Abstract:
:Gene transfer into early embryos is a powerful methodology for unraveling the molecular bases of developmental processes. One can attempt to minimize widespread effects of an exogenous gene by using tissue- or region-specific promoters in the few instances where they are available. We have developed a method that bypasses the requirement for specific targeting sequences to achieve regionally restricted gene transfer. Intraspecific chimeras have been created by transplantation of restricted portions of a chicken embryo from a donor strain to a host strain. The donor cells are infectable with a recombinant retroviral vector that carries the exogenous gene, whereas the host cells are not. We have demonstrated the feasibility of this approach using a histochemically distinct reporter gene, human placental alkaline phosphatase. The expression of retrovirally transduced alkaline phosphatase was limited to a transplanted hemiprosencephalon (forebrain and eye) in embryonic chickens. This technique can be applied to many other organ systems during avian embryogenesis to test the function(s) of molecules that are normally controlled through spatial and/or temporal regulation, such as many of the growth factor receptors or homeobox-containing proteins.
journal_name
Proc Natl Acad Sci U S Aauthors
Fekete DM,Cepko CLdoi
10.1073/pnas.90.6.2350subject
Has Abstractpub_date
1993-03-15 00:00:00pages
2350-4issue
6eissn
0027-8424issn
1091-6490journal_volume
90pub_type
杂志文章abstract::We report free-standing atomic crystals that are strictly 2D and can be viewed as individual atomic planes pulled out of bulk crystals or as unrolled single-wall nanotubes. By using micromechanical cleavage, we have prepared and studied a variety of 2D crystals including single layers of boron nitride, graphite, sever...
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.0502848102
更新日期:2005-07-26 00:00:00
abstract::A rigorous numerical test of a hypothetical mechanism of a molecular motor should model explicitly the diffusive motion of the motor's degrees of freedom as well as the transition rates between the motor's chemical states. We present such a Brownian dynamics, mechanochemcial model of the coarse-grain structure 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.0908192106
更新日期:2009-10-27 00:00:00
abstract::The forebrain cholinergic system promotes higher brain function in part by signaling through the M(1) muscarinic acetylcholine receptor (mAChR). During Alzheimer's disease (AD), these cholinergic neurons degenerate, therefore selectively activating M(1) receptors could improve cognitive function in these patients whil...
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.0900903106
更新日期:2009-09-15 00:00:00
abstract::Although most nuclear hormone receptors are ligand-dependent transcriptional activators, certain members of this superfamily, such as thyroid hormone receptor (TR) and retinoic acid receptor (RAR), are involved in transcriptional repression. The silencing function of these receptors has been localized to the ligand bi...
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.92.25.11691
更新日期:1995-12-05 00:00:00
abstract::Tetrahymena ribozymes hold promise for repairing genetic disorders but are largely limited by their modest splicing efficiency and low production of final therapeutic proteins. Ribozyme evolution in intact living mammalian cells would greatly facilitate the discovery of new ribozyme variants with high in vivo activity...
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.2036553100
更新日期:2003-12-09 00:00:00
abstract::Multiple resistance and pH adaptation (Mrp) complexes are sophisticated cation/proton exchangers found in a vast variety of alkaliphilic and/or halophilic microorganisms, and are critical for their survival in highly challenging environments. This family of antiporters is likely to represent the ancestor of cation pum...
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.2006276117
更新日期:2020-12-08 00:00:00
abstract::Hookworms are hematophagous nematodes that infect a wide range of mammalian hosts, including humans. There has been speculation for nearly a century as to the identity of the anticoagulant substances) used by these organisms to subvert host hemostasis. Using molecular cloning, we describe a family of potent small prot...
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.93.5.2149
更新日期:1996-03-05 00:00:00
abstract::Cells from the spleens and thymuses of BALB/c mice whose Moloney sarcoma virus (MSV)-induced, primary sarcomas have regressed 2-3 months earlier ("MSV regressors") or are in the process of regressing can, when adoptively transferred to syngeneic mice given MSV at the age of 20 days, prevent the natural regression of 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.76.10.5294
更新日期:1979-10-01 00:00:00
abstract::The requirement and influence of the peripheral nervous system on tissue replacement in mammalian appendages remain largely undefined. To explore this question, we have performed genetic lineage tracing and clonal analysis of individual cells of mouse hind limb tissues devoid of nerve supply during regeneration 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.1410097111
更新日期:2014-07-08 00:00:00
abstract::OspA (outer surface protein A) is an abundant immunogenic lipoprotein of the Lyme disease spirochete Borrelia burgdorferi. The crystal structure of a soluble recombinant form of OspA was solved in a complex with the Fab fragment of mouse monoclonal antibody 184.1 and refined to a resolution of 1.9 A. OspA has a repeti...
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.94.8.3584
更新日期:1997-04-15 00:00:00
abstract::The pleiotropic effect of the sickle gene suggests that factors in addition to polymerization of the mutant gene product might be involved in sickle disease pathobiology. We have examined rates of heme transfer to hemopexin from hemoglobin in dilute aqueous solution (0.5 mg of Hb per ml) at 37 degrees C. HbO2 S loses ...
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.85.1.237
更新日期:1988-01-01 00:00:00
abstract::A light form of DNA ligase (EC 6.5.1.2), the only form present in oocytes of the axolotl (Ambystoma mexicanum), has been shown to be replaced by a heavy form of the enzyme when the egg enters cleavage. This early biochemical event has been assumed to rely on direct nuclear input. Sucrose gradient analysis permits disc...
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.80.11.3368
更新日期:1983-06-01 00:00:00
abstract::Our group recently demonstrated that autoimmune T cells directed against central nervous system-associated myelin antigens protect neurons from secondary degeneration. We further showed that the synthetic peptide copolymer 1 (Cop-1), known to suppress experimental autoimmune encephalomyelitis, can be safely substitute...
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.041609498
更新日期:2001-03-13 00:00:00
abstract::Bacteriophage 434 encodes a repressor that, like bacteriophage lambda repressor, both activates and represses transcription. As in the lambda chromosome, a region of the 434 chromosome, called the right operator, contains three repressor binding sites (OR1, OR2, and OR3) that mediate these effects on two adjacent prom...
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.83.24.9353
更新日期:1986-12-01 00:00:00
abstract::The amyloid beta-protein precursor (AbetaPP) is best known as the parent molecule to the amyloid beta-peptide that accumulates in the brains of patients with Alzheimer's disease. Secreted isoforms of AbetaPP that contain the Kunitz proteinase inhibitor domain are analogous to the previously identified cell-secreted pr...
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.0507798102
更新日期:2005-12-13 00:00:00
abstract::HIV-1 infection in the brain induces neuronal apoptosis leading to HIV-associated dementia. To explore the underlying mechanism, we developed a murine model by using human peripheral blood mononuclear cell (PBMC)-transplanted nonobese diabetic (NOD)-severe combined immunodeficiency (SCID) (hu-PBMC-NOD-SCID) mice. Admi...
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.2628048100
更新日期:2003-03-04 00:00:00
abstract::The conserved Ndc80 complex is an essential microtubule-binding component of the kinetochore. Recent findings suggest that the Ndc80 complex influences microtubule dynamics at kinetochores in vivo. However, it was unclear if the Ndc80 complex mediates these effects directly, or by affecting other factors localized at ...
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.1209615109
更新日期:2012-10-02 00:00:00
abstract::Rats were raised after weaning on a vitamin D-deficient diet which used whole wheat and casein as the major protein source. For at least the first year of life, plasma calcium concentrations of these rats were the same as those of vitamin D-replete rats, and the rate of growth was normal for at least 6 months. The fol...
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.79.15.4791
更新日期:1982-08-01 00:00:00
abstract::Climate change and resource exploitation have been shown to modify the importance of bottom-up and top-down forces in ecosystems. However, the resulting pattern of trophic control in complex food webs is an emergent property of the system and thus unintuitive. We develop a statistical nondeterministic model, capable o...
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.1621037114
更新日期:2017-02-21 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.031587498
更新日期:2001-02-13 00:00:00
abstract::The emergence of bacterial multidrug resistance to antibiotics threatens to cause regression to the preantibiotic era. Here we present the crystal structure of the large ribosomal subunit from Staphylococcus aureus, a versatile Gram-positive aggressive pathogen, and its complexes with the known antibiotics linezolid a...
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.1517952112
更新日期:2015-10-27 00:00:00
abstract::Fast-atom bombardment mass spectrometry was used to follow the time course of disulfide bond formation during in vitro refolding of recombinant human macrophage-colony-stimulating factor. The content of iodoacetamide-alkylated half-cystines in proteolytic peptides of trapped refolding intermediates collected at 0, 6, ...
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.91.13.5868
更新日期:1994-06-21 00:00:00
abstract::Mutational activation of the Ras oncogene products (H-Ras, K-Ras, and N-Ras) is frequently observed in human cancers, making them promising anticancer drug targets. Nonetheless, no effective strategy has been available for the development of Ras inhibitors, partly owing to the absence of well-defined surface pockets 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.1217730110
更新日期:2013-05-14 00:00:00
abstract::Several authors have considered Markov processes defined by the motion of a particle on a fixed line with a random velocity(1, 6, 8, 10) or a random diffusivity.(5, 12) A "random evolution" is a natural but apparently new generalization of this notion. In this note we hope to show that this concept leads to simple and...
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.62.2.305
更新日期:1969-02-01 00:00:00
abstract::The redox siblings nitroxyl (HNO) and nitric oxide (NO) have often been assumed to undergo casual redox reactions in biological systems. However, several recent studies have demonstrated distinct pharmacological effects for donors of these two species. Here, infusion of the HNO donor Angeli's salt into normal dogs res...
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.1430507100
更新日期:2003-08-05 00:00:00
abstract::The structural analysis of the Fab' fragment of human myeloma immunoglobulin IgGl(lambda) New has been extended to a nominal resolution of 2.0 A. Each of the structural subunits corresponding to the variable and to the constant homology regions of the light and heavy chains contains two irregular beta-sheets which are...
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.71.9.3440
更新日期:1974-09-01 00:00:00
abstract::A genomic region on distal mouse chromosome 1 and its syntenic human counterpart 1q23-42 show strong evidence of harboring lupus susceptibility genes. We found evidence of linkage at 1q32.2 in a targeted genome scan of 1q21-43 in 126 lupus multiplex families containing 151 affected sibpairs (nonparametric linkage scor...
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.0609101104
更新日期:2007-03-06 00:00:00
abstract::Congenital osteopetrosis in the mutant rat "op" is accompanied by early atrophy of the thymus gland. The response of thymocytes to concanavalin A and phytohemagglutinin P was greatly diminished at age 28 days, even before pronounced thymic atrophy could be detected. The response of spleen cells to mitogens that stimul...
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.74.1.339
更新日期:1977-01-01 00:00:00
abstract::The potential benefits of autonomous systems are obvious. However, there are still major issues to be dealt with before developing such systems becomes a commonplace engineering practice, with accepted and trustworthy deliverables. We argue that a solid, evolving, publicly available, community-controlled foundation fo...
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.2003162117
更新日期:2020-07-28 00:00:00
abstract::We examined human immunodeficiency virus (HIV) production in cultured mononuclear cells from 36 seropositive homosexual males. Production was detected by using an HIV p24 antigen ELISA assay in blood mononuclear cells in 54% of asymptomatic, 71% of acquired immunodeficiency syndrome (AIDS)-related complex, and 100% 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.86.2.675
更新日期:1989-01-01 00:00:00