Notch-induced T cell development requires phosphoinositide-dependent kinase 1

Phosphoinositide-dependent kinase l (PDK1) phosphorylates and activates multiple AGC serine kinases, including protein kinase B (PKB), p70Ribosomal S6 kinase (S6K) and p90Ribosomal S6 kinase (RSK). PDK1 is required for thymocyte differentiation and proliferation, and herein, we explore the molecular basis for these essential functions of PDK1 in T lymphocyte development. A key finding is that PDK1 is required for the expression of key nutrient receptors in T cell progenitors: CD71 the transferrin receptor and CD98 a subunit of L-amino acid transporters. PDK1 is also essential for Notch-mediated trophic and proliferative responses in thymocytes. A PDK1 mutant PDK1 L155E, which supports activation of PKB but no other AGC kinases, can restore CD71 and CD98 expression in pre-T cells and restore thymocyte differentiation. However, PDK1 L155E is insufficient for thymocyte proliferation. The role of PDK1 in thymus development thus extends beyond its ability to regulate PKB. In addition, PDK1 phosphorylation of AGC kinases such as S6K and RSK is also necessary for thymocyte development

Deletion of PEA-15 in mice is associated with specific impairments of spatial learning abilities

<p>Abstract</p> <p>Background</p> <p>PEA-15 is a phosphoprotein that binds and regulates ERK MAP kinase and RSK2 and is highly expressed throughout the brain. PEA-15 alters c-Fos and CREB-mediated transcription as a result of these interactions. To determine if PEA-15 contributes to the function of the nervous system we tested mice lacking PEA-15 in a series of experiments designed to measure learning, sensory/motor function, and stress reactivity.</p> <p>Results</p> <p>We report that PEA-15 null mice exhibited impaired learning in three distinct spatial tasks, while they exhibited normal fear conditioning, passive avoidance, egocentric navigation, and odor discrimination. PEA-15 null mice also had deficient forepaw strength and in limited instances, heightened stress reactivity and/or anxiety. However, these non-cognitive variables did not appear to account for the observed spatial learning impairments. The null mice maintained normal weight, pain sensitivity, and coordination when compared to wild type controls.</p> <p>Conclusion</p> <p>We found that PEA-15 null mice have spatial learning disabilities that are similar to those of mice where ERK or RSK2 function is impaired. We suggest PEA-15 may be an essential regulator of ERK-dependent spatial learning.</p

The future of botanical monography : report from an international workshop, 12–16 March 2012, Smolenice, Slovak Republic

Monographs are fundamental for progress in systematic botany. They are the vehicles for circumscribing and naming taxa, determining distributions and ecology, assessing relationships for formal classification, and interpreting long-term and short-term dimensions of the evolutionary process. Despite their importance, fewer monographs are now being prepared by the newer generation of systematic botanists, who are understandably involved principally with DNA data and analysis, especially for answering phylogenetic, biogeographic, and population genetic questions. As monographs provide hypotheses regarding species boundaries and plant relationships, new insights in many plant groups are urgently needed. Increasing pressures on biodiversity, especially in tropical and developing regions of the world, emphasize this point. The results from a workshop (with 21 participants) reaffirm the central role that monographs play in systematic botany. But, rather than advocating abbreviated models for monographic products, we recommend a full presentation of relevant information. Electronic publication offers numerous means of illustration of taxa, habitats, characters, and statistical and phylogenetic analyses, which previously would have been prohibitively costly. Open Access and semantically enhanced linked electronic publications provide instant access to content from anywhere in the world, and at the same time link this content to all underlying data and digital resources used in the work. Resources in support of monography, especially databases and widely and easily accessible digital literature and specimens, are now more powerful than ever before, but interfacing and interoperability of databases are much needed. Priorities for new resources to be developed include an index of type collections and an online global chromosome database. Funding for sabbaticals for monographers to work uninterrupted on major projects is strongly encouraged. We recommend that doctoral students be assigned smaller genera, or natural portions of larger ones (subgenera, sections, etc.), to gain the necessary expertise for producing a monograph, including training in a broad array of data collection (e.g., morphology, anatomy, palynology, cytogenetics, DNA techniques, ecology, biogeography), data analysis (e.g., statistics, phylogenetics, models), and nomenclature. Training programs, supported by institutes, associations, and agencies, provide means for passing on procedures and perspectives of challenging botanical monography to the next generation of young systematists.Appreciation is expressed to: the Andrew W. Mellon Foundation for financial support that allowed the workshop to be convened; the International Association for Plant Taxonomy (IAPT) for additional financial support for the workshop.http://www.botanik.univie.ac.at/iapt/s_taxon.phpam201

The future of botanical monography : report from an international workshop, 12–16 March 2012, Smolenice, Slovak Republic

Monographs are fundamental for progress in systematic botany. They are the vehicles for circumscribing and naming taxa, determining distributions and ecology, assessing relationships for formal classification, and interpreting long-term and short-term dimensions of the evolutionary process. Despite their importance, fewer monographs are now being prepared by the newer generation of systematic botanists, who are understandably involved principally with DNA data and analysis, especially for answering phylogenetic, biogeographic, and population genetic questions. As monographs provide hypotheses regarding species boundaries and plant relationships, new insights in many plant groups are urgently needed. Increasing pressures on biodiversity, especially in tropical and developing regions of the world, emphasize this point. The results from a workshop (with 21 participants) reaffirm the central role that monographs play in systematic botany. But, rather than advocating abbreviated models for monographic products, we recommend a full presentation of relevant information. Electronic publication offers numerous means of illustration of taxa, habitats, characters, and statistical and phylogenetic analyses, which previously would have been prohibitively costly. Open Access and semantically enhanced linked electronic publications provide instant access to content from anywhere in the world, and at the same time link this content to all underlying data and digital resources used in the work. Resources in support of monography, especially databases and widely and easily accessible digital literature and specimens, are now more powerful than ever before, but interfacing and interoperability of databases are much needed. Priorities for new resources to be developed include an index of type collections and an online global chromosome database. Funding for sabbaticals for monographers to work uninterrupted on major projects is strongly encouraged. We recommend that doctoral students be assigned smaller genera, or natural portions of larger ones (subgenera, sections, etc.), to gain the necessary expertise for producing a monograph, including training in a broad array of data collection (e.g., morphology, anatomy, palynology, cytogenetics, DNA techniques, ecology, biogeography), data analysis (e.g., statistics, phylogenetics, models), and nomenclature. Training programs, supported by institutes, associations, and agencies, provide means for passing on procedures and perspectives of challenging botanical monography to the next generation of young systematists.Appreciation is expressed to: the Andrew W. Mellon Foundation for financial support that allowed the workshop to be convened; the International Association for Plant Taxonomy (IAPT) for additional financial support for the workshop.http://www.botanik.univie.ac.at/iapt/s_taxon.phpam201

Tropical Biology and Research Institutions in South and Southeast Asia since 1500: Botanic Gardens and Scientific Organizations to 1870

Tropical biological stations have become in the last half-century a well-established phenomenon. They are, however, but a modem manifestation of a long tradition of institutionalized study of tropical biological diversity, an approach gradually adopted by Europeans as one response to the needs and challenges of a new environment. This paper describes the growth of early institutions in South and Southeast Asia (and Mauritius), particularly botanic gardens, learned societies, and scientific surveys, and examines their relative successes and failures in relation to their geographical and political circumstances. The interaction among the Dutch, French, and British spheres is examined in relation to the appearance of new ideas. It is concluded that although all these powers were from time to time innovative, the British and Dutch, though in different ways, became the most successful in their lasting influence on pure and applied tropical science. The British network, internally strong and effectively worldwide by the nineteenth century, was notable for its breadth but featured less autonomy for individual units; the Dutch, fortunately situated in Indonesia and heir to an autonomous biological tradition, established in Bogor the beginnings of what became after 1870 a major biological (and, indeed, academic) center

Révision taxonomique et redéfinition du genre &lt;i&gt;Gamblea&lt;/i&gt; (Araliaceae).

La comparaison entre le matériel attribué jusqu’à maintenant au genre est-asiatique Evodiopanax et celui de Gamblea de l’Himalaya oriental et du N Myanmar indique qu’ils ne constituent qu’un seul genre, Gamblea ayant la priorité. Une évaluation des limites taxonomiques au sein de ce genre élargi permet de reconnaître quatre espèces : G. ciliata, distribué de l’Inde, du N Myanmar, du S de la Chine et de l’extrême N du Viêt-Nam à la Chine orientale, qui inclue la var. evodiaefolia reconnue ici, considérée auparavant comme espèce distincte ; G. innovans du Japon ; G. malayana de la Péninsule Malaise et du N Sumatra ; et G. pseudoevodiaefolia limité au SW du Guangxi et au SE du Yunnan en Chine et aux régions limitrophes au N du Viêt-Nam et du Laos. Quatre nouvelles combinaisons sont établies et quatre noms sont lectotypifiés.Comparison of material previously assigned to the east Asian genus Evodiopanax (Araliaceae) with that of Gamblea from the eastern Himalayas and northern Myanmar shows that they comprise a single genus, with Gamblea having priority. A re-evaluation of taxonomic limits within the expanded genus leads to the recognition of four species: G. ciliata extending from India across northern Myanmar, southern China and far northern Viet Nam to eastern China, and including the newly recognized var. evodiaefolia, previously treated as a distinct species; the Japanese G. innovans; G. malayana in peninsular Malaysia and northern Sumatra; and G. pseudoevodiaefolia restricted to southwestern Guangxi and southeastern Yunnan Provinces in China and adjacent northern Viet Nam and Laos. Four new combinations are made and four names are lectotypified

Two new combinations in Brazilian Dendropanax (Araliaceae).

New combinations and lectotypes are here proposed for two Brazilian species of Dendropanax (Araliaceae): Dendropanax simplicifolius for Didymopanax simplicifolius from northern Mato Grosso Amazonian forests, and Dendropanax pruinosus for Gilibertia pruinosa, known only from gallery forests in the Chapada dos Veadeiros region. Both of these species are very poorly known and more collections will be required to achieve a better understanding of their morphological variability and circumscription

Reconstructing the Complex Evolutionary History of the Papuasian Schefflera Radiation Through Herbariomics

With its large proportion of endemic taxa, complex geological past, and location at the confluence of the highly diverse Malesian and Australian floristic regions, Papuasia – the floristic region comprising the Bismarck Archipelago, New Guinea, and the Solomon Islands – represents an ideal natural experiment in plant biogeography. However, scattered knowledge of its flora and limited representation in herbaria have hindered our understanding of the drivers of its diversity. Focusing on the woody angiosperm genus Schefflera (Araliaceae), we ask whether its morphologically defined infrageneric groupings are monophyletic, when these lineages diverged, and where (within Papuasia or elsewhere) they diversified. To address these questions, we use a high-throughput sequencing approach (Hyb-Seq) which combines target capture (with an angiosperm-wide bait kit targeting 353 single-copy nuclear loci) and genome shotgun sequencing (which allows retrieval of regions in high-copy number, e.g., organellar DNA) of historical herbarium collections. To reconstruct the evolutionary history of the genus we reconstruct molecular phylogenies with Bayesian inference, maximum likelihood, and pseudo-coalescent approaches, and co-estimate divergence times and ancestral areas in a Bayesian framework. We find strong support for most infrageneric morphological groupings, as currently circumscribed, and we show the efficacy of the Angiosperms-353 probe kit in resolving both deep and shallow phylogenetic relationships. We infer a sequence of colonization to explain the present-day distribution of Schefflera in Papuasia: from the Sunda Shelf, Schefflera arrived to the Woodlark plate (present-day eastern New Guinea) in the late Oligocene (when most of New Guinea was submerged) and, subsequently (throughout the Miocene), it migrated westwards (to the Maoke and Bird’s Head Plates and thereon) and further diversified, in agreement with previous reconstructions

A synopsis of the Afro-Malagasy species previously included in Schefflera (Araliaceae): resurrection of the genera Astropanax and Neocussonia.

International audienc