Abstract:
:We show that the diverse ecoregions of Madagascar share one distinctive climatic feature: unpredictable intra- or interannual precipitation compared with other regions with comparable rainfall. Climatic unpredictability is associated with unpredictable patterns of fruiting and flowering. It is argued that these features have shaped the evolution of distinctive characteristics in the mammalian fauna of the island. Endemic Herpestidae and Tenrecidae and members of five endemic primate families differ from closely related species elsewhere, exhibiting extremes of "fastness" and "slowness" in their life histories. Climatic features may also account for the dearth of frugivorous birds and mammals in Madagascar, and for the evolutionary prevalence of species with large body mass.
journal_name
Proc Natl Acad Sci U S Aauthors
Dewar RE,Richard AFdoi
10.1073/pnas.0704346104subject
Has Abstractpub_date
2007-08-21 00:00:00pages
13723-7issue
34eissn
0027-8424issn
1091-6490pii
0704346104journal_volume
104pub_type
杂志文章abstract::The Xlim-1 gene is activated in the late blastula stage of Xenopus embryogenesis in the mesoderm, and its RNA product becomes concentrated in the Spemann organizer at early gastrula stage. A major regulator of early expression of Xlim-1 is activin or an activin-like signal. We report experiments aiming to identify the...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.94.18.9717
更新日期:1997-09-02 00:00:00
abstract::The attachment of chondrocytes to collagen substrates is stimulated by serum but not by fibronectin. The active material in serum was partially purified and was shown to be a protein by its sensitivity to trypsin and heat and its chromatographic properties. This factor, which we have named chondronectin, is distinct f...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.77.1.385
更新日期:1980-01-01 00:00:00
abstract::Defects in clearing apoptotic debris disrupt tissue and immunological homeostasis, leading to autoimmune and inflammatory diseases. Herein, we report that macrophages from lupus-prone MRL/lpr mice have impaired lysosomal maturation, resulting in heightened ROS production and attenuated lysosomal acidification. Impaire...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1513943113
更新日期:2016-04-12 00:00:00
abstract::Inosine monophosphate dehydrogenase (IMPDH) controls a key metabolic step in the regulation of cell growth and differentiation. This step is the NAD-dependent oxidation of inosine 5' monophosphate (IMP) to xanthosine 5' monophosphate, the rate-limiting step in the synthesis of the guanine nucleotides. Two isoforms of ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.7.3531
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abstract::Morphogenesis during human development relies on the interplay between physiochemical cues that are mediated in part by cellular density and cytoskeletal tension. Here, we interrogated these factors on vascular lineage specification during human-induced pluripotent stem-cell (hiPSC) fate decision. We found that indepe...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1808021115
更新日期:2018-08-07 00:00:00
abstract::We have generated a hybridoma cell line secreting a monoclonal antibody that specifically binds to the surfaces of oligodendrocytes and Schwann cells, the cells involved in myelin formation in the central and peripheral nervous systems, respectively. Binding studies using purified sphingolipids showed that this antibo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.8.2709
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abstract::Although the occurrence of epistasis and pleiotropy is widely accepted at the molecular level, its effect on the adaptive value of fitness-related genes is rarely investigated in plants. Knowledge of these features of a gene is critical to understand the molecular basis of adaptive evolution. Here we investigate the i...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0708209104
更新日期:2007-10-23 00:00:00
abstract::Aromatic polyketides make up a large class of natural products with diverse bioactivity. During biosynthesis, linear poly-β-ketone intermediates are regiospecifically cyclized, yielding molecules with defined cyclization patterns that are crucial for polyketide bioactivity. The aromatase/cyclases (ARO/CYCs) are respon...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1512976112
更新日期:2015-12-15 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.19.7316
更新日期:1986-10-01 00:00:00
abstract::Curved DNA molecules and unusually small circles have been obtained by ligation of synthetic 21-base precursors: (sequence in text). The ligation resulted in the formation of double-stranded oligo-(precursor)s possessing a strong 10.5-base-pair (bp) periodicity of the runs of adenines. Two-dimensional polyacrylamide g...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.4.862
更新日期:1986-02-01 00:00:00
abstract::Monoamines, including dopamine (DA), have been linked to aggression in various species. However, the precise role or roles served by the amine in aggression have been difficult to define because dopaminergic systems influence many behaviors, and all can be altered by changing the function of dopaminergic neurons. In t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1303446110
更新日期:2013-04-09 00:00:00
abstract::We investigated patterns of genetic diversity of Plasmodium falciparum associated with its two main African vectors: Anopheles gambiae and Anopheles funestus. We dissected 10,296 wild-caught mosquitoes from three tropical sites, two in Cameroon (Simbock and Tibati, separated by 320 km) and one in Kenya (Rota, >2,000 k...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0702715104
更新日期:2007-05-08 00:00:00
abstract::The matrix of second derivatives of 21 apparent local energy minima of deca-L-alanine has been computed. The results show that all these conformations are true local energy minima and, therefore, potentially stable conformations for this peptide. Calculations of the relative statistical weights of these conformations ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.63.2.242
更新日期:1969-06-01 00:00:00
abstract::The mature optic nerve cannot regenerate when injured, leaving victims of traumatic nerve damage or diseases such as glaucoma with irreversible visual losses. Recent studies have identified ways to stimulate retinal ganglion cells to regenerate axons part-way through the optic nerve, but it remains unknown whether mat...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1119449109
更新日期:2012-06-05 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1002971107
更新日期:2010-07-06 00:00:00
abstract::The discovery of a steadily growing number of tumor antigens (TAs) has made generic, cell-free, peptide-based cancer vaccines a possible alternative to cytokine-transfected autologous cellular cancer vaccines. The major drawback of peptide vaccines, however, is the poor immunogenicity of peptides. It is commonly thoug...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.94.7.3256
更新日期:1997-04-01 00:00:00
abstract::In confluent fibroblast monolayers, an increase in the selective uptake of free cholesterol (FC) from plasma low density lipoprotein (LDL) was accompanied by an increase in FC efflux. The rate of FC efflux was proportional to the FC content of the cell surface caveolae and to mRNA levels of caveolin, an FC-binding pro...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.94.8.3753
更新日期:1997-04-15 00:00:00
abstract::The cytokines interleukin (IL) 4 and IL-13 induce many of the same biological responses, including class switching to IgE and induction of major histocompatibility complex class II antigens and CD23 on human B cells. It has recently been shown that IL-4 induces the tyrosine phosphorylation of a 170-kDa protein, a subs...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.17.7681
更新日期:1995-08-15 00:00:00
abstract::It has long been recognized that the T-cell compartment has more CD4 helper than CD8 cytotoxic T cells, and this is most evident looking at T-cell development in the thymus. However, it remains unknown how thymocyte development so favors CD4 lineage development. To identify the basis of this asymmetry, we analyzed dev...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1304859110
更新日期:2013-07-30 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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abstract::Esterase 6 is a polymorphic carboxylesterase (carboxylic-ester hydrolase, EC 3.1.1.1) localized to the reproductive tract of male Drosophila melanogaster and transferred to females at copulation. The reproductive fitness of males is strongly affected by temperature and the esterase 6 alleles (active versus null) that ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.9.2962
更新日期:1982-05-01 00:00:00
abstract::The data reported here demonstrate that a preparation extracted from nonpathogenic mycobacteria such as Mycobacterium smegmatis and hereafter referred to as interphase material protected mice against Ehrlich ascitic carcinoma, L-1210 leukemia, and another syngeneic lymphoid leukemia. Furthermore, mice treated by this ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.72.9.3656
更新日期:1975-09-01 00:00:00
abstract::Extrachromosomal copies of the 1.6-kilobase transposable element Tc1 are present at the level of between 0.1 and 1.0 copy per cell in Caenorhabditis elegans strain Bergerac. Extrachromosomal elements were detected and studied using Southern hybridizations employing a Tc1-specific probe. The amount of extrachromosomal ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.81.13.4018
更新日期:1984-07-01 00:00:00
abstract::Hereditary hemochromatosis (HH) is a disorder of iron metabolism caused by common mutations in the gene HFE. The HFE protein binds to transferrin receptor-1 (TfR1) in competition with transferrin, and in vitro, reduces cellular iron by reducing iron uptake. However, in vivo, HFE is strongly expressed by liver macropha...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.242614699
更新日期:2002-11-26 00:00:00
abstract::Unlike αβ-T lineage cells, where the role of ligand in intrathymic selection is well established, the role of ligand in the development of γδ-T cells remains controversial. Here we provide evidence for the role of a bona fide selecting ligand in shaping the γδ-T cell-receptor (TCR) repertoire. Reactivity of the γδ-TCR...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1718328115
更新日期:2018-02-20 00:00:00
abstract::After males of Lasioglossum zephyrum (Hymenoptera: Halictidae) have first been exposed to a conspecific female, the attractiveness of a second female diminishes with increasing genealogical relationship between the two females. The most parsimonious explanation for this is a polygenically controlled female sex pheromo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.80.14.4551
更新日期:1983-07-01 00:00:00
abstract::HOX11, a divergent homeodomain-containing transcription factor, was isolated from the breakpoint of the nonrandom t(10;14)(q24;q11) chromosome translocation found in human T cell acute lymphoblastic leukemias. The translocation places the HOX11 coding sequence under the transcriptional control of TCR alpha/delta regul...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.23.13853
更新日期:1998-11-10 00:00:00
abstract::Pseudomonas fluorescens Pf-5, a rhizosphere-inhabiting bacterium that suppresses several soilborne pathogens of plants, produces the antibiotics pyrrolnitrin, pyoluteorin, and 2,4-diacetylphloroglucinol. A gene necessary for pyrrolnitrin production by Pf-5 was identified as rpoS, which encodes the stationary-phase sig...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.26.12255
更新日期:1995-12-19 00:00:00
abstract::We define an integer invariant [Formula: see text] of a smooth, compact, closed 4-manifold X by minimizing a certain complexity of a trisection of X over all trisections. The good feature of [Formula: see text] is that when [Formula: see text] and X is a homology 4-sphere, then X is diffeomorphic to the 4-sphere. Natu...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1718953115
更新日期:2018-10-23 00:00:00
abstract::Ezrin plays a key role in coupling signal transduction to cortical cell organization. This actin-membrane linker undergoes a series of conformational changes that modulate its interactions with various partners and its localization in membrane or cytosolic pools. Its mobility and exchange rates within and between thes...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.192084599
更新日期:2002-10-01 00:00:00