204 research outputs found

    Differential regulation of myeloid leukemias by the bone marrow microenvironment

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    Like their normal hematopoietic stem cell counterparts, leukemia stem cells (LSC) in chronic myelogenous leukemia (CML) and acute myeloid leukemia (AML) are presumed to reside in specific niches in the bone marrow microenvironment (BMM)1, and may be the cause of relapse following chemotherapy.2 Targeting the niche is a novel strategy to eliminate persistent and drug-resistant LSC. CD443,4 and IL-65 have been implicated previously in the LSC niche. Transforming growth factor (TGF)-ÎČ1 is released during bone remodeling6 and plays a role in maintenance of CML LSCs7, but a role for TGF-ÎČ1 from the BMM has not been defined. Here, we show that alteration of the BMM by osteoblastic cell-specific activation of the parathyroid hormone (PTH) receptor8,9 attenuates BCR-ABL1-induced CML-like myeloproliferative neoplasia (MPN)10 but enhances MLL-AF9-induced AML11 in mouse transplantation models, possibly through opposing effects of increased TGF-ÎČ1 on the respective LSC. PTH treatment caused a 15-fold decrease in LSCs in wildtype mice with CML-like MPN, and reduced engraftment of immune deficient mice with primary human CML cells. These results demonstrate that LSC niches in chronic and acute myeloid leukemias are distinct, and suggest that modulation of the BMM by PTH may be a feasible strategy to reduce LSC, a prerequisite for the cure of CML

    Global Island Monitoring Scheme (GIMS) : a proposal for the long-term coordinated survey and monitoring of native island forest biota

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    Islands harbour evolutionary and ecologically unique biota, which are currently disproportionately threatened by a multitude of anthropogenic factors, including habitat loss, invasive species and climate change. Native forests on oceanic islands are important refugia for endemic species, many of which are rare and highly threatened. Long-term monitoring schemes for those biota and ecosystems are urgently needed: (i) to provide quantitative baselines for detecting changes within island ecosystems, (ii) to evaluate the effectiveness of conservation and management actions, and (iii) to identify general ecological patterns and processes using multiple island systems as repeated 'natural experiments'. In this contribution, we call for a Global Island Monitoring Scheme (GIMS) for monitoring the remaining native island forests, using bryophytes, vascular plants, selected groups of arthropods and vertebrates as model taxa. As a basis for the GIMS, we also present new, optimized monitoring protocols for bryophytes and arthropods that were developed based on former standardized inventory protocols. Effective inventorying and monitoring of native island forests will require: (i) permanent plots covering diverse ecological gradients (e.g. elevation, age of terrain, anthropogenic disturbance); (ii) a multiple-taxa approach that is based on standardized and replicable protocols; (iii) a common set of indicator taxa and community properties that are indicative of native island forests' welfare, building on, and harmonized with existing sampling and monitoring efforts; (iv) capacity building and training of local researchers, collaboration and continuous dialogue with local stakeholders; and (v) long-term commitment by funding agencies to maintain a global network of native island forest monitoring plots.Peer reviewe

    Contributions in honor of Guy G. Musser.

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    450 p. : ill. (some col.), maps ; 26 cm. "Issued December 15, 2009." Includes bibliographical references.Contents: They sort out like nuts and bolts : a scientific biography of Guy G. Musser / Michael D. Carleton -- Taxonomy, distribution, and natural history of the genus Heteromys â€Ș(‬Rodentia: Heteromyidaeâ€Ș)‬ in central and eastern Venezuela, with the description of a new species from the Cordillera de la Costa / Robert P. Anderson and EliĂ©cer E. GutiĂ©rrez -- Review of the Oryzomys couesi complex â€Ș(‬Rodentia: Cricetidae: Sigmodontinaeâ€Ș)‬ in western Mexico / Michael D. Carleton and Joaquin Arroyo-Cabrales -- The antiquity of Rhizomys and independent acquisition of fossorial traits in subterranean muroids / Lawrence J. Flynn -- A new species of Reithrodontomys, subgenus Aporodon â€Ș(‬Cricetidae: Neotominaeâ€Ș)‬, from the highlands of Costa Rica, with comments on Costa Rican and Panamanian Reithrodontomys / Alfred L. Gardner and Michael D. Carleton -- Phylogenetic relationships of harpyionycterine megabats â€Ș(‬Chiroptera: Pteropodidaeâ€Ș)‬ / Norberto P. Giannini, Francisca Cunha Almeida, and Nancy B. Simmons -- A new genus and species of small â€Ș"‬tree-mouseâ€Ș"‬ â€Ș(‬Rodentia, Muridaeâ€Ș)‬ related to the Philippine giant cloud rats / Lawrence R. Heaney, Danilo S. Balete, Eric A. Rickart, M. Josefa Veluz, and Sharon A. Jansa -- Biodiversity and biogeography of the moss-mice of New Guinea : a taxonomic revision of Pseudohydromys â€Ș(‬Muridae: Murinaeâ€Ș)‬ / Kristofer M. Helgen and Lauren E. Helgen -- Systematic revision of sub-Saharan African dormice â€Ș(‬Rodentia: Gliridaeâ€Ș)‬. Part 2, Description of a new species of Graphiurus from the central Congo Basin, including morphological and ecological niche comparisons with G. crassicaudatus and G. lorraineus / Mary Ellen Holden and Rebecca S. Levine -- Descriptions of new species of Crocidura â€Ș(‬Soricomorpha: Soricidaeâ€Ș)‬ from mainland Southeast Asia, with synopses of previously described species and remarks on biogeography / Paulina D. Jenkins, Darrin P. Lunde, and Clive B. Moncrieff -- The six opossums of FĂ©lix de Azara : identification, taxonomic history, neotype designations, and nomenclatural recommendations / Robert S. Voss, Philip Myers, François Catzeflis, Ana Paula Carmignotto, and Josefina Barreiro -- Skull and dentition of Willeumys korthi, nov. gen. et sp., a cricetid rodent from the Oligocene â€Ș(‬Orellanâ€Ș)‬ of Wyoming / John H. Wahlert

    Exploring Demographic, Physical, and Historical Explanations for the Genetic Structure of Two Lineages of Greater Antillean Bats

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    Observed patterns of genetic structure result from the interactions of demographic, physical, and historical influences on gene flow. The particular strength of various factors in governing gene flow, however, may differ between species in biologically relevant ways. We investigated the role of demographic factors (population size and sex-biased dispersal) and physical features (geographic distance, island size and climatological winds) on patterns of genetic structure and gene flow for two lineages of Greater Antillean bats. We used microsatellite genetic data to estimate demographic characteristics, infer population genetic structure, and estimate gene flow among island populations of Erophylla sezekorni/E. bombifrons and Macrotus waterhousii (Chiroptera: Phyllostomidae). Using a landscape genetics approach, we asked if geographic distance, island size, or climatological winds mediate historical gene flow in this system. Samples from 13 islands spanning Erophylla's range clustered into five genetically distinct populations. Samples of M. waterhousii from eight islands represented eight genetically distinct populations. While we found evidence that a majority of historical gene flow between genetic populations was asymmetric for both lineages, we were not able to entirely rule out incomplete lineage sorting in generating this pattern. We found no evidence of contemporary gene flow except between two genetic populations of Erophylla. Both lineages exhibited significant isolation by geographic distance. Patterns of genetic structure and gene flow, however, were not explained by differences in relative effective population sizes, island area, sex-biased dispersal (tested only for Erophylla), or surface-level climatological winds. Gene flow among islands appears to be highly restricted, particularly for M. waterhousii, and we suggest that this species deserves increased taxonomic attention and conservation concern

    Identification of genes required for eye development by high-throughput screening of mouse knockouts.

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    Despite advances in next generation sequencing technologies, determining the genetic basis of ocular disease remains a major challenge due to the limited access and prohibitive cost of human forward genetics. Thus, less than 4,000 genes currently have available phenotype information for any organ system. Here we report the ophthalmic findings from the International Mouse Phenotyping Consortium, a large-scale functional genetic screen with the goal of generating and phenotyping a null mutant for every mouse gene. Of 4364 genes evaluated, 347 were identified to influence ocular phenotypes, 75% of which are entirely novel in ocular pathology. This discovery greatly increases the current number of genes known to contribute to ophthalmic disease, and it is likely that many of the genes will subsequently prove to be important in human ocular development and disease

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & NemĂ©sio 2007; Donegan 2008, 2009; NemĂ©sio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    Erratum to: Scaling up strategies of the chronic respiratory disease programme of the European Innovation Partnership on Active and Healthy Ageing (Action Plan B3: Area 5)

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