Abstract:
:Genes that are unexpressed in somatic cells have been activated by injecting cultured cell nuclei of the frog Xenopus laevis into oocytes of the newt Pleurodeles waltlii. The genes that were activated are normally expressed in oocytes but not in cultured cells. Conversely, genes that are normally expressed in cultured cells but not in oocytes became inactive when cultured cell nuclei were injected into oocytes. These changes in gene activity were detected by two-dimensional gel electrophoresis of proteins synthesized by oocytes injected with nuclei. Controls, which included the use of alpha-amanitin, showed that these changes in protein synthesis are dependent on gene transcription. We conclude that genes that become inactive during cell differentiation can be reactivated, in the absence of cell division, by normal components of oocyte cytoplasm.
journal_name
Proc Natl Acad Sci U S Aauthors
De Robertis EM,Gurdon JBdoi
10.1073/pnas.74.6.2470subject
Has Abstractpub_date
1977-06-01 00:00:00pages
2470-4issue
6eissn
0027-8424issn
1091-6490journal_volume
74pub_type
杂志文章abstract::Molecules of transfer RNA (tRNA) typically contain four stems composed of Watson-Crick (W-C) base pairs and infrequent mispairs such as G-U and A-C. The latter mispairs are fundamental units of RNA secondary structure found in nearly every class of RNA and are nearly isomorphic to W-C pairs. Therefore, they often 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.0600592103
更新日期:2006-03-21 00:00:00
abstract::Plastid development in seedlings of Arabidopsis thaliana is affected by the transfer of (1)O(2)-mediated retrograde signals from the plastid to the nucleus and changes in nuclear gene expression during late embryogenesis. The potential impact of these mechanisms on plastid differentiation is maintained throughout seed...
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.0901315106
更新日期:2009-06-16 00:00:00
abstract::Rabbit articular chondrocytes synthesize type II collagen [3alpha(1)(II)] in vivo and type I collagen [2alpha(1)(I).alpha(2)] in monolayer cultures. In suspension culture the nature of phenotype depends on extracellular Ca(2+). The relationship of Ca(2+) and 3':5'-cyclic AMP (cAMP) in regulation of collagen synthesis ...
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.74.9.3864
更新日期:1977-09-01 00:00:00
abstract::Phylogenies describe the origins and history of species. However, they can also help to predict species' fates and so can be useful tools for managing the future of biodiversity. This article starts by sketching how phylogenetic, geographic, and trait information can be combined to elucidate present mammalian diversit...
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.0801917105
更新日期:2008-08-12 00:00:00
abstract::We have measured the opioid receptor reserve in the guinea pig ileum myenteric plexus by means of the site-directed alkylating agent, beta-chlornaltrexamine. Treatment of the tissue with low (less than 10 nM) concentrations of beta-chlornaltrexamine caused a parallel shift of the log concentration-response curves for ...
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.81.22.7253
更新日期:1984-11-01 00:00:00
abstract::Ghrelin is a newly discovered peptide and an endogenous ligand for growth hormone (GH) secretagogue (GHS) receptor. It has been shown to possess various central and peripheral effects, including GH secretion, food intake, and gastric and cardiac effects. Ghrelin and the GHS receptor are expressed also in pancreatic is...
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.0502470102
更新日期:2006-01-24 00:00:00
abstract::Oxygen isotherms of human hemoglobin measured in distilled water and in solutions of sodium chloride in the concentration range from 0.02 to 3.0 M indicate that the oxygen affinity decreases up to about 1 M salt and then begins to increase. The isotherms obtained in the range from 0.02 to 0.6 M sodium chloride, at 37 ...
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.74.10.4135
更新日期:1977-10-01 00:00:00
abstract::Cell surface receptor membrane localization is strongly dependent on protein-protein interactions often involving regulation by phosphorylation/dephosphorylation of the intracellular domains of membrane proteins. The present study was carried out to identify metabotropic glutamate receptor (mGluR) 3 regulatory binding...
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.2136600100
更新日期:2003-12-23 00:00:00
abstract::The rise of inorganic-biological hybrid organisms for solar-to-chemical production has spurred mechanistic investigations into the dynamics of the biotic-abiotic interface to drive the development of next-generation systems. The model system, Moorella thermoacetica-cadmium sulfide (CdS), combines an inorganic semicond...
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.1610554113
更新日期:2016-10-18 00:00:00
abstract::Carbohydrate-based vaccines have shown therapeutic efficacy for infectious disease and cancer. The mushroom Ganoderma lucidum (Reishi) containing complex polysaccharides has been used as antitumor supplement, but the mechanism of immune response has rarely been studied. Here, we show that the mice immunized with a l-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.1312457110
更新日期:2013-08-20 00:00:00
abstract::Oxidation of molecular hydrogen catalyzed by [NiFe] hydrogenases is a widespread mechanism of energy generation among prokaryotes. Biosynthesis of the H2-oxidizing enzymes is a complex process subject to positive control by H2 and negative control by organic energy sources. In this report we describe a novel signal tr...
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.95.21.12474
更新日期:1998-10-13 00:00:00
abstract::Polymersomes, which are stable and robust vesicles made of block copolymer amphiphiles, are good candidates for drug carriers or micro/nanoreactors. Polymer chemistry enables almost unlimited molecular design of responsive polymersomes whose degradation upon environmental changes has been used for the slow release 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.0813157106
更新日期:2009-05-05 00:00:00
abstract::During brain maturation, the occurrence of the extracellular matrix (ECM) terminates juvenile plasticity by mediating structural stability. Interestingly, enzymatic removal of the ECM restores juvenile forms of plasticity, as for instance demonstrated by topographical reconnectivity in sensory pathways. However, to wh...
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.1310272111
更新日期:2014-02-18 00:00:00
abstract::Host species have evolved mechanisms that can inhibit pathogen replication even after a cell has been successfully invaded. Here we show that tripartite-motif protein 21 (TRIM21), a ubiquitously expressed E3 ubiquitin ligase that targets viruses inside the cytosol, protects mice against fatal viral infection. Upon inf...
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.1301918110
更新日期:2013-07-23 00:00:00
abstract::Antibodies to the insulin receptor were prepared in BALB/c mice by immunization with IM-9 human lymphocytes, a cell type that has a large number of plasma membrane insulin receptors. The spleens of these mice were then removed, and their lymphocytes were fused to a mouse myeloma cell line, FO cells. After screening ov...
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.79.23.7312
更新日期:1982-12-01 00:00:00
abstract::With threats to nature becoming increasingly prominent, in order for biodiversity levels to persist, there is a critical need to improve implementation of conservation measures. In the oceans, the surveillance of fisheries is complex and inadequate, such that quantifying and locating nondeclared and illegal fisheries ...
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.1915499117
更新日期:2020-02-11 00:00:00
abstract::Although much is known about the underlying mechanisms of p53 activity and regulation, the factors that influence the diversity and duration of p53 responses are not well understood. Here we describe a unique mode of p53 regulation involving alternative splicing of the TP53 gene. We found that the use of an alternativ...
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.1321640111
更新日期:2014-08-12 00:00:00
abstract::We have used electron microscopy to examine freshly isolated Salmonella typhimurium and Escherichia coli basal flagellar fragments, purified without resort to extremes of pH or ionic strength. Such fragments contain the large bell-like basal structures visualized recently in freeze-substituted or fixed preparations. W...
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.89.13.5956
更新日期:1992-07-01 00:00:00
abstract::The assembly of clathrin-coated vesicles on Golgi membranes is initiated by the GTP-binding protein ADP ribosylation factor (ARF), which generates high-affinity membrane-binding sites for the heterotetrameric AP-1 adaptor complex. Once bound, the AP-1 recruits clathrin triskelia, which polymerize to form the coat. We ...
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.96.9.5013
更新日期:1999-04-27 00:00:00
abstract::Recently, p53 was demonstrated to affect the expression of the insulin-like growth factor 1 receptor (IGF-1R), a receptor tyrosine kinase that plays a crucial role in growth and survival of cancer cells. However, the underlying mechanisms for interaction between p53 and IGF-1R are still not fully understood. One of th...
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.1431613100
更新日期:2003-07-08 00:00:00
abstract::On a planet experiencing global environmental change, the governance of natural resources depends on sustained collective action by diverse populations. Engaging in such collective action can only build upon the foundation of human cognition in social-ecological settings. To help understand this foundation, we assess ...
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.1915824117
更新日期:2020-04-07 00:00:00
abstract::The photoproduct of carbon monoxide myoglobin generated at 4 K and lower has a resonance Raman spectrum characteristic of a high-spin heme but in which the high-frequency core size-sensitive lines are at lower frequency than those in the deoxy preparation. Such differences are not detected in the photoproduct generate...
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.83.5.1310
更新日期:1986-03-01 00:00:00
abstract::The rate of leucine incorporation into a specific estrogen-induced protein of immature rat isolated by gel electrophoresis declines rapidly between 2-4 hr after estrogen stimulation in vivo followed by incubation in vitro. Actinomycin D present during the in vitro phase prevents this decline, and elicits a "superinduc...
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.70.1.18
更新日期:1973-01-01 00:00:00
abstract::The spindle checkpoint ensures the accuracy of chromosome segregation during mitosis. The protein serine/threonine kinase, Mps1, is a critical component of the spindle checkpoint in human cells and regulates the kinetochore localization of key checkpoint proteins. The kinase activity of Mps1 is required for the spindl...
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.0710519105
更新日期:2007-12-18 00:00:00
abstract::Single-stranded DNA oligonucleotides can achieve targeted base-pair substitution with modest efficiency but high precision. We show that "oligo targeting" can be used effectively to study missense mutations in DNA mismatch repair (MMR) genes. Inherited inactivating mutations in DNA MMR genes are causative for the canc...
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.1520813113
更新日期:2016-04-12 00:00:00
abstract::The first definitive/adult-type hematopoietic stem cells (HSCs) in the mouse aorta-gonad-mesonephros region emerge between embryonic days 10.5 and 11.5. The discovery of clusters of hematopoietic cells on the ventral luminal surface of the dorsal aorta in various vertebrate species has led to speculation that the floo...
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.0700984104
更新日期:2007-05-29 00:00:00
abstract::Seawater Mg:Ca and Sr:Ca ratios are biogeochemical parameters reflecting the Earth-ocean-atmosphere dynamic exchange of elements. The ratios' dependence on the environment and organisms' biology facilitates their application in marine sciences. Here, we present a measured single-laboratory dataset, combined with previ...
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.1918943117
更新日期:2020-09-08 00:00:00
abstract::Extracts of cultured human leukemic tissues increased the spleen focus-forming activity of Friend leukemia virus preparations in BALB/c and other partially resistant mice. Such mice carry the Fv-1(b) gene, which inhibits the expression of helper virus indigenous to the Friend virus complex, and allows co-infecting leu...
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.68.10.2391
更新日期:1971-10-01 00:00:00
abstract::To some extent, the genetic theory of adaptive evolution in bacteria is a simple extension of that developed for sexually reproducing eukaryotes. In other, fundamental ways, the process of adaptive evolution in bacteria is quantitatively and qualitatively different from that of organisms for which recombination is an ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.97.13.6981
更新日期:2000-06-20 00:00:00
abstract::Parathyroid hormone (PTH) is central to calcium homeostasis and bone maintenance in vertebrates, and as such it has been used for treating osteoporosis. It acts primarily by binding to its receptor, PTH1R, a member of the class B G protein-coupled receptor (GPCR) family that also includes receptors for glucagon, calci...
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.0801027105
更新日期:2008-04-01 00:00:00