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1.
bioRxiv ; 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38328071

RESUMO

Most diffuse large B-cell lymphoma (DLBCL) patients treated with bispecific antibodies (BsAb) or chimeric antigen receptor (CAR) T cells fail to achieve durable treatment responses, underscoring the need for a deeper understanding of mechanisms that regulate the immune environment and response to treatment. Here, an integrative, multi-omic approach was employed to characterize DLBCL immune environments, which effectively segregated DLBCLs into four quadrants - termed DLBCL-immune quadrants (IQ) - defined by cell-of-origin and immune-related gene set expression scores. Recurrent genomic alterations were enriched in each IQ, suggesting that lymphoma cell-intrinsic alterations contribute to orchestrating unique DLBCL immune environments. In relapsed/refractory DLBCL patients, DLBCL-IQ assignment correlated significantly with clinical benefit with the CD20 x CD3 BsAb, mosunetuzumab, but not with CD19-directed CAR T cells. DLBCL-IQ provides a new framework to conceptualize the DLBCL immune landscape and uncovers the differential impact of the endogenous immune environment on outcomes to BsAb and CAR T cell treatment.

2.
Cancer Immunol Res ; 12(3): 296-307, 2024 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-38240659

RESUMO

The classical Hodgkin lymphoma (cHL) environment is comprised of a dense and complex immune cell infiltrate interspersed with rare malignant Hodgkin-Reed-Sternberg (HRS) cells. HRS cells are actively surveilled by endogenous T cells, but data linking phenotypic and functional T-cell states with clonality at the single-cell level in cHL is lacking. To address this knowledge gap, we performed paired single-cell RNA and T-cell receptor sequencing on 14 cHL and 5 reactive lymphoid tissue specimens. Conventional CD4+ T cells dominated the cHL landscape. However, recurrent clonal expansion within effector and exhausted CD8+ T-cell and regulatory T-cell clusters was uniquely observed in cHL specimens. Multiplex flow cytometric analysis revealed that most lymphoma-resident T cells produced effector cytokines upon ex vivo restimulation, arguing against a profound dysfunctional T-cell state in cHL. Our results raise new questions about the nature of T cells that mediate the antilymphoma response following programmed cell death protein 1 (PD-1) blockade therapy in cHL.


Assuntos
Doença de Hodgkin , Humanos , Doença de Hodgkin/genética , Células de Reed-Sternberg/metabolismo , Células de Reed-Sternberg/patologia , Citometria de Fluxo/métodos , Linfócitos T Reguladores/metabolismo , Análise de Célula Única
3.
J Clin Oncol ; 42(4): 467-480, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38079587

RESUMO

PURPOSE: A genetic classifier termed LymphGen accurately identifies diffuse large B-cell lymphoma (DLBCL) subtypes vulnerable to Bruton's tyrosine kinase inhibitors (BTKis), but is challenging to implement in the clinic and fails to capture all DLBCLs that benefit from BTKi-based therapy. Here, we developed a novel CD5 gene expression signature as a biomarker of response to BTKi-based therapy in DLBCL. METHODS: CD5 immunohistochemistry (IHC) was performed on 404 DLBCLs to identify CD5 IHC+ and CD5 IHC- cases, which were subsequently characterized at the molecular level through mutational and transcriptional analyses. A 60-gene CD5 gene expression signature (CD5sig) was constructed using genes differentially expressed between CD5 IHC+ and CD5 IHC- non-germinal center B-cell-like (non-GCB DLBCL) DLBCLs. This CD5sig was applied to external DLBCL data sets, including pretreatment biopsies from patients enrolled in the PHOENIX study (n = 584) to define the extent to which the CD5sig could identify non-GCB DLBCLs that benefited from the addition of ibrutinib to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). RESULTS: CD5 expression was observed in 12% of non-GCB DLBCLs. CD5+ DLBCLs displayed transcriptional features of B-cell receptor (BCR) activation and were enriched for BCR-activating mutations known to correlate with BTKi sensitivity. However, most CD5+ DLBCLs lacked canonical BCR-activating mutations or were LymphGen-unclassifiable (LymphGen-Other). The CD5sig recapitulated these findings in multiple independent data sets, indicating its utility in identifying DLBCLs with genetic and nongenetic bases for BCR dependence. Supporting this notion, CD5sig+ DLBCLs derived a selective survival advantage from the addition of ibrutinib to R-CHOP in the PHOENIX study, independent of LymphGen classification. CONCLUSION: CD5sig is a useful biomarker to identify DLBCLs vulnerable to BTKi-based therapies and complements current biomarker approaches by identifying DLBCLs with genetic and nongenetic bases for BTKi sensitivity.


Assuntos
Linfoma Difuso de Grandes Células B , Humanos , Tirosina Quinase da Agamaglobulinemia/genética , Tirosina Quinase da Agamaglobulinemia/metabolismo , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Linfócitos B/patologia , Rituximab/uso terapêutico , Vincristina/uso terapêutico , Biomarcadores , Doxorrubicina/uso terapêutico , Ciclofosfamida/uso terapêutico , Prednisona/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Prognóstico
4.
Nat Microbiol ; 8(12): 2315-2325, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38030898

RESUMO

The prevalence of chronic, non-communicable diseases has risen sharply in recent decades, especially in industrialized countries. While several studies implicate the microbiome in this trend, few have examined the evolutionary history of industrialized microbiomes. Here we sampled 235 ancient dental calculus samples from individuals living in Great Britain (∼2200 BCE to 1853 CE), including 127 well-contextualized London adults. We reconstructed their microbial history spanning the transition to industrialization. After controlling for oral geography and technical biases, we identified multiple oral microbial communities that coexisted in Britain for millennia, including a community associated with Methanobrevibacter, an anaerobic Archaea not commonly prevalent in the oral microbiome of modern industrialized societies. Calculus analysis suggests that oral hygiene contributed to oral microbiome composition, while microbial functions reflected past differences in diet, specifically in dairy and carbohydrate consumption. In London samples, Methanobrevibacter-associated microbial communities are linked with skeletal markers of systemic diseases (for example, periostitis and joint pathologies), and their disappearance is consistent with temporal shifts, including the arrival of the Second Plague Pandemic. This suggests pre-industrialized microbiomes were more diverse than previously recognized, enhancing our understanding of chronic, non-communicable disease origins in industrialized populations.


Assuntos
Cálculos Dentários , Microbiota , Adulto , Humanos , Reino Unido/epidemiologia , Cálculos Dentários/epidemiologia , Dieta , Estilo de Vida
5.
Mol Cancer Ther ; 22(11): 1290-1303, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37643767

RESUMO

DLBCL are aggressive, rapidly proliferating tumors that critically depend on the ATF4-mediated integrated stress response (ISR) to adapt to stress caused by uncontrolled growth, such as hypoxia, amino acid deprivation, and accumulation of misfolded proteins. Here, we show that ISR hyperactivation is a targetable liability in DLBCL. We describe a novel class of compounds represented by BTM-3528 and BTM-3566, which activate the ISR through the mitochondrial protease OMA1. Treatment of tumor cells with compound leads to OMA1-dependent cleavage of DELE1 and OPA1, mitochondrial fragmentation, activation of the eIF2α-kinase HRI, cell growth arrest, and apoptosis. Activation of OMA1 by BTM-3528 and BTM-3566 is mechanistically distinct from inhibitors of mitochondrial electron transport, as the compounds induce OMA1 activity in the absence of acute changes in respiration. We further identify the mitochondrial protein FAM210B as a negative regulator of BTM-3528 and BTM-3566 activity. Overexpression of FAM210B prevents both OMA1 activation and apoptosis. Notably, FAM210B expression is nearly absent in healthy germinal center B-lymphocytes and in derived B-cell malignancies, revealing a fundamental molecular vulnerability which is targeted by BTM compounds. Both compounds induce rapid apoptosis across diverse DLBCL lines derived from activated B-cell, germinal center B-cell, and MYC-rearranged lymphomas. Once-daily oral dosing of BTM-3566 resulted in complete regression of xenografted human DLBCL SU-DHL-10 cells and complete regression in 6 of 9 DLBCL patient-derived xenografts. BTM-3566 represents a first-of-its kind approach of selectively hyperactivating the mitochondrial ISR for treating DLBCL.


Assuntos
Linfoma de Células B , Peptídeo Hidrolases , Humanos , Peptídeo Hidrolases/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais , Linfoma de Células B/tratamento farmacológico , Linfoma de Células B/genética , Linfoma de Células B/metabolismo
6.
J Immunother Cancer ; 11(6)2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37364933

RESUMO

BACKGROUND: PD-1 checkpoint blockade therapy (CBT) has greatly benefited patients with select solid tumors and lymphomas but has limited efficacy against diffuse large B-cell lymphoma (DLBCL). Because numerous inhibitory checkpoint receptors have been implicated in driving tumor-specific T cell dysfunction, we hypothesized that combinatorial CBT would enhance the activity of anti-PD-1-based therapy in DLBCL. T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) is a coinhibitory receptor expressed on dysfunctional tumor-infiltrating T cells, and TIGIT blockade has demonstrated encouraging activity in combination with PD-1 blockade in murine tumor models and in clinical studies. However, the degree to which TIGIT mediates T cell dysfunction in DLBCL has not been fully explored. RESULTS: Here, we demonstrate that TIGIT is broadly expressed on lymphoma-infiltrating T cells (LITs) across a variety of human lymphomas and is frequently coexpressed with PD-1. TIGIT expression is particularly common on LITs in DLBCL, where TIGIT+ LITs often form distinct cellular communities and exhibit significant contact with malignant B cells. TIGIT+/PD-1+ LITs from human DLBCL and murine lymphomas exhibit hypofunctional cytokine production on ex vivo restimulation. In mice with established, syngeneic A20 B-cell lymphomas, TIGIT or PD-1 mono-blockade leads to modest delays in tumor outgrowth, whereas PD-1 and TIGIT co-blockade results in complete rejection of A20 lymphomas in most mice and significantly prolongs survival compared with mice treated with monoblockade therapy. CONCLUSIONS: These results provide rationale for clinical investigation of TIGIT and PD-1 blockade in lymphomas, including DLBCL.


Assuntos
Linfoma Difuso de Grandes Células B , Receptor de Morte Celular Programada 1 , Humanos , Animais , Camundongos , Receptores Imunológicos/metabolismo , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/patologia
7.
Proc Natl Acad Sci U S A ; 120(22): e2213061120, 2023 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-37220274

RESUMO

The evolutionarily recent dispersal of anatomically modern humans (AMH) out of Africa (OoA) and across Eurasia provides a unique opportunity to examine the impacts of genetic selection as humans adapted to multiple new environments. Analysis of ancient Eurasian genomic datasets (~1,000 to 45,000 y old) reveals signatures of strong selection, including at least 57 hard sweeps after the initial AMH movement OoA, which have been obscured in modern populations by extensive admixture during the Holocene. The spatiotemporal patterns of these hard sweeps provide a means to reconstruct early AMH population dispersals OoA. We identify a previously unsuspected extended period of genetic adaptation lasting ~30,000 y, potentially in the Arabian Peninsula area, prior to a major Neandertal genetic introgression and subsequent rapid dispersal across Eurasia as far as Australia. Consistent functional targets of selection initiated during this period, which we term the Arabian Standstill, include loci involved in the regulation of fat storage, neural development, skin physiology, and cilia function. Similar adaptive signatures are also evident in introgressed archaic hominin loci and modern Arctic human groups, and we suggest that this signal represents selection for cold adaptation. Surprisingly, many of the candidate selected loci across these groups appear to directly interact and coordinately regulate biological processes, with a number associated with major modern diseases including the ciliopathies, metabolic syndrome, and neurodegenerative disorders. This expands the potential for ancestral human adaptation to directly impact modern diseases, providing a platform for evolutionary medicine.


Assuntos
Homem de Neandertal , Humanos , Animais , África , Aclimatação , Arábia , Seleção Genética
9.
Blood Adv ; 7(6): 963-970, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-35973200

RESUMO

A failed graft-versus-tumor (GVT) effect is a common mechanism of relapse after allogeneic hematopoietic cell transplantation (alloHCT). Although targeting the PD-1/PD-L1 axis may restore GVT effects, PD-1 blockade exacerbates graft-versus-host disease (GVHD) in murine models, and severe GVHD can occur in patients treated with anti-PD-1 therapy after alloHCT. Therefore, we developed a prospective study to assess the safety and efficacy of pembrolizumab in patients relapsing after alloHCT. Eligible patients received pembrolizumab (200 mg every 3 weeks) for up to 2 years. Twelve patients were enrolled (8 patients with acute myeloid leukemia, 1 patient with myelodysplastic syndrome, 1 patient with classical Hodgkin lymphoma, and 2 patients with diffuse large B-cell lymphoma [DLBCL]). All participants received reduced-intensity preparative regimens with in vivo T-cell depletion. The median time from alloHCT to enrollment was 587 days (range, 101-4211). Three participants (25%) experienced grade 3 to 4 immune-related adverse events (irAE) (pneumonitis, 2 patients; hyperthyroidism, 1 patient), all occurring after 1 to 2 cycles, and resolving after pembrolizumab discontinuation and corticosteroid treatment. irAEs of any grade occurred in 5 patients (42%). No treatment-emergent GVHD was observed. Overall and complete response (CR) rates were 22% (2/9). Both patients achieving CRs had PD-L1 gene-amplified lymphomas and diffuse PD-L1 expression on pretreatment biopsies. An acquired EZH2 mutation was identified at relapse in a patient with DLBCL who achieved an initial CR to pembrolizumab, which was associated with downregulated HLA expression on malignant B cells, implicating EZH2 mutations as a potential immune escape mechanism after PD-1-blockade therapy. In conclusion, after alloHCT, treatment with pembrolizumab is feasible and associated with objective responses in relapsed lymphoid malignancies but can induce severe irAEs, requiring vigilant monitoring. This trial was registered at www.clinicaltrials.gov as #NCT02981914.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Doença de Hodgkin , Humanos , Animais , Camundongos , Antígeno B7-H1 , Estudos Prospectivos , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Recidiva , Doença de Hodgkin/etiologia
10.
Nat Ecol Evol ; 6(12): 2003-2015, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36316412

RESUMO

The role of natural selection in shaping biological diversity is an area of intense interest in modern biology. To date, studies of positive selection have primarily relied on genomic datasets from contemporary populations, which are susceptible to confounding factors associated with complex and often unknown aspects of population history. In particular, admixture between diverged populations can distort or hide prior selection events in modern genomes, though this process is not explicitly accounted for in most selection studies despite its apparent ubiquity in humans and other species. Through analyses of ancient and modern human genomes, we show that previously reported Holocene-era admixture has masked more than 50 historic hard sweeps in modern European genomes. Our results imply that this canonical mode of selection has probably been underappreciated in the evolutionary history of humans and suggest that our current understanding of the tempo and mode of selection in natural populations may be inaccurate.


Assuntos
Hominidae , Seleção Genética , Animais , Humanos , Evolução Biológica , Genoma Humano , Genômica
11.
Sci Rep ; 12(1): 15164, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36071150

RESUMO

Panicum miliaceum L. was domesticated in northern China at least 7000 years ago and was subsequentially adopted in many areas throughout Eurasia. One such locale is Areni-1 an archaeological cave site in Southern Armenia, where vast quantities archaeobotanical material were well preserved via desiccation. The rich botanical material found at Areni-1 includes P. miliaceum grains that were identified morphologically and14C dated to the medieval period (873 ± 36 CE and 1118 ± 35 CE). To investigate the demographic and evolutionary history of the Areni-1 millet, we used ancient DNA extraction, hybridization capture enrichment, and high throughput sequencing to assemble three chloroplast genomes from the medieval grains and then compared these sequences to 50 modern P. miliaceum chloroplast genomes. Overall, the chloroplast genomes contained a low amount of diversity with domesticated accessions separated by a maximum of 5 SNPs and little inference on demography could be made. However, in phylogenies the chloroplast genomes separated into two clades, similar to what has been reported for nuclear DNA from P. miliaceum. The chloroplast genomes of two wild (undomesticated) accessions of P. miliaceum contained a relatively large number of variants, 11 SNPs, not found in the domesticated accessions. These results demonstrate that P. miliaceum grains from archaeological sites can preserve DNA for at least 1000 years and serve as a genetic resource to study the domestication of this cereal crop.


Assuntos
Genoma de Cloroplastos , Panicum , Armênia , Grão Comestível/genética , Milhetes , Panicum/genética
12.
Sci Rep ; 12(1): 7823, 2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35551211

RESUMO

Although nephrite jade has been collected and treasured since the Stone Age, we lack a clear understanding of how it forms during deformation and metasomatism in shear zones. Using microstructural analysis of samples from Taiwan, California, and New Zealand, we propose a conceptual model for the evolution of nephrite jade that distinguishes four nephrite types based on mode of formation and textural characteristics: (1) primary (type 1a) or folded (type 1b) vein nephrite, (2) crenulated nephrite (type 2), (3) foliated semi-nephrite (type 3), and (4) nodular or domainal nephrite (type 4). We interpret the texture of our analysed samples to represent snapshots of a progressive textural evolution similar to that experienced by other deformed and fine-grained metamorphic rocks that develop under fluid-present, greenschist-facies conditions. Our observations suggest that types 2 and 3 nephrite can evolve from vein nephrite (type 1) by the development of crenulated and foliated metamorphic fabrics, during which the most important deformation process is dissolution-precipitation. However, development of metamorphic fabrics can be interrupted by transient brittle deformation, leading to the formation of type 4 nephrite that is characterised by nodular or angular clasts of nephrite in a nephritic matrix.

13.
Mol Ecol ; 31(24): 6407-6421, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-34748674

RESUMO

The Bering Land Bridge connecting North America and Eurasia was periodically exposed and inundated by oscillating sea levels during the Pleistocene glacial cycles. This land connection allowed the intermittent dispersal of animals, including humans, between Western Beringia (far northeast Asia) and Eastern Beringia (northwest North America), changing the faunal community composition of both continents. The Pleistocene glacial cycles also had profound impacts on temperature, precipitation and vegetation, impacting faunal community structure and demography. While these palaeoenvironmental impacts have been studied in many large herbivores from Beringia (e.g., bison, mammoths, horses), the Pleistocene population dynamics of the diverse guild of carnivorans present in the region are less well understood, due to their lower abundances. In this study, we analyse mitochondrial genome data from ancient brown bears (Ursus arctos; n = 103) and lions (Panthera spp.; n = 39), two megafaunal carnivorans that dispersed into North America during the Pleistocene. Our results reveal striking synchronicity in the population dynamics of Beringian lions and brown bears, with multiple waves of dispersal across the Bering Land Bridge coinciding with glacial periods of low sea levels, as well as synchronous local extinctions in Eastern Beringia during Marine Isotope Stage 3. The evolutionary histories of these two taxa underline the crucial biogeographical role of the Bering Land Bridge in the distribution, turnover and maintenance of megafaunal populations in North America.


Assuntos
Leões , Ursidae , Humanos , Cavalos/genética , Animais , Ursidae/genética , Filogenia , DNA Mitocondrial/genética , América do Norte
14.
Science ; 374(6570): eabi9756, 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34793203

RESUMO

Our study on the exact timing and the potential climatic, environmental, and evolutionary consequences of the Laschamps Geomagnetic Excursion has generated the hypothesis that geomagnetism represents an unrecognized driver in environmental and evolutionary change. It is important for this hypothesis to be tested with new data, and encouragingly, none of the studies presented by Picin et al. undermine our model.

15.
Science ; 374(6570): eabh3655, 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34793228

RESUMO

Our paper about the impacts of the Laschamps Geomagnetic Excursion 42,000 years ago has provoked considerable scientific and public interest, particularly in the so-called Adams Event associated with the initial transition of the magnetic poles. Although we welcome the opportunity to discuss our new ideas, Hawks' assertions of misrepresentation are especially disappointing given his limited examination of the material.

16.
Forensic Sci Int ; 328: 111042, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34638089

RESUMO

The Australian Defence Force (ADF) is responsible for the recovery and identification of its historic casualties. With over 30,000 still unrecovered from past conflicts including World War One (WW1) and World War Two (WWII), the Australian Army and Royal Australian Air Force have teams that research, recover, identify and oversee the burial (or reburial) of the remains of soldiers and airmen who continue to be found each year. The Royal Australian Navy is also responsible for its unrecovered casualties. Collectively the priorities of the various services within the ADF are the respectful recovery and treatment of the dead, thorough forensic identification efforts, resolution for families and honouring the ADF's proud history of service and sacrifice. What is unique about the approach of the ADF is that the respective services retain responsibility for their historic losses, while a joint approach is taken on policies and in the utilisation of the pool of forensic specialists. Section One describes the process undertaken by the Australian Army in the recovery, identification and burial or repatriation of soldiers through its specialised unit Unrecovered War Casualties - Army (UWC-A). Section Two describes the role of the Royal Australian Air Force in the recovery of aircraft and service personnel through their specialised unit Historic Unrecovered War Casualties - Air Force (HUWC-AF). An overview of the operations of each service and case studies is presented for each section.


Assuntos
Militares , Austrália , Restos Mortais , Humanos , I Guerra Mundial , II Guerra Mundial
17.
Sci Rep ; 11(1): 21310, 2021 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-34716362

RESUMO

Allophanic tephra-derived soils can sequester sizable quantities of soil organic matter (SOM). However, no studies have visualized the fine internal porous structure of allophanic soil microaggregates, nor studied the carbon structure preserved in such soils or paleosols. We used synchrotron radiation-based transmission X-ray microscopy (TXM) to perform 3D-tomography of the internal porous structure of dominantly allophanic soil microaggregates, and carbon near-edge X-ray absorption fine-structure (C NEXAFS) spectroscopy to characterize SOM in ≤ 12,000-year-old tephra-derived allophane-rich (with minor ferrihydrite) paleosols. The TXM tomography showed a vast network of internal, tortuous nano-pores within an allophanic microaggregate comprising nanoaggregates. SOM in the allophanic paleosols at four sites was dominated by carboxylic/carbonyl functional groups with subordinate quinonic, aromatic, and aliphatic groups. All samples exhibited similar compositions despite differences between the sites. That the SOM does not comprise specific types of functional groups through time implies that the functional groups are relict. The SOM originated at the land/soil surface: ongoing tephra deposition (intermittently or abruptly) then caused the land-surface to rise so that the once-surface horizons were buried more deeply and hence became increasingly isolated from inputs by the surficial/modern organic cycle. The presence of quinonic carbon, from biological processes but vulnerable to oxygen and light, indicates the exceptional protection of SOM and bio-signals in allophanic paleosols, attributable both to the porous allophane (with ferrihydrite) aggregates that occlude the relict SOM from degradation, and to rapid burial by successive tephra-fallout, as well as strong Al-organic chemical bonding. TXM and C NEXAFS spectroscopy help to unravel the fine structure of soils and SOM and are of great potential for soil science studies.

18.
Cell ; 184(19): 4874-4885.e16, 2021 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-34433011

RESUMO

Only five species of the once-diverse Rhinocerotidae remain, making the reconstruction of their evolutionary history a challenge to biologists since Darwin. We sequenced genomes from five rhinoceros species (three extinct and two living), which we compared to existing data from the remaining three living species and a range of outgroups. We identify an early divergence between extant African and Eurasian lineages, resolving a key debate regarding the phylogeny of extant rhinoceroses. This early Miocene (∼16 million years ago [mya]) split post-dates the land bridge formation between the Afro-Arabian and Eurasian landmasses. Our analyses also show that while rhinoceros genomes in general exhibit low levels of genome-wide diversity, heterozygosity is lowest and inbreeding is highest in the modern species. These results suggest that while low genetic diversity is a long-term feature of the family, it has been particularly exacerbated recently, likely reflecting recent anthropogenic-driven population declines.


Assuntos
Evolução Molecular , Genoma , Perissodáctilos/genética , Animais , Demografia , Fluxo Gênico , Variação Genética , Geografia , Heterozigoto , Homozigoto , Especificidade de Hospedeiro , Cadeias de Markov , Mutação/genética , Filogenia , Especificidade da Espécie , Fatores de Tempo
19.
Genes (Basel) ; 12(7)2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202821

RESUMO

The tropical archipelago of Wallacea contains thousands of individual islands interspersed between mainland Asia and Near Oceania, and marks the location of a series of ancient oceanic voyages leading to the peopling of Sahul-i.e., the former continent that joined Australia and New Guinea at a time of lowered sea level-by 50,000 years ago. Despite the apparent deep antiquity of human presence in Wallacea, prior population history research in this region has been hampered by patchy archaeological and genetic records and is largely concentrated upon more recent history that follows the arrival of Austronesian seafarers ~3000-4000 years ago (3-4 ka). To shed light on the deeper history of Wallacea and its connections with New Guinea and Australia, we performed phylogeographic analyses on 656 whole mitogenomes from these three regions, including 186 new samples from eight Wallacean islands and three West Papuan populations. Our results point to a surprisingly dynamic population history in Wallacea, marked by two periods of extensive demographic change concentrated around the Last Glacial Maximum ~15 ka and post-Austronesian contact ~3 ka. These changes appear to have greatly diminished genetic signals informative about the original peopling of Sahul, and have important implications for our current understanding of the population history of the region.


Assuntos
Genética Populacional , Genoma Mitocondrial/genética , Filogenia , Filogeografia , Animais , Arqueologia/história , Ásia , Austrália , Besouros/genética , Feminino , Haplótipos/genética , História Antiga , Humanos , Masculino , Nova Guiné , Oceania
20.
Brief Bioinform ; 22(5)2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-33834210

RESUMO

The current standard practice for assembling individual genomes involves mapping millions of short DNA sequences (also known as DNA 'reads') against a pre-constructed reference genome. Mapping vast amounts of short reads in a timely manner is a computationally challenging task that inevitably produces artefacts, including biases against alleles not found in the reference genome. This reference bias and other mapping artefacts are expected to be exacerbated in ancient DNA (aDNA) studies, which rely on the analysis of low quantities of damaged and very short DNA fragments (~30-80 bp). Nevertheless, the current gold-standard mapping strategies for aDNA studies have effectively remained unchanged for nearly a decade, during which time new software has emerged. In this study, we used simulated aDNA reads from three different human populations to benchmark the performance of 30 distinct mapping strategies implemented across four different read mapping software-BWA-aln, BWA-mem, NovoAlign and Bowtie2-and quantified the impact of reference bias in downstream population genetic analyses. We show that specific NovoAlign, BWA-aln and BWA-mem parameterizations achieve high mapping precision with low levels of reference bias, particularly after filtering out reads with low mapping qualities. However, unbiased NovoAlign results required the use of an IUPAC reference genome. While relevant only to aDNA projects where reference population data are available, the benefit of using an IUPAC reference demonstrates the value of incorporating population genetic information into the aDNA mapping process, echoing recent results based on graph genome representations.


Assuntos
Benchmarking/métodos , Biologia Computacional/métodos , DNA Antigo/análise , Genoma Humano/genética , Alinhamento de Sequência/métodos , Análise de Sequência de DNA/métodos , Algoritmos , DNA Antigo/química , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Polimorfismo de Nucleotídeo Único , Reprodutibilidade dos Testes , Software
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