Abstract:
:Functionally differentiated chicken macrophages were derived by in vitro differentiation of embryonic yolk sac cells and were characterized by several macrophage-specific cell markers. Uniform, infected, virus-producing cultures were obtained after exposure of these macrophages to avian myoblastosis virus (AMV), avian myelocytomatosis virus (MC29), myeloblastosis-associated virus (MAV-2), and Prague strain of Rous sarcoma virus (PR-B RSV). Both AMV and MC29 induced morphological transformation typical of the in vivo leukemias induced by these virus strains. Analysis of the expression of macrophage-specific markers in these two transformed cell types demonstrated that different markers of the mature macrophage were suppressed by each virus, even though the parental cell immediately preceding the transformation event was a mature macrophage in both cases. Cells infected with PR-B RSV and MAV-2 showed no observable difference from uninfected macrophages in terms of morphological characteristics, growth rate, or expression of the differentiated functions of macrophages. Ths system provides demonstrations of a cell type that produces infectious, transforming RSV but fails to respond by functional alterations induced by the transforming gene, src.
journal_name
Proc Natl Acad Sci U S Aauthors
Durban EM,Boettiger Ddoi
10.1073/pnas.78.6.3600subject
Has Abstractpub_date
1981-06-01 00:00:00pages
3600-4issue
6eissn
0027-8424issn
1091-6490journal_volume
78pub_type
杂志文章abstract::Investigations into the biophysical properties of single molecules traditionally involve well defined in vitro systems where parameters such as solvent viscosity and applied forces are known a priori. These systems provide means to develop models describing the polymers response to a variety of conditions, including 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.0812723106
更新日期:2009-06-09 00:00:00
abstract::Humans speak, monkeys grunt, and ducks quack. How do we come to know which vocalizations animals produce? Here we explore this question by asking whether young infants expect humans, but not other animals, to produce speech, and further, whether infants have similarly restricted expectations about the sources of vocal...
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.0906049106
更新日期:2009-11-03 00:00:00
abstract::Although it is known that the c-myc oncogene is rearranged in a head-to-head fashion with the immunoglobulin heavy chain locus in mouse plasmacytomas, it has not been clear whether the c-myc oncogene is translocated to the heavy chain locus on mouse chromosome 12 or whether the heavy chain locus is translocated to 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.82.12.4212
更新日期:1985-06-01 00:00:00
abstract::In contrast to observations in bacteria and fungi, frameshift mutations in bacteriophage T4 do not arise during genetic recombination. Nascent mutants, captured in the heterozygous condition, exhibit properties which indicate that the new lesions are located at the extreme tips of the chromosomes, and are segregated 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.65.3.617
更新日期:1970-03-01 00:00:00
abstract::Previous work has demonstrated a role for the E2F1 gene product in signaling apoptosis, both as a result of the deregulation of the Rb/E2F pathway as well as in response to DNA damage. We now show that the ability of cells to suppress the apoptotic potential of E2F1, as might occur during the course of normal cellular...
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.1831408100
更新日期:2003-09-16 00:00:00
abstract::Hyperapobetalipoproteinemia is defined as the combination of a normal low density lipoprotein (LDL) cholesterol in the face of an increased LDL apolipoprotein B (apoB) protein. To examine the physical basis for the apparent disproportion between LDL cholesterol and apoB characteristic of this syndrome, we used density...
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.80.21.6662
更新日期:1983-11-01 00:00:00
abstract::We introduce the concept of hybridization chain reaction (HCR), in which stable DNA monomers assemble only upon exposure to a target DNA fragment. In the simplest version of this process, two stable species of DNA hairpins coexist in solution until the introduction of initiator strands triggers a cascade of hybridizat...
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.0407024101
更新日期:2004-10-26 00:00:00
abstract::We determined the complete mtDNA sequence of the centipede Lithobius forficatus and found that only one of the 22 inferred tRNA genes encodes a fully paired aminoacyl acceptor stem. The other 21 genes encode tRNAs with up to five mismatches in these stems, and some of these overlap extensively with the downstream 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.250402997
更新日期:2000-12-05 00:00:00
abstract::RNA interference is an evolutionarily conserved process in which recognition of double-stranded RNA ultimately leads to posttranscriptional suppression of gene expression. This suppression is mediated by short (21- to 22-nt) small interfering RNAs (siRNAs), which induce degradation of mRNA based on complementary base ...
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.242594499
更新日期:2002-11-12 00:00:00
abstract::A convenient technique for the partial purification of large quantities of functional, poly(adenylic acid)-rich mRNA is described. The method depends upon annealing poly(adenylic acid)-rich mRNA to oligothymidylic acid-cellulose columns and its elution with buffers of low ionic strength. Biologically active rabbit glo...
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.69.6.1408
更新日期:1972-06-01 00:00:00
abstract::To test the hypothesis that the nonrandom organization of the contents of interphase nuclei represents a compartmentalization of function, we examined the relative, spatial relationship of small nuclear ribonucleoproteins (snRNPs) and of DNase I hypersensitive chromatin (DHC) in rat pheochromocytoma cells. In controls...
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.93.21.11646
更新日期:1996-10-15 00:00:00
abstract::The configuration of the heme-carbonyl group upon binding of carbon monoxide to sperm whale myoglobin (Mb) in crystals is evaluated on the basis of infrared spectroscopic methods. Multiplets of the totally symmetric C-O stretching mode are observed for the heme-bound ligand near 1933, 1944, and 1967 cm-1, correspondin...
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.76.12.6042
更新日期:1979-12-01 00:00:00
abstract::Serotonin (5-HT) controls a wide range of biological functions. In the brain, its implication as a neurotransmitter and in the control of behavioral traits has been largely documented. At the periphery, its modulatory role in physiological processes, such as the cardiovascular function, is still poorly understood. 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.2233056100
更新日期:2003-11-11 00:00:00
abstract::Rhesus monkeys were immunized by multiple inoculations with purified, disrupted, noninfectious simian immunodeficiency virus (SIV) in adjuvant. Immunized monkeys developed anti-SIV antibodies detectable by whole-virus ELISA and by immunoblot reactivity; these antibodies had weak neutralizing activity. One week after 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.86.16.6353
更新日期:1989-08-01 00:00:00
abstract::Tau is a highly soluble protein, yet it aggregates abnormally in Alzheimer's disease. Here, we address the question of proteolytic processing of tau and the nucleation of aggregates by tau fragments. We show in neuronal cell models that fragments of the repeat domain of tau containing mutations of FTDP17 (frontotempor...
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.0703676104
更新日期:2007-06-12 00:00:00
abstract::Measurements of auditory sensitivity in terms of the cochlear potentials were made in young specimens of three species of crocodilians, Caiman crocodilus and Alligator mississipiensis of the subfamily Alligatorinae and Crocodylus acutus of the subfamily Crocodylinae. These species show considerable similarity in 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.68.7.1498
更新日期:1971-07-01 00:00:00
abstract::ChIP coupled with microarray provides a powerful tool to determine in vivo binding profiling of transcription factors to deduce regulatory circuitries in mammalian cells. Aiming at improving the specificity and sensitivity of such analysis, we developed a new technology called ChIP-DSL using the DNA selection and liga...
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.0700715104
更新日期:2007-03-20 00:00:00
abstract::The search for technosignatures from hypothetical galactic civilizations is going through a new phase of intense activity. For the first time, a significant fraction of the vast search space is expected to be sampled in the foreseeable future, potentially bringing informative data about the abundance of detectable ext...
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.1808578115
更新日期:2018-10-16 00:00:00
abstract::DNA replication is a core biological process that occurs in prokaryotic cells at high speeds (∼1 nucleotide residue added per millisecond) and with high fidelity (fewer than one misincorporation event per 107 nucleotide additions). The ssDNA binding protein [gene product 32 (gp32)] of the T4 bacteriophage is a central...
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.1619819114
更新日期:2017-05-02 00:00:00
abstract::The relative abundance of individual proteins shared among clones of lymphocytes provides a meaningful basis for cellular classification. Twelve clones of T cells (obtained by limiting dilution) were analyzed by two-dimensional gel electrophoresis for polypeptide content and then evaluated by the computational techniq...
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.85.10.3565
更新日期:1988-05-01 00:00:00
abstract::The mechanism of nuclear DNA replication in radicles of germinating cotton (Gossypium barbadense) was investigated. Pulse-labeling with [(3)H]thymidine indicates that replication intermediates are of small molecular weight (4-10S) and behave as if single-stranded. Prolonged labeling indicates that intermediates are 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.73.9.3220
更新日期:1976-09-01 00:00:00
abstract::Alterations in the activity/levels of the extralarge G protein α-subunit (XLαs) are implicated in various human disorders, such as perinatal growth retardation. Encoded by GNAS, XLαs is partly identical to the α-subunit of the stimulatory G protein (Gsα), but the cellular actions of XLαs remain poorly defined. Followi...
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.1712670114
更新日期:2017-11-07 00:00:00
abstract::From what viruses the human immunodeficiency viruses (HIVs) originated is an extremely controversial question. To address this question, we have analyzed nucleotide sequences of simian immunodeficiency viruses (SIVs) and HIVs by using the techniques for understanding molecular evolution. In particular, we compared 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.87.11.4108
更新日期:1990-06-01 00:00:00
abstract::Ascorbic acid, at nontoxic concentrations, causes a substantial reduction in the ability of avian tumor viruses to replicate in both primary avian tendon cells and chicken embryo fibroblasts. The virus-infected cultures appear to be less transformed in the presence of ascorbic acid by the criteria of morphology, reduc...
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.77.5.2711
更新日期:1980-05-01 00:00:00
abstract::Murine fetal thymus lobes isolated from both normal and scid/scid mice can be colonized by donor cells from either human bone marrow or human umbilical cord blood in vitro. Subsequent organ culture results in a transient production of a few CD4+ CD8+ (double-positive) cells and then the accumulation of CD4+ or CD8+ (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.90.22.10778
更新日期:1993-11-15 00:00:00
abstract::Selective blockade of gene expression by designed small molecules is a fundamental challenge at the interface of chemistry, biology, and medicine. Transcription factors have been among the most elusive targets in genetics and drug discovery, but the fields of chemical biology and genetics have evolved to a point where...
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.1312473110
更新日期:2013-09-24 00:00:00
abstract::Hox genes encode transcription factors that control spatial patterning during embryogenesis. To date, downstream targets of Hox genes have proven difficult to identify. Here, we describe studies designed to identify target genes under the control of the murine transcription factor Hoxc8. We used a mouse 16,463 gene ol...
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.0409700102
更新日期:2005-02-15 00:00:00
abstract::Invading organisms may spread through local movements (giving rise to a diffusion-like process) and by long-distance jumps, which are often human-mediated. The local spread of invading organisms has been fit with varying success to models that couple local population growth with diffusive spread, but to date no quanti...
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.98.3.1095
更新日期:2001-01-30 00:00:00
abstract::Recent anatomical tracing studies have yielded substantial amounts of data on the areal connectivity underlying distributed processing in cortex, yet the fundamental principles that govern the large-scale organization of cortex remain unknown. Here we show that functional similarity between areas as defined by the pat...
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.1414153111
更新日期:2014-11-18 00:00:00
abstract::Apoptotic cells contain nuclear autoantigens that may initiate a systemic autoimmune response. To explore the mechanism of antibody binding to apoptotic cells, 3H9, a murine autoantibody with dual specificity for phospholipids and DNA, was used. H chain mutants of 3H9 were constructed, expressed as single-chain Fv (sc...
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.241510698
更新日期:2001-11-20 00:00:00