Displaying publications 41 - 60 of 60 in total

Abstract:
Sort:
  1. Geng X, Haig J, Lin B, Tian C, Zhu S, Cheng Z, et al.
    Environ Sci Technol, 2023 Sep 05;57(35):13067-13078.
    PMID: 37603309 DOI: 10.1021/acs.est.3c03481
    Aerosol black carbon (BC) is a short-lived climate pollutant. The poorly constrained provenance of tropical marine aerosol BC hinders the mechanistic understanding of extreme climate events and oceanic carbon cycling. Here, we collected PM2.5 samples during research cruise NORC2016-10 through South China Sea (SCS) and Northeast Indian Ocean (NEIO) and measured the dual-carbon isotope compositions (δ13C-Δ14C) of BC using hydrogen pyrolysis technique. Aerosol BC exhibits six different δ13C-Δ14C isotopic spaces (i.e., isotope provinces). Liquid fossil fuel combustion, from shipping emissions and adjacent land, is the predominant source of BC over isotope provinces "SCS close to Chinese Mainland" (53.5%), "Malacca Strait" (53.4%), and "Open NEIO" (40.7%). C3 biomass burning is the major contributor to BC over isotope provinces "NEIO close to Southeast Asia" (55.8%), "Open NEIO" (41.3%), and "Open SCS" (40.0%). Coal combustion and C4 biomass burning show higher contributions to BC over "Sunda Strait" and "Open SCS" than the others. Overall, NEIO near the Bay of Bengal, Malacca Strait, and north SCS are three hot spots of fossil fuel-derived BC; the first two areas are also hot spots of biomass-derived BC. The comparable δ13C-Δ14C between BC in aerosol and dissolved BC in surface seawater may suggest atmospheric BC deposition as a potential source of oceanic dissolved BC.
  2. Demarchi B, Stiller J, Grealy A, Mackie M, Deng Y, Gilbert T, et al.
    Proc Natl Acad Sci U S A, 2022 Oct 25;119(43):e2109326119.
    PMID: 35609205 DOI: 10.1073/pnas.2109326119
    The realization that ancient biomolecules are preserved in "fossil" samples has revolutionized archaeological science. Protein sequences survive longer than DNA, but their phylogenetic resolution is inferior; therefore, careful assessment of the research questions is required. Here, we show the potential of ancient proteins preserved in Pleistocene eggshell in addressing a longstanding controversy in human and animal evolution: the identity of the extinct bird that laid large eggs which were exploited by Australia's indigenous people. The eggs had been originally attributed to the iconic extinct flightless bird Genyornis newtoni (†Dromornithidae, Galloanseres) and were subsequently dated to before 50 ± 5 ka by Miller et al. [Nat. Commun. 7, 10496 (2016)]. This was taken to represent the likely extinction date for this endemic megafaunal species and thus implied a role of humans in its demise. A contrasting hypothesis, according to which the eggs were laid by a large mound-builder megapode (Megapodiidae, Galliformes), would therefore acquit humans of their responsibility in the extinction of Genyornis. Ancient protein sequences were reconstructed and used to assess the evolutionary proximity of the undetermined eggshell to extant birds, rejecting the megapode hypothesis. Authentic ancient DNA could not be confirmed from these highly degraded samples, but morphometric data also support the attribution of the eggshell to Genyornis. When used in triangulation to address well-defined hypotheses, paleoproteomics is a powerful tool for reconstructing the evolutionary history in ancient samples. In addition to the clarification of phylogenetic placement, these data provide a more nuanced understanding of the modes of interactions between humans and their environment.
  3. Wu YL, Lee V, Liam CK, Lu S, Park K, Srimuninnimit V, et al.
    Lung Cancer, 2018 12;126:1-8.
    PMID: 30527172 DOI: 10.1016/j.lungcan.2018.10.004
    OBJECTIVE: Patients with advanced non-small-cell lung cancer (NSCLC) with an adenocarcinoma component are recommended to undergo epidermal growth factor receptor (EGFR) mutation testing when being considered for EGFR targeted therapy. We conducted an exploratory analysis to inform the clinical utility of EGFR mutation testing in blood cell-free DNA using the cobas®EGFR Mutation Test v2.

    MATERIALS AND METHODS: Two EGFR mutation tests, a tissue-based assay (cobas® v1) and a tissue- and blood-based assay (cobas® v2) were used to analyze matched biopsy and blood samples (897 paired samples) from three Asian studies of first-line erlotinib with similar intent-to-treat populations. ENSURE was a phase III comparison of erlotinib and gemcitabine/platinum, FASTACT-2 was a phase III study of gemcitabine/platinum plus erlotinib or placebo, and ASPIRATION was a single-arm phase II study of erlotinib. Agreement statistics were evaluated, based on sensitivity and specificity between the two assays in subgroups of patients with increasing tumor burden.

    RESULTS: Patients with discordant EGFR (tissue+/plasma-) mutation status achieved longer progression-free and overall survival than those with concordant (tissue+/plasma+) mutation status. Tumor burden was significantly greater in patients with concordant versus discordant mutations. Pooled analyses of data from the three studies showed a sensitivity of 72.1% (95% confidence interval [CI] 67.8-76.1) and a specificity of 97.9% (95% CI 96.0-99.0) for blood-based testing; sensitivity was greatest in patients with larger baseline tumors.

    CONCLUSIONS: Blood-based EGFR mutation testing demonstrated high specificity and good sensitivity, and offers a convenient and easily accessible diagnostic method to complement tissue-based tests. Patients with a discordant mutation status in plasma and tissue, had improved survival outcomes compared with those with a concordant mutation status, which may be due to their lower tumor burden. These data help to inform the clinical utility of this blood-based assay for the detection of EGFR mutations.

  4. Shen D, Qi H, Lin W, Zhang W, Bian D, Shi X, et al.
    Sci Adv, 2021 Jun;7(23).
    PMID: 34088662 DOI: 10.1126/sciadv.abf0614
    Balancing the biodegradability and mechanical integrity of a bioresorbable scaffold (BRS) with time after implantation to match the remodeling of the scaffolded blood vessel is important, but a key challenge in doing so remains. This study presents a novel intercalated structure of a metallic BRS by introducing a nanoscale Zn sacrificial layer between the nitrided Fe platform and the sirolimus-carrying poly(d,l-lactide) drug coating. The PDLLA-Zn-FeN BRS shows a multistage biodegradation behavior, maintaining mechanical integrity at the initial stage and exhibiting accelerated biodegradation at the subsequent stage in both rabbit abdominal aortas and human coronary arteries, where complete biodegradation was observed about 2 years after implantation. The presence of the nanoscale Zn sacrificial layer with an adjustable thickness also contributes to the tunable biodegradation of BRS and allows the reduction of the metallic strut thickness to 53 μm, with radial strength as strong as that of the current permanent drug-eluting stents.
  5. 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.
  6. 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.
  7. 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.
  8. Dong Y, Kang Z, Zhang Z, Zhang Y, Zhou H, Liu Y, et al.
    Sci Bull (Beijing), 2024 Apr 15;69(7):949-967.
    PMID: 38395651 DOI: 10.1016/j.scib.2024.02.003
    Myocardial ischemia-reperfusion injury (MIRI) is a major hindrance to the success of cardiac reperfusion therapy. Although increased neutrophil infiltration is a hallmark of MIRI, the subtypes and alterations of neutrophils in this process remain unclear. Here, we performed single-cell sequencing of cardiac CD45+ cells isolated from the murine myocardium subjected to MIRI at six-time points. We identified diverse types of infiltrating immune cells and their dynamic changes during MIRI. Cardiac neutrophils showed the most immediate response and largest changes and featured with functionally heterogeneous subpopulations, including Ccl3hi Neu and Ym-1hi Neu, which were increased at 6 h and 1 d after reperfusion, respectively. Ym-1hi Neu selectively expressed genes with protective effects and was, therefore, identified as a novel specific type of cardiac cell in the injured heart. Further analysis indicated that neutrophils and their subtypes orchestrated subsequent immune responses in the cardiac tissues, especially instructing the response of macrophages. The abundance of Ym-1hi Neu was closely correlated with the therapeutic efficacy of MIRI when neutrophils were specifically targeted by anti-Lymphocyte antigen 6 complex locus G6D (Ly6G) or anti-Intercellular cell adhesion molecule-1 (ICAM-1) neutralizing antibodies. In addition, a neutrophil subtype with the same phenotype as Ym-1hi Neu was detected in clinical samples and correlated with prognosis. Ym-1 inhibition exacerbated myocardial injury, whereas Ym-1 supplementation significantly ameliorated injury in MIRI mice, which was attributed to the tilt of Ym-1 on the polarization of macrophages toward the repair phenotype in myocardial tissue. Overall, our findings reveal the anti-inflammatory phenotype of Ym-1hi Neu and highlight its critical role in myocardial protection during the early stages of MIRI.
  9. 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.
  10. 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.
  11. 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.
  12. Gray JE, Okamoto I, Sriuranpong V, Vansteenkiste J, Imamura F, Lee JS, et al.
    Clin Cancer Res, 2019 Nov 15;25(22):6644-6652.
    PMID: 31439584 DOI: 10.1158/1078-0432.CCR-19-1126
    PURPOSE: To assess the utility of the cobas EGFR Mutation Test, with tissue and plasma, for first-line osimertinib therapy for patients with EGFR-mutated (EGFRm; Ex19del and/or L858R) advanced or metastatic non-small cell lung cancer (NSCLC) from the FLAURA study (NCT02296125).

    EXPERIMENTAL DESIGN: Tumor tissue EGFRm status was determined at screening using the central cobas tissue test or a local tissue test. Baseline circulating tumor (ct)DNA EGFRm status was retrospectively determined with the central cobas plasma test.

    RESULTS: Of 994 patients screened, 556 were randomized (289 and 267 with central and local EGFR test results, respectively) and 438 failed screening. Of those randomized from local EGFR test results, 217 patients had available central test results; 211/217 (97%) were retrospectively confirmed EGFRm positive by central cobas tissue test. Using reference central cobas tissue test results, positive percent agreements with cobas plasma test results for Ex19del and L858R detection were 79% [95% confidence interval (CI), 74-84] and 68% (95% CI, 61-75), respectively. Progression-free survival (PFS) superiority with osimertinib over comparator EGFR-TKI remained consistent irrespective of randomization route (central/local EGFRm-positive tissue test). In both treatment arms, PFS was prolonged in plasma ctDNA EGFRm-negative (23.5 and 15.0 months) versus -positive patients (15.2 and 9.7 months).

    CONCLUSIONS: Our results support utility of cobas tissue and plasma testing to aid selection of patients with EGFRm advanced NSCLC for first-line osimertinib treatment. Lack of EGFRm detection in plasma was associated with prolonged PFS versus patients plasma EGFRm positive, potentially due to patients having lower tumor burden.

  13. Pan W, Zhou D, Hijazi ZM, Qureshi SA, Promphan W, Feng Y, et al.
    Catheter Cardiovasc Interv, 2024 Mar;103(4):660-669.
    PMID: 38419402 DOI: 10.1002/ccd.30978
    Transcatheter pulmonary valve replacement (TPVR), also known as percutaneous pulmonary valve implantation, refers to a minimally invasive technique that replaces the pulmonary valve by delivering an artificial pulmonary prosthesis through a catheter into the diseased pulmonary valve under the guidance of X-ray and/or echocardiogram while the heart is still beating not arrested. In recent years, TPVR has achieved remarkable progress in device development, evidence-based medicine proof and clinical experience. To update the knowledge of TPVR in a timely fashion, and according to the latest research and further facilitate the standardized and healthy development of TPVR in Asia, we have updated this consensus statement. After systematical review of the relevant literature with an in-depth analysis of eight main issues, we finally established eight core viewpoints, including indication recommendation, device selection, perioperative evaluation, procedure precautions, and prevention and treatment of complications.
  14. de Manuel M, Barnett R, Sandoval-Velasco M, Yamaguchi N, Garrett Vieira F, Zepeda Mendoza ML, et al.
    Proc Natl Acad Sci U S A, 2020 May 19;117(20):10927-10934.
    PMID: 32366643 DOI: 10.1073/pnas.1919423117
    Lions are one of the world's most iconic megafauna, yet little is known about their temporal and spatial demographic history and population differentiation. We analyzed a genomic dataset of 20 specimens: two ca. 30,000-y-old cave lions (Panthera leo spelaea), 12 historic lions (Panthera leo leo/Panthera leo melanochaita) that lived between the 15th and 20th centuries outside the current geographic distribution of lions, and 6 present-day lions from Africa and India. We found that cave and modern lions shared an ancestor ca. 500,000 y ago and that the 2 lineages likely did not hybridize following their divergence. Within modern lions, we found 2 main lineages that diverged ca. 70,000 y ago, with clear evidence of subsequent gene flow. Our data also reveal a nearly complete absence of genetic diversity within Indian lions, probably due to well-documented extremely low effective population sizes in the recent past. Our results contribute toward the understanding of the evolutionary history of lions and complement conservation efforts to protect the diversity of this vulnerable species.
  15. da Fonseca RR, Couto A, Machado AM, Brejova B, Albertin CB, Silva F, et al.
    Gigascience, 2020 Jan 01;9(1).
    PMID: 31942620 DOI: 10.1093/gigascience/giz152
    BACKGROUND: The giant squid (Architeuthis dux; Steenstrup, 1857) is an enigmatic giant mollusc with a circumglobal distribution in the deep ocean, except in the high Arctic and Antarctic waters. The elusiveness of the species makes it difficult to study. Thus, having a genome assembled for this deep-sea-dwelling species will allow several pending evolutionary questions to be unlocked.

    FINDINGS: We present a draft genome assembly that includes 200 Gb of Illumina reads, 4 Gb of Moleculo synthetic long reads, and 108 Gb of Chicago libraries, with a final size matching the estimated genome size of 2.7 Gb, and a scaffold N50 of 4.8 Mb. We also present an alternative assembly including 27 Gb raw reads generated using the Pacific Biosciences platform. In addition, we sequenced the proteome of the same individual and RNA from 3 different tissue types from 3 other species of squid (Onychoteuthis banksii, Dosidicus gigas, and Sthenoteuthis oualaniensis) to assist genome annotation. We annotated 33,406 protein-coding genes supported by evidence, and the genome completeness estimated by BUSCO reached 92%. Repetitive regions cover 49.17% of the genome.

    CONCLUSIONS: This annotated draft genome of A. dux provides a critical resource to investigate the unique traits of this species, including its gigantism and key adaptations to deep-sea environments.

  16. Stiller J, Feng S, Chowdhury AA, Rivas-González I, Duchêne DA, Fang Q, et al.
    Nature, 2024 Apr 01.
    PMID: 38560995 DOI: 10.1038/s41586-024-07323-1
    Despite tremendous efforts in the past decades, relationships among main avian lineages remain heavily debated without a clear resolution. Discrepancies have been attributed to diversity of species sampled, phylogenetic method and the choice of genomic regions1-3. Here we address these issues by analysing the genomes of 363 bird species4 (218 taxonomic families, 92% of total). Using intergenic regions and coalescent methods, we present a well-supported tree but also a marked degree of discordance. The tree confirms that Neoaves experienced rapid radiation at or near the Cretaceous-Palaeogene boundary. Sufficient loci rather than extensive taxon sampling were more effective in resolving difficult nodes. Remaining recalcitrant nodes involve species that are a challenge to model due to either extreme DNA composition, variable substitution rates, incomplete lineage sorting or complex evolutionary events such as ancient hybridization. Assessment of the effects of different genomic partitions showed high heterogeneity across the genome. We discovered sharp increases in effective population size, substitution rates and relative brain size following the Cretaceous-Palaeogene extinction event, supporting the hypothesis that emerging ecological opportunities catalysed the diversification of modern birds. The resulting phylogenetic estimate offers fresh insights into the rapid radiation of modern birds and provides a taxon-rich backbone tree for future comparative studies.
  17. Rhie A, McCarthy SA, Fedrigo O, Damas J, Formenti G, Koren S, et al.
    Nature, 2021 Apr;592(7856):737-746.
    PMID: 33911273 DOI: 10.1038/s41586-021-03451-0
    High-quality and complete reference genome assemblies are fundamental for the application of genomics to biology, disease, and biodiversity conservation. However, such assemblies are available for only a few non-microbial species1-4. To address this issue, the international Genome 10K (G10K) consortium5,6 has worked over a five-year period to evaluate and develop cost-effective methods for assembling highly accurate and nearly complete reference genomes. Here we present lessons learned from generating assemblies for 16 species that represent six major vertebrate lineages. We confirm that long-read sequencing technologies are essential for maximizing genome quality, and that unresolved complex repeats and haplotype heterozygosity are major sources of assembly error when not handled correctly. Our assemblies correct substantial errors, add missing sequence in some of the best historical reference genomes, and reveal biological discoveries. These include the identification of many false gene duplications, increases in gene sizes, chromosome rearrangements that are specific to lineages, a repeated independent chromosome breakpoint in bat genomes, and a canonical GC-rich pattern in protein-coding genes and their regulatory regions. Adopting these lessons, we have embarked on the Vertebrate Genomes Project (VGP), an international effort to generate high-quality, complete reference genomes for all of the roughly 70,000 extant vertebrate species and to help to enable a new era of discovery across the life sciences.
  18. Feng S, Stiller J, Deng Y, Armstrong J, Fang Q, Reeve AH, et al.
    Nature, 2021 Apr;592(7856):E24.
    PMID: 33833441 DOI: 10.1038/s41586-021-03473-8
  19. Feng S, Stiller J, Deng Y, Armstrong J, Fang Q, Reeve AH, et al.
    Nature, 2020 11;587(7833):252-257.
    PMID: 33177665 DOI: 10.1038/s41586-020-2873-9
    Whole-genome sequencing projects are increasingly populating the tree of life and characterizing biodiversity1-4. Sparse taxon sampling has previously been proposed to confound phylogenetic inference5, and captures only a fraction of the genomic diversity. Here we report a substantial step towards the dense representation of avian phylogenetic and molecular diversity, by analysing 363 genomes from 92.4% of bird families-including 267 newly sequenced genomes produced for phase II of the Bird 10,000 Genomes (B10K) Project. We use this comparative genome dataset in combination with a pipeline that leverages a reference-free whole-genome alignment to identify orthologous regions in greater numbers than has previously been possible and to recognize genomic novelties in particular bird lineages. The densely sampled alignment provides a single-base-pair map of selection, has more than doubled the fraction of bases that are confidently predicted to be under conservation and reveals extensive patterns of weak selection in predominantly non-coding DNA. Our results demonstrate that increasing the diversity of genomes used in comparative studies can reveal more shared and lineage-specific variation, and improve the investigation of genomic characteristics. We anticipate that this genomic resource will offer new perspectives on evolutionary processes in cross-species comparative analyses and assist in efforts to conserve species.
  20. Klionsky DJ, Abdelmohsen K, Abe A, Abedin MJ, Abeliovich H, Acevedo Arozena A, et al.
    Autophagy, 2016;12(1):1-222.
    PMID: 26799652 DOI: 10.1080/15548627.2015.1100356
Filters
Contact Us

Please provide feedback to Administrator ([email protected])

External Links