of genome-scale studies to characterize both model and non-model organisms. Most of these methods rely on the use of restriction enzymes to obtain DNA sequences at a genome-wide level. These approaches have been widely used to sequence thousands of markers across individuals for many organisms at a reasonable cost, revolutionizing the field of population genomics. However, there are still some limitations associated with these methods, in particular the high molecular weight DNA required as starting material, the reduced number of common loci among investigated samples, and the short length of the sequenced site-associated DNA. Here, we present MobiSeq, a RRL protocol exploiting simple laboratory techniques, that generates genomic data based on PCR targeted enrichment of transposable elements and the sequencing of the associated flanking region. We validate its performance across 103 DNA extracts derived from three mammalian species: grey wolf (Canis lupus), red deer complex (Cervus sp.) and brown rat (Rattus norvegicus). MobiSeq enables the sequencing of hundreds of thousands loci across the genome and performs SNP discovery with relatively low rates of clonality. Given the ease and flexibility of MobiSeq protocol, the method has the potential to be implemented for marker discovery and population genomics across a wide range of organisms-enabling the exploration of diverse evolutionary and conservation questions.
  10. Fulltext Population genomics of grey wolves and wolf-like canids in North America
    Sinding MS, Gopalakrishan S, Vieira FG, Samaniego Castruita JA, Raundrup K, Heide Jørgensen MP, et al.
    PLoS Genet, 2018 11;14(11):e1007745.
    PMID: 30419012 DOI: 10.1371/journal.pgen.1007745
    North America is currently home to a number of grey wolf (Canis lupus) and wolf-like canid populations, including the coyote (Canis latrans) and the taxonomically controversial red, Eastern timber and Great Lakes wolves. We explored their population structure and regional gene flow using a dataset of 40 full genome sequences that represent the extant diversity of North American wolves and wolf-like canid populations. This included 15 new genomes (13 North American grey wolves, 1 red wolf and 1 Eastern timber/Great Lakes wolf), ranging from 0.4 to 15x coverage. In addition to providing full genome support for the previously proposed coyote-wolf admixture origin for the taxonomically controversial red, Eastern timber and Great Lakes wolves, the discriminatory power offered by our dataset suggests all North American grey wolves, including the Mexican form, are monophyletic, and thus share a common ancestor to the exclusion of all other wolves. Furthermore, we identify three distinct populations in the high arctic, one being a previously unidentified "Polar wolf" population endemic to Ellesmere Island and Greenland. Genetic diversity analyses reveal particularly high inbreeding and low heterozygosity in these Polar wolves, consistent with long-term isolation from the other North American wolves.
  11. Kouprey (Bos sauveli) genomes unveil polytomic origin of wild Asian Bos
    Sinding MS, Ciucani MM, Ramos-Madrigal J, Carmagnini A, Rasmussen JA, Feng S, et al.
    iScience, 2021 Nov 19;24(11):103226.
    PMID: 34712923 DOI: 10.1016/j.isci.2021.103226
    The evolution of the genera Bos and Bison, and the nature of gene flow between wild and domestic species, is poorly understood, with genomic data of wild species being limited. We generated two genomes from the likely extinct kouprey (Bos sauveli) and analyzed them alongside other Bos and Bison genomes. We found that B. sauveli possessed genomic signatures characteristic of an independent species closely related to Bos javanicus and Bos gaurus. We found evidence for extensive incomplete lineage sorting across the three species, consistent with a polytomic diversification of the major ancestry in the group, potentially followed by secondary gene flow. Finally, we detected significant gene flow from an unsampled Asian Bos-like source into East Asian zebu cattle, demonstrating both that the full genomic diversity and evolutionary history of the Bos complex has yet to be elucidated and that museum specimens and ancient DNA are valuable resources to do so.
  12. Evolutionary history of the extinct Sardinian dhole
    Ciucani MM, Jensen JK, Sinding MS, Smith O, Lucenti SB, Rosengren E, et al.
    Curr Biol, 2021 Dec 20;31(24):5571-5579.e6.
    PMID: 34655517 DOI: 10.1016/j.cub.2021.09.059
    The Sardinian dhole (Cynotherium sardous)1 was an iconic and unique canid species that was endemic to Sardinia and Corsica until it became extinct at the end of the Late Pleistocene.2-5 Given its peculiar dental morphology, small body size, and high level of endemism, several extant canids have been proposed as possible relatives of the Sardinian dhole, including the Asian dhole and African hunting dog ancestor.3,6-9 Morphometric analyses3,6,8-12 have failed to clarify the evolutionary relationship with other canids.We sequenced the genome of a ca-21,100-year-old Sardinian dhole in order to understand its genomic history and clarify its phylogenetic position. We found that it represents a separate taxon from all other living canids from Eurasia, Africa, and North America, and that the Sardinian dhole lineage diverged from the Asian dhole ca 885 ka. We additionally detected historical gene flow between the Sardinian and Asian dhole lineages, which ended approximately 500-300 ka, when the land bridge between Sardinia and mainland Italy was already broken, severing their population connectivity. Our sample showed low genome-wide diversity compared to other extant canids-probably a result of the long-term isolation-that could have contributed to the subsequent extinction of the Sardinian dhole.
  13. Historical population declines prompted significant genomic erosion in the northern and southern white rhinoceros (Ceratotherium simum)
    Sánchez-Barreiro F, Gopalakrishnan S, Ramos-Madrigal J, Westbury MV, de Manuel M, Margaryan A, et al.
    Mol Ecol, 2021 12;30(23):6355-6369.
    PMID: 34176179 DOI: 10.1111/mec.16043
    Large vertebrates are extremely sensitive to anthropogenic pressure, and their populations are declining fast. The white rhinoceros (Ceratotherium simum) is a paradigmatic case: this African megaherbivore has suffered a remarkable decline in the last 150 years due to human activities. Its subspecies, the northern (NWR) and the southern white rhinoceros (SWR), however, underwent opposite fates: the NWR vanished quickly, while the SWR recovered after the severe decline. Such demographic events are predicted to have an erosive effect at the genomic level, linked to the extirpation of diversity, and increased genetic drift and inbreeding. However, there is little empirical data available to directly reconstruct the subtleties of such processes in light of distinct demographic histories. Therefore, we generated a whole-genome, temporal data set consisting of 52 resequenced white rhinoceros genomes, representing both subspecies at two time windows: before and during/after the bottleneck. Our data reveal previously unknown population structure within both subspecies, as well as quantifiable genomic erosion. Genome-wide heterozygosity decreased significantly by 10% in the NWR and 36% in the SWR, and inbreeding coefficients rose significantly by 11% and 39%, respectively. Despite the remarkable loss of genomic diversity and recent inbreeding it suffered, the only surviving subspecies, the SWR, does not show a significant accumulation of genetic load compared to its historical counterpart. Our data provide empirical support for predictions about the genomic consequences of shrinking populations, and our findings have the potential to inform the conservation efforts of the remaining white rhinoceroses.
  14. Palaeogenomic insights into the origins of French grapevine diversity
    Ramos-Madrigal J, Runge AKW, Bouby L, Lacombe T, Samaniego Castruita JA, Adam-Blondon AF, et al.
    Nat Plants, 2019 Jun;5(6):595-603.
    PMID: 31182840 DOI: 10.1038/s41477-019-0437-5
    The Eurasian grapevine (Vitis vinifera) has long been important for wine production as well as being a food source. Despite being clonally propagated, modern cultivars exhibit great morphological and genetic diversity, with thousands of varieties described in historic and contemporaneous records. Through historical accounts, some varieties can be traced to the Middle Ages, but the genetic relationships between ancient and modern vines remain unknown. We present target-enriched genome-wide sequencing data from 28 archaeological grape seeds dating to the Iron Age, Roman era and medieval period. When compared with domesticated and wild accessions, we found that the archaeological samples were closely related to western European cultivars used for winemaking today. We identified seeds with identical genetic signatures present at different Roman sites, as well as seeds sharing parent-offspring relationships with varieties grown today. Furthermore, we discovered that one seed dated to ~1100 CE was a genetic match to 'Savagnin Blanc', providing evidence for 900 years of uninterrupted vegetative propagation.
  15. Fulltext Historic Sampling of a Vanishing Beast: Population Structure and Diversity in the Black Rhinoceros
    Sánchez-Barreiro F, De Cahsan B, Westbury MV, Sun X, Margaryan A, Fontsere C, et al.
    Mol Biol Evol, 2023 Sep 01;40(9).
    PMID: 37561011 DOI: 10.1093/molbev/msad180
    The black rhinoceros (Diceros bicornis L.) is a critically endangered species historically distributed across sub-Saharan Africa. Hunting and habitat disturbance have diminished both its numbers and distribution since the 19th century, but a poaching crisis in the late 20th century drove them to the brink of extinction. Genetic and genomic assessments can greatly increase our knowledge of the species and inform management strategies. However, when a species has been severely reduced, with the extirpation and artificial admixture of several populations, it is extremely challenging to obtain an accurate understanding of historic population structure and evolutionary history from extant samples. Therefore, we generated and analyzed whole genomes from 63 black rhinoceros museum specimens collected between 1775 and 1981. Results showed that the black rhinoceros could be genetically structured into six major historic populations (Central Africa, East Africa, Northwestern Africa, Northeastern Africa, Ruvuma, and Southern Africa) within which were nested four further subpopulations (Maasailand, southwestern, eastern rift, and northern rift), largely mirroring geography, with a punctuated north-south cline. However, we detected varying degrees of admixture among groups and found that several geographical barriers, most prominently the Zambezi River, drove population discontinuities. Genomic diversity was high in the middle of the range and decayed toward the periphery. This comprehensive historic portrait also allowed us to ascertain the ancestry of 20 resequenced genomes from extant populations. Lastly, using insights gained from this unique temporal data set, we suggest management strategies, some of which require urgent implementation, for the conservation of the remaining black rhinoceros diversity.
  16. Fulltext Pre-extinction Demographic Stability and Genomic Signatures of Adaptation in the Woolly Rhinoceros
    Lord E, Dussex N, Kierczak M, Díez-Del-Molino D, Ryder OA, Stanton DWG, et al.
    Curr Biol, 2020 10 05;30(19):3871-3879.e7.
    PMID: 32795436 DOI: 10.1016/j.cub.2020.07.046
    Ancient DNA has significantly improved our understanding of the evolution and population history of extinct megafauna. However, few studies have used complete ancient genomes to examine species responses to climate change prior to extinction. The woolly rhinoceros (Coelodonta antiquitatis) was a cold-adapted megaherbivore widely distributed across northern Eurasia during the Late Pleistocene and became extinct approximately 14 thousand years before present (ka BP). While humans and climate change have been proposed as potential causes of extinction [1-3], knowledge is limited on how the woolly rhinoceros was impacted by human arrival and climatic fluctuations [2]. Here, we use one complete nuclear genome and 14 mitogenomes to investigate the demographic history of woolly rhinoceros leading up to its extinction. Unlike other northern megafauna, the effective population size of woolly rhinoceros likely increased at 29.7 ka BP and subsequently remained stable until close to the species' extinction. Analysis of the nuclear genome from a ∼18.5-ka-old specimen did not indicate any increased inbreeding or reduced genetic diversity, suggesting that the population size remained steady for more than 13 ka following the arrival of humans [4]. The population contraction leading to extinction of the woolly rhinoceros may have thus been sudden and mostly driven by rapid warming in the Bølling-Allerød interstadial. Furthermore, we identify woolly rhinoceros-specific adaptations to arctic climate, similar to those of the woolly mammoth. This study highlights how species respond differently to climatic fluctuations and further illustrates the potential of palaeogenomics to study the evolutionary history of extinct species.
  17. Fulltext Genomes of Pleistocene Siberian Wolves Uncover Multiple Extinct Wolf Lineages
    Ramos-Madrigal J, Sinding MS, Carøe C, Mak SST, Niemann J, Samaniego Castruita JA, et al.
    Curr Biol, 2021 01 11;31(1):198-206.e8.
    PMID: 33125870 DOI: 10.1016/j.cub.2020.10.002
    Extant Canis lupus genetic diversity can be grouped into three phylogenetically distinct clades: Eurasian and American wolves and domestic dogs.1 Genetic studies have suggested these groups trace their origins to a wolf population that expanded during the last glacial maximum (LGM)1-3 and replaced local wolf populations.4 Moreover, ancient genomes from the Yana basin and the Taimyr peninsula provided evidence of at least one extinct wolf lineage that dwelled in Siberia during the Pleistocene.35 Previous studies have suggested that Pleistocene Siberian canids can be classified into two groups based on cranial morphology. Wolves in the first group are most similar to present-day populations, although those in the second group possess intermediate features between dogs and wolves.67 However, whether this morphological classification represents distinct genetic groups remains unknown. To investigate this question and the relationships between Pleistocene canids, present-day wolves, and dogs, we resequenced the genomes of four Pleistocene canids from Northeast Siberia dated between >50 and 14 ka old, including samples from the two morphological categories. We found these specimens cluster with the two previously sequenced Pleistocene wolves, which are genetically more similar to Eurasian wolves. Our results show that, though the four specimens represent extinct wolf lineages, they do not form a monophyletic group. Instead, each Pleistocene Siberian canid branched off the lineage that gave rise to present-day wolves and dogs. Finally, our results suggest the two previously described morphological groups could represent independent lineages similarly related to present-day wolves and dogs.
  18. Fulltext Interspecific Gene Flow Shaped the Evolution of the Genus Canis
    Gopalakrishnan S, Sinding MS, Ramos-Madrigal J, Niemann J, Samaniego Castruita JA, Vieira FG, et al.
    Curr Biol, 2018 11 05;28(21):3441-3449.e5.
    PMID: 30344120 DOI: 10.1016/j.cub.2018.08.041
    The evolutionary history of the wolf-like canids of the genus Canis has been heavily debated, especially regarding the number of distinct species and their relationships at the population and species level [1-6]. We assembled a dataset of 48 resequenced genomes spanning all members of the genus Canis except the black-backed and side-striped jackals, encompassing the global diversity of seven extant canid lineages. This includes eight new genomes, including the first resequenced Ethiopian wolf (Canis simensis), one dhole (Cuon alpinus), two East African hunting dogs (Lycaon pictus), two Eurasian golden jackals (Canis aureus), and two Middle Eastern gray wolves (Canis lupus). The relationships between the Ethiopian wolf, African golden wolf, and golden jackal were resolved. We highlight the role of interspecific hybridization in the evolution of this charismatic group. Specifically, we find gene flow between the ancestors of the dhole and African hunting dog and admixture between the gray wolf, coyote (Canis latrans), golden jackal, and African golden wolf. Additionally, we report gene flow from gray and Ethiopian wolves to the African golden wolf, suggesting that the African golden wolf originated through hybridization between these species. Finally, we hypothesize that coyotes and gray wolves carry genetic material derived from a "ghost" basal canid lineage.
  19. Fulltext Evolutionary History, Genomic Adaptation to Toxic Diet, and Extinction of the Carolina Parakeet
    Gelabert P, Sandoval-Velasco M, Serres A, de Manuel M, Renom P, Margaryan A, et al.
    Curr Biol, 2020 01 06;30(1):108-114.e5.
    PMID: 31839456 DOI: 10.1016/j.cub.2019.10.066
    As the only endemic neotropical parrot to have recently lived in the northern hemisphere, the Carolina parakeet (Conuropsis carolinensis) was an iconic North American bird. The last surviving specimen died in the Cincinnati Zoo in 1918 [1]. The cause of its extinction remains contentious: besides excessive mortality associated to habitat destruction and active hunting, their survival could have been negatively affected by its range having become increasingly patchy [2] or by the exposure to poultry pathogens [3, 4]. In addition, the Carolina parakeet showed a predilection for cockleburs, an herbaceous plant that contains a powerful toxin, carboxyatractyloside, or CAT [5], which did not seem to affect them but made the birds notoriously toxic to most predators [3]. To explore the demographic history of this bird, we generated the complete genomic sequence of a preserved specimen held in a private collection in Espinelves (Girona, Spain), as well as of a close extant relative, Aratinga solstitialis. We identified two non-synonymous genetic changes in two highly conserved proteins known to interact with CAT that could underlie a specific dietary adaptation to this toxin. Our genomic analyses did not reveal evidence of a dramatic past demographic decline in the Carolina parakeet; also, its genome did not exhibit the long runs of homozygosity that are signals of recent inbreeding and are typically found in endangered species. As such, our results suggest its extinction was an abrupt process and thus likely solely attributable to human causes.
  20. Fulltext Genomic Adaptations and Evolutionary History of the Extinct Scimitar-Toothed Cat, Homotherium latidens
    Barnett R, Westbury MV, Sandoval-Velasco M, Vieira FG, Jeon S, Zazula G, et al.
    Curr Biol, 2020 Dec 21;30(24):5018-5025.e5.
    PMID: 33065008 DOI: 10.1016/j.cub.2020.09.051
    Homotherium was a genus of large-bodied scimitar-toothed cats, morphologically distinct from any extant felid species, that went extinct at the end of the Pleistocene [1-4]. They possessed large, saber-form serrated canine teeth, powerful forelimbs, a sloping back, and an enlarged optic bulb, all of which were key characteristics for predation on Pleistocene megafauna [5]. Previous mitochondrial DNA phylogenies suggested that it was a highly divergent sister lineage to all extant cat species [6-8]. However, mitochondrial phylogenies can be misled by hybridization [9], incomplete lineage sorting (ILS), or sex-biased dispersal patterns [10], which might be especially relevant for Homotherium since widespread mito-nuclear discrepancies have been uncovered in modern cats [10]. To examine the evolutionary history of Homotherium, we generated a ∼7x nuclear genome and a ∼38x exome from H. latidens using shotgun and target-capture sequencing approaches. Phylogenetic analyses reveal Homotherium as highly divergent (∼22.5 Ma) from living cat species, with no detectable signs of gene flow. Comparative genomic analyses found signatures of positive selection in several genes, including those involved in vision, cognitive function, and energy consumption, putatively consistent with diurnal activity, well-developed social behavior, and cursorial hunting [5]. Finally, we uncover relatively high levels of genetic diversity, suggesting that Homotherium may have been more abundant than the limited fossil record suggests [3, 4, 11-14]. Our findings complement and extend previous inferences from both the fossil record and initial molecular studies, enhancing our understanding of the evolution and ecology of this remarkable lineage.
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