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::We present two methods to probe the energy landscape and motions of proteins in the context of molecular dynamics simulations of the helix-forming S-peptide of RNase A and the RNase A-3'-UMP enzyme-product complex. The first method uses the generalized ergodic measure to compute the rate of conformational space sampli...
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.90.3.809
更新日期:1993-02-01 00:00:00
abstract::The amplitude of the CO(2) seasonal cycle at the Mauna Loa Observatory (MLO) increased from the early 1970s to the early 1990s but decreased thereafter despite continued warming over northern continents. Because of its location relative to the large-scale atmospheric circulation, the MLO receives mainly Eurasian air m...
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.0611224104
更新日期:2007-03-13 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.0913112107
更新日期:2010-04-20 00:00:00
abstract::The liver provides for long-term energy needs of the body by converting excess carbohydrate into fat for storage. Insulin is one factor that promotes hepatic lipogenesis, but there is increasing evidence that glucose also contributes to the coordinated regulation of carbohydrate and fat metabolism in liver by mechanis...
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.0401516101
更新日期:2004-05-11 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.89.8.3473
更新日期:1992-04-15 00:00:00
abstract::The world's oceans are undergoing profound changes as a result of human activities. However, the consequences of escalating human impacts on marine mammal biodiversity remain poorly understood. The International Union for the Conservation of Nature (IUCN) identifies 25% of marine mammals as at risk of extinction, but ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.1121469109
更新日期:2012-02-28 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.1525665113
更新日期:2016-02-16 00:00:00
abstract::The herpes simplex virus DNA polymerase consists of two subunits--a catalytic subunit and an accessory subunit, UL42, that increases processivity. Mutations affecting the extreme C terminus of the catalytic subunit specifically disrupt subunit interactions and ablate virus replication, suggesting that new antiviral dr...
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.92.5.1456
更新日期:1995-02-28 00:00:00
abstract::Metastatic spread is the leading cause of cancer mortality. Breast cancer (BCa) metastatic recurrence can happen years after removal of the primary tumor. Here we show that Ubc13, an E2 enzyme that catalyzes K63-linked protein polyubiquitination, is largely dispensable for primary mammary tumor growth but is required ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2014-09-23 00:00:00
abstract::The etiology of Alzheimer disease is unclear. However, immunological aberrations have been suggested to be critical factors in the pathogenesis of this neurodegenerative disease. This study was carried out to investigate if cerebrospinal fluid (CSF) from Alzheimer disease patients contains antibodies that recognize sp...
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.84.24.9214
更新日期:1987-12-01 00:00:00
abstract::We have developed an in vitro transcription system that uses nuclei isolated from Lemna gibba G-3. The in vitro transcripts include sequences homologous to hybridization probes for the small subunit of ribulose-1,5-bisphosphate carboxylase [3-phospho-D-glycerate carboxy-lyase (dimerizing), EC 4.1.1.39], the light-harv...
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.81.4.1112
更新日期:1984-02-01 00:00:00
abstract::The binding of transcription factors (TFs) to DNA controls most aspects of cellular function, making the understanding of their binding kinetics imperative. The standard description of bimolecular interactions posits that TF off rates are independent of TF concentration in solution. However, recent observations have 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.1701884114
更新日期:2017-04-18 00:00:00
abstract::The type specimen for Australopithecus africanus (Taung) includes a natural endocast that reproduces most of the external morphology of the right cerebral hemisphere and a fragment of fossilized face that articulates with the endocast. Despite the fact that Taung died between 3 and 4 y of age, the endocast reproduces ...
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.1119752109
更新日期:2012-05-29 00:00:00
abstract::The fossil record of land plants is an obvious source of information on the dynamics of mass extinctions in the geological past. In conjunction with the end-Permian ecological crisis, approximately 250 million years ago, palynological data from East Greenland reveal some unanticipated patterns. We document the signifi...
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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更新日期:2001-07-03 00:00:00
abstract::Eukaryotic DNA replication fidelity relies on the concerted action of DNA polymerase nucleotide selectivity, proofreading activity, and DNA mismatch repair (MMR). Nucleotide selectivity and proofreading are affected by the balance and concentration of deoxyribonucleotide (dNTP) pools, which are strictly regulated by 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.1618714114
更新日期:2017-05-30 00:00:00
abstract::The temporal and spatial patterns of floral determination in cultured internode segments of Nicotiana tabacum L. cv. Wisconsin 38 were investigated. Segments from internodes, when cultured on hormone-free medium, either produced some de novo floral shoots or produced only vegetative shoots. Segments that produced some...
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.84.9.2790
更新日期:1987-05-01 00:00:00
abstract::Plant soil specialists contribute greatly to global diversity; however, the ecoevolutionary forces responsible for generating this diversity are poorly understood. We integrate molecular phylogenies with descriptive and experimental ecological data, creating a powerful framework with which to elucidate forces driving ...
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.1409242111
更新日期:2014-10-21 00:00:00
abstract::We have isolated rat brain cDNA clones encoding AE2, a homologue of the erythrocyte anion exchanger, band 3 (AE1). Immunocytochemistry and in situ hybridization reveal that, in brain, AE2 expression is restricted to the basolateral membrane of the choroid plexus epithelium. Expression of a full-length mouse AE2 cDNA i...
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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更新日期:1990-07-01 00:00:00
abstract::A method to identify 5-methylcytosine (m5Cyt) in DNA immobilized on nitrocellulose paper by using antibody against m5Cyt raised in rabbits is described. Immobilized restriction fragments of DNA are incubated first with purified antibody against m5Cyt and then with goat anti-rabbit IgG labeled with 125I. Restriction fr...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1980-06-01 00:00:00
abstract::Periodical cicadas are well known for their prime-numbered life cycles (17 and 13 years) and their mass periodical emergences. The origination and persistence of prime-numbered cycles are explained by the hybridization hypothesis on the basis of their lower likelihood of hybridization with other cycles. Recently, we s...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2009-06-02 00:00:00
abstract::I summarize recent computational and experimental work that addresses the inherent variability in the synaptic and intrinsic conductances in normal healthy brains and shows that multiple solutions (sets of parameters) can produce similar circuit performance. I then discuss a number of issues raised by this observation...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
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更新日期:2011-09-13 00:00:00
abstract::Three distinct endosomal fractions were isolated in high purity from livers of estradiol-treated rats. Each fraction had characteristic physical and ultrastructural properties, but the lipid composition and major proteins of their membranes were similar and differed from those derived from the Golgi apparatus. Injecte...
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.84.19.6785
更新日期:1987-10-01 00:00:00
abstract::Magnetic interactions between dissolved oxygen and nitroxide radical spin probes lead to broadening of the ESR lines. We have used a closed-chamber method based on this property to determine the maximum rate of O2 uptake per cell (Vmax per cell) in cultured mammalian cells. A suitable spin probe and a cell suspension ...
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.79.4.1166
更新日期:1982-02-01 00:00:00
abstract::The mitochondrial uniporter is a Ca2+-channel complex resident within the organelle's inner membrane. In mammalian cells the uniporter's activity is regulated by Ca2+ due to concerted action of MICU1 and MICU2, two paralogous, but functionally distinct, EF-hand Ca2+-binding proteins. Here we present the X-ray structur...
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.1817759116
更新日期:2019-02-26 00:00:00
abstract::Before they even speak, infants become attuned to the sounds of the language(s) they hear, processing native phonetic contrasts more easily than nonnative ones. For example, between 6 to 8 mo and 10 to 12 mo, infants learning American English get better at distinguishing English and [l], as in "rock" vs. "lock," relat...
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.2001844118
更新日期:2021-02-09 00:00:00
abstract::Voltage gating of hyperpolarization-activated cation (HCN) channels is potentiated by direct binding of cAMP to a cytoplasmic cAMP-sensing domain (CSD). When unliganded, the CSD inhibits hyperpolarization-dependent opening of the HCN channel gate; cAMP binding relieves this autoinhibition so that opening becomes more ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2011-01-11 00:00:00
abstract::Transmembrane (TM) domains of integral membrane proteins are generally thought to be helical. However, a Gly-Pro sequence within the TM domain of the insulin receptor is predicted to act as a helix breaker. CD analyses of model TM peptides in a lipid-like environment show that substitution of Gly and Pro by Ala enhanc...
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.90.12.5762
更新日期:1993-06-15 00:00:00
abstract::The helicity in water has been determined for several series of alanine-rich peptides that contain single lysine residues and that are N-terminally linked to a helix-inducing and reporting template termed Ac-Hel1. The helix-propagating constant for alanine (sAla value) that best fits the properties of these peptides l...
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.93.9.4025
更新日期:1996-04-30 00:00:00
abstract::From a flounder pituitary cDNA library, cDNA clones encoding a 28-kDa glycoprotein produced by the pars intermedia of the pituitary were isolated and characterized. Nucleotide sequencing demonstrated a precursor of the 28-kDa protein, which consisted of 231 amino acid residues, to be cleaved into a signal peptide (24 ...
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.87.11.4330
更新日期:1990-06-01 00:00:00
abstract::Due to intrinsic aggressiveness and lack of effective therapies, prognosis of pancreatic cancer remains dismal. Because the only molecular targeted drug approved for pancreatic ductal adenocarcinoma is a kinase inhibitor specific to the epidermal growth factor receptor (EGFR), and this receptor collaborates with anoth...
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.1313857110
更新日期:2013-09-17 00:00:00