Abstract:
:Neuronal specificity in retinal ganglion cells of Xenopus subserves the orderly connections of the optic nerve fibers in the tectum. This specificity derives from positional information acquired by the developing retina at embryonic stages 28-31. Here we report that ganglion cells of embryonic stage 28 eyes can acquire positional information with reference to the major axes of the body not only in the ocular orbit but also at other positions on the side of the body. When returned to the orbit this eye will form appropriate retinotectal connections. Conversely, retinal ganglion cells of stage 31 eyes, which have acquired positional information in the orbit, will retain their original neuronal positional specificities if the formation of retinotectal connections is delayed by grafting the eye to the flank for 30 days before returning it to the orbit. We conclude that neuronal specificity of retinal ganglion cells (a) does not derive from "inducers" unique to the periocular tissues; and (b) persists for some time independently of the establishment of retinotectal connections.
journal_name
Proc Natl Acad Sci U S Aauthors
Hunt RK,Jacobson Mdoi
10.1073/pnas.69.4.780subject
Has Abstractpub_date
1972-04-01 00:00:00pages
780-3issue
4eissn
0027-8424issn
1091-6490journal_volume
69pub_type
杂志文章abstract::Susceptibility of activated T cells to apoptosis must be tightly regulated to ensure sufficient T cell progeny for an effective response, while allowing a rapid depletion of them at the end of the immune response. We show here that a previously isolated, NF-kappa B/rel target gene IEX-1 (Immediate Early response gene ...
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.022326699
更新日期:2002-01-22 00:00:00
abstract::The introduction of foreign genes into early mouse embryos and embryonic stem (ES) cells is invaluable for the analysis of gene function and regulation in the living animal. The use of vectors derived from retroviruses as gene transfer vehicles in this setting has had limited success because of silencing of transgene ...
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.251682798
更新日期:2002-02-19 00:00:00
abstract::A system for studying Z-DNA formation in the Escherichia coli chromosome was developed. Prior investigations in recombinant plasmids showed that alternating (Pur-Pyr) sequences can adopt a left-handed Z-DNA conformation both in vitro and in vivo. We constructed mobile, transposon-based cassettes carrying cloned (Pur-P...
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.91.21.9980
更新日期:1994-10-11 00:00:00
abstract::Ezrin and moesin are components of actin-rich cell surface structures that are thought to function as membrane-cytoskeletal linking proteins. Here we show that a stable complex of ezrin and moesin can be isolated from cultured cells by immunoprecipitation with specific antibodies. The capacity of these two proteins to...
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.90.22.10846
更新日期:1993-11-15 00:00:00
abstract::Keratins 14 and 5 are the structural hallmarks of the basal keratinocytes of the epidermis and outer root sheath (ORS) of the hair follicle. Their genes are controlled in a tissue-specific manner and thus serve as useful tools to elucidate the regulatory mechanisms involved in keratinocyte-specific transcription. Prev...
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.051633598
更新日期:2001-02-27 00:00:00
abstract::The antitumor drug Taxol stabilizes microtubules and reduces their dynamicity, promoting mitotic arrest and cell death. Upon assembly of the alpha/beta-tubulin heterodimer, GTP bound to beta-tubulin is hydrolyzed to GDP reaching a steady-state equilibrium between free tubulin dimers and microtubules. The binding of Ta...
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.0603704103
更新日期:2006-07-05 00:00:00
abstract::A volcanic catastrophe even more devastating than the famous anno Domini 79 Pompeii eruption occurred during the Old Bronze Age at Vesuvius. The 3780-yr-B.P. Avellino plinian eruption produced an early violent pumice fallout and a late pyroclastic surge sequence that covered the volcano surroundings as far as 25 km aw...
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.0508697103
更新日期:2006-03-21 00:00:00
abstract::We have identified a subset of CD56(+)CD3(-) human natural killer (NK) cells that express CD4 and the HIV coreceptors CCR5 and CXCR4. These cells can be productively infected in vitro by both CCR5- and CXCR4-using molecular clones of HIV-1 in a CD4-dependent manner. Analysis of HIV-infected persons showed that viral D...
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.102672999
更新日期:2002-05-14 00:00:00
abstract::To understand non-trivial biological functions, it is crucial to develop minimal synthetic models that capture their basic features. Here, we demonstrate a sequence-independent, reversible control of transcription and gene expression using a photosensitive nucleic acid binder (pNAB). By introducing a pNAB whose affini...
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.0904382106
更新日期:2009-07-28 00:00:00
abstract::Thebaine, an intermediate of morphine biosynthesis in the poppy plant, Papaver somniferum, was transformed to oripavine, codeine, and morphine by rat liver, kidney, and brain microsomes in the presence of an NADPH-generating system. The formation of morphine, codeine, and oripavine was identified by a specific RIA, HP...
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.85.4.1267
更新日期:1988-02-01 00:00:00
abstract::The pore domain of voltage-gated potassium (Kv) channels consists of transmembrane helices S5 and S6, the turret, the pore helix, the selectivity filter, and the loop preceding S6, with a tertiary reentrant structure between S5 and S6. Using biogenic intermediates, mass tagging (pegylation), and a molecular tape measu...
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.1017097108
更新日期:2011-02-22 00:00:00
abstract::Primary tumors secrete factors that alter the microenvironment of distant organs, rendering those organs as fertile soil for subsequent metastatic cancer cell colonization. Although the lungs are exposed to these factors ubiquitously, lung metastases usually develop as a series of discrete lesions. The underlining mol...
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.1100446108
更新日期:2011-03-01 00:00:00
abstract::An approach combining signal detection theory and precise 3D reconstructions from serial section electron microscopy (3DEM) was used to investigate synaptic plasticity and information storage capacity at medial perforant path synapses in adult hippocampal dentate gyrus in vivo. Induction of long-term potentiation (LTP...
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.1716189115
更新日期:2018-03-06 00:00:00
abstract::The conversion of cells from a normal phenotype to full malignancy apparently requires multiple genetic events. Efforts to reconstruct multistep tumorigenesis in cell culture have shown that two types of oncogenes (typified by HRAS and MYC) can cooperate to elicit complete transformation. Transformation of embryonic r...
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.85.12.4355
更新日期:1988-06-01 00:00:00
abstract::Most simian-human immunodeficiency viruses (SHIVs) bearing envelope (Env) glycoproteins from primary HIV-1 strains fail to infect rhesus macaques (RMs). We hypothesized that inefficient Env binding to rhesus CD4 (rhCD4) limits virus entry and replication and could be enhanced by substituting naturally occurring simian...
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.1606636113
更新日期:2016-06-14 00:00:00
abstract::In this report we examine the effects of chronic anaerobic exposure and subsequent reoxygenation on protein synthesis patterns in Chinese hamster ovary cells. It is observed by two-dimensional gel electrophoresis (isoelectric focusing/NaDodSO4/PAGE) that the transition from an atmospheric environment to an anaerobic s...
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.81.15.4843
更新日期:1984-08-01 00:00:00
abstract::Zfp57 is a maternal-zygotic effect gene that maintains genomic imprinting. Here we report that Zfp57 mutants exhibited a variety of cardiac defects including atrial septal defect (ASD), ventricular septal defect (VSD), thin myocardium, and reduced trabeculation. Zfp57 maternal-zygotic mutant embryos displayed more sev...
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.1415541112
更新日期:2015-04-21 00:00:00
abstract::The requirement for protein synthesis in the mechanism of a circadian pacemaker was investigated by using inhibitors of protein synthesis. Continuous treatment of the ocular circadian pacemaker of the mollusc Bulla gouldiana with anisomycin or cycloheximide substantially lengthened (up to 39 and 52 hr, respectively) 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.89.22.10862
更新日期:1992-11-15 00:00:00
abstract::Transfer RNA is one of the most richly modified biological molecules. Biosynthetic pathways that introduce these modifications are underexplored, largely because their absence does not lead to obvious phenotypes under normal growth conditions. Queuosine (Q) is a hypermodified base found in the wobble positions of tRNA...
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.1018636108
更新日期:2011-05-03 00:00:00
abstract::Programmed death-1 (PD-1) regulates T cell exhaustion during chronic infections. Blocking the PD-1:PD-ligand (PD-L) pathway reinvigorates exhausted CD8 T cells. Exactly how blocking PD-1:PD-L interactions improves T cell immunity, however, remains unclear. PD-1:PD-L blockade could reprogram all exhausted T cells to be...
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.0801497105
更新日期:2008-09-30 00:00:00
abstract::Sixteen hybridomas have been identified that secrete antibodies specific to horizontal cells in the carp retina. The hybridomas have been classified into three groups based on their antibody staining patterns: group I, staining associated with all horizontal cells; group II, staining associated with the most abundant ...
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.81.19.6255
更新日期:1984-10-01 00:00:00
abstract::Histone modifications are regarded as the most indispensible phenomena in epigenetics. Of these modifications, lysine methylation is of the greatest complexity and importance as site- and state-specific lysine methylation exerts a plethora of effects on chromatin structure and gene transcription. Notably, paramecium b...
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.1009911107
更新日期:2010-10-26 00:00:00
abstract::The H2O2-requiring ligninase of the basidiomycete Phanerochaete chrysosporium oxidatively cleaves both lignin and lignin model compounds between C alpha and C beta (C-1 and C-2) of their aliphatic side chains. Previous work has demonstrated a reaction mechanism by which ligninase oxidizes aromatic substrates to their ...
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.83.11.3708
更新日期:1986-06-01 00:00:00
abstract::Neutrophils are immune cells that bind to, engulf, and destroy bacterial and fungal pathogens in infected tissue, and their clearance by apoptosis is essential for the resolution of inflammation. Killing involves both oxidative and nonoxidative processes, the oxidative pathway requiring electrogenic production of supe...
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.0607914103
更新日期:2006-11-14 00:00:00
abstract::Serum from a patient (CO) with acute lymphoblastic leukemia was reactive in immunoadherence assays with autologous leukemia cells but not with autologous blood lymphocytes or bone marrow cells during complete remission. Extensive absorption tests with an array of leukemia cells and normal cells were performed in order...
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.80.8.2341
更新日期:1983-04-01 00:00:00
abstract::Aerobic respiration is a fundamental energy-generating process; however, there is cost associated with living in an oxygen-rich environment, because partially reduced oxygen species can damage cellular components. Organisms evolved enzymes that alleviate this damage and protect the intracellular milieu, most notably 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.1505315112
更新日期:2015-08-25 00:00:00
abstract::G-protein-coupled receptors (GPCRs) are key signaling molecules and are intensely studied. Whereas GPCRs recognizing small-molecules have been successfully targeted for drug discovery, protein-recognizing GPCRs, such as the chemokine receptors, claim few drugs or even useful small molecule reagents. This reflects both...
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.1120431109
更新日期:2012-04-03 00:00:00
abstract::Focally evoked calcium waves in astrocyte cultures have been thought to propagate by gap-junction-mediated intercellular passage of chemical signal(s). In contrast to this mechanism we observed isolated astrocytes, which had no physical contact with other astrocytes in the culture, participating in a calcium wave. Thi...
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.93.23.13268
更新日期:1996-11-12 00:00:00
abstract::Two mutants of Balb/c 3T3 cells defective in adhesiveness to substratum have been isolated. After exposure to a mutagen a cell population was treated with prostaglandin E1 and methylisobutylxanthine to elevate the cells 3':5'-cyclic AMP levels and adhesion to the substratum; then, loosley adherent cells were harvested...
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.73.2.544
更新日期:1976-02-01 00:00:00
abstract::We have isolated and analyzed a cDNA from the central nervous system of the mollusc Lymnaea stagnalis encoding a putative receptor, which might be a natural hybrid between two different classes of receptor proteins. Preceded by a signal peptide, two types of repeated sequences are present in the N-terminal part of 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.91.11.4816
更新日期:1994-05-24 00:00:00