Abstract:
:Specific rearrangement of internal chromosomal regions occurs during development of the somatic macronucleus in Tetrahymena thermophila and results in elimination of germ-line (micronuclear) DNA sequences. The timing and mechanism of genome rearrangement within one particular 9.3-kilobase region, which contains three distinct eliminated sequences, were investigated. Portions of this cloned region were used as probes in Southern hybridization experiments to analyze DNA from developing macronuclei (anlagen). All three deletions were found to occur predominantly within a 2-hr time period in which the nuclear DNA contents increased from 4C to 8C (1C represents the amount of DNA present in a haploid genome). The three deletion events can occur independently because intermediate forms, having sustained one or two deletions, were detected. One of the deletions occurs in two alternative ways, resulting in two equally abundant products of different size. Because reciprocal products expected from unequal sister chromatid exchange were not detected, an intramolecular DNA splicing mechanism is suggested.
journal_name
Proc Natl Acad Sci U S Aauthors
Austerberry CF,Allis CD,Yao MCdoi
10.1073/pnas.81.23.7383subject
Has Abstractpub_date
1984-12-01 00:00:00pages
7383-7issue
23eissn
0027-8424issn
1091-6490journal_volume
81pub_type
杂志文章abstract::We have engineered the ecdysone-inducible mammalian expression system for general retroviral delivery to cultured mammalian cells. We inducibly expressed PTEN in the glioblastoma cell line, U87MG, lacking this gene. Because nearly all cells are recruited on induction, we find both up- and down-regulated genes by cDNA ...
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.221450598
更新日期:2001-11-06 00:00:00
abstract::Hepatitis C virus subverts liver-specific microRNA, miR-122, to upregulate viral RNA abundance in both infected cultured cells and in the liver of infected chimpanzees. These findings have identified miR-122 as an attractive antiviral target. Thus, it is imperative to know whether a distinct functional complex exists ...
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.1012464108
更新日期:2011-02-22 00:00:00
abstract::Aggression is a universal social behavior important for the acquisition of food, mates, territory, and social status. Aggression in Drosophila is context-dependent and can thus be expected to involve inputs from multiple sensory modalities. Here, we use mechanical disruption and genetic approaches in Drosophila melano...
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.1605946114
更新日期:2017-02-21 00:00:00
abstract::The high-affinity receptor for human granulocyte/macrophage colony-stimulating factor (hGM-CSF) is composed of two subunits, alpha and beta. The alpha subunit binds GM-CSF with low affinity, whereas the beta subunit does not bind GM-CSF by itself. The alpha and beta subunits together form the high-affinity GM-CSF rece...
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.88.12.5082
更新日期:1991-06-15 00:00:00
abstract::The genome of a thermophilic fungus, Thermomyces lanuginosus, contains a tandemly arranged cluster of sequences that are approximately equal to 50% homologous with the cytoplasmic 5S RNA and that are selectable by hybridization techniques. Unlike typical pseudogenes, these sequences are not truncated; rather, they bea...
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.81.6.1768
更新日期:1984-03-01 00:00:00
abstract::Emerging evidence suggests that transforming growth factor-beta (TGF-beta) is an important mediator of diabetic nephropathy. We showed previously that short-term treatment with a neutralizing monoclonal anti-TGF-beta antibody (alphaT) in streptozotocin-diabetic mice prevents early changes of renal hypertrophy and incr...
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.120055097
更新日期:2000-07-05 00:00:00
abstract::The identity of the oldest lineage of monocotyledons is a subject of debate. Alternative interpretations of morphological homologies are variously consistent with proposals that species of Alismatanae, Dioscoreales, or Melanthiales were the earliest descendants of the first monocotyledons. We present phylogenetic anal...
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.90.10.4641
更新日期:1993-05-15 00:00:00
abstract::Malignant B lymphocytes from several patients with chronic lymphocytic leukemia (CLL) were examined for reactivity with murine monoclonal antibody 17.109. This antibody, prepared against the rheumatoid factor (RF) paraprotein Sie, recognizes a crossreactive idiotype on 48% of human IgM RF paraproteins, but does not re...
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.84.9.2916
更新日期:1987-05-01 00:00:00
abstract::Transgenic mice expressing the Pim-1 kinase are predisposed to develop T-cell lymphomas with a long latency period of about 7-9 months. However, the exact functional basis of the oncogenic activity of Pim-1 remains obscure. C57BL/6 mice homozygous for the lpr mutation develop a well-described lymphoproliferative syndr...
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.90.22.10734
更新日期:1993-11-15 00:00:00
abstract::Bt toxins derived from the arthropod bacterial pathogen Bacillus thuringiensis are widely used for insect control as insecticides or in transgenic crops. Bt resistance has been found in field populations of several lepidopteran pests and in laboratory strains selected with Bt toxin. Widespread planting of crops expres...
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.1120698109
更新日期:2012-06-19 00:00:00
abstract::Early forms of the genetic code likely generated "statistical" proteins, with similar side chains occupying the same sequence positions at different ratios. In this scenario, groups of related side chains were treated by aminoacyl-tRNA synthetases as a single molecular species until a discrimination mechanism develope...
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.2136794100
更新日期:2003-12-23 00:00:00
abstract::Protein aggregation is a hallmark of many diseases, including amyotrophic lateral sclerosis (ALS), where aggregation of Cu/Zn superoxide dismutase (SOD1) is implicated in causing neurodegeneration. Recent studies have suggested that destabilization and aggregation of the most immature form of SOD1, the disulfide-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.0913021108
更新日期:2011-02-08 00:00:00
abstract::RecQ helicases are a widely conserved family of ATP-dependent motors with diverse roles in nearly every aspect of bacterial and eukaryotic genome maintenance. However, the physical mechanisms by which RecQ helicases recognize and process specific DNA replication and repair intermediates are largely unknown. Here, we 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.1417594112
更新日期:2015-04-07 00:00:00
abstract::Salt production and trade is thought to be critical to the development of all states and emergent empires. Until now, however, scientific evidence of early salt production has rarely been presented, and no studies of early Chinese salt production have provided unequivocal proof. Here, we report x-ray fluorescence, x-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.0502985102
更新日期:2005-08-30 00:00:00
abstract::Meet Jonathan and Elizabeth. One person is a doctor and the other is a nurse. Who is the doctor? When nothing else is known, the base rate principle favors Jonathan to be the doctor and the fairness principle favors both individuals equally. However, when individuating facts reveal who is actually the doctor, base rat...
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.1524268113
更新日期:2016-07-05 00:00:00
abstract::We describe here the successful establishment of a reverse genetics system for rotavirus (RV), a member of the Reoviridae family whose genome consists of 10-12 segmented dsRNA. The system is based on the recombinant vaccinia virus T7 RNA polymerase-driven procedure for supplying artificial viral mRNA in the cytoplasm....
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.0509385103
更新日期:2006-03-21 00:00:00
abstract::Hepatitis E virus is responsible for both sporadic and epidemic hepatitis in developing countries. The nonenveloped virus is 27-34 nm in diameter and has been shown to contain a single-strand, positive-sense, polyadenylylated RNA genome of approximately 7.5 kilobases. The nucleotide sequence of the Burma strain of hep...
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.89.9.3855
更新日期:1992-05-01 00:00:00
abstract::A panel of rat monoclonal antibodies was used to classify mouse mast cells from four different sources on the basis of their surface determinants. Three populations of mast cells were derived by culturing normal bone marrow, spleen, and peripheral blood cells, whereas the fourth population was isolated directly from 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.80.19.5916
更新日期:1983-10-01 00:00:00
abstract::We have demonstrated that the entire murine N-myc gene and the sequences necessary for its expression in human neuroblastoma cells are contained within a 7.4-kilobase murine genomic clone. The complete nucleotide sequence of this gene reveals a number of striking similarities and differences when compared to the 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.83.6.1827
更新日期:1986-03-01 00:00:00
abstract::Reducible compounds that participate in crosslinking were analyzed in hydroxylysine-deficient collagens of patients with a heritable disorder of connective tissue. After treatment with [(3)H]sodium borohydride, new compounds, as well as a totally different pattern of tritiated compounds, were found in hydroxylysine-de...
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.69.9.2594
更新日期:1972-09-01 00:00:00
abstract::Clathrin-mediated endocytosis (CME) regulates the uptake of cell-surface receptors as well as their downstream signaling activities. We recently reported that signaling can reciprocally regulate CME in cancer cells and that this crosstalk can contribute to cancer progression. To further explore the nature and extent 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.1810209115
更新日期:2018-10-09 00:00:00
abstract::The class II transactivator (CIITA) is the master integrator of expression of MHC class II genes. It interacts with variety of basal transcription factors to initiate and elongate transcription of these genes. Among others, it recruits positive transcription elongation factor b (P-TEFb) to MHC class II promoters. In c...
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.0603079103
更新日期:2006-11-14 00:00:00
abstract::Yawn contagion in humans has been proposed to be related to our capacity for empathy. It is presently unclear whether this capacity is uniquely human or shared with other primates, especially monkeys. Here, we show that in gelada baboons (Theropithecus gelada) yawning is contagious between individuals, especially thos...
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.0910891106
更新日期:2009-11-17 00:00:00
abstract::Infection of HeLa cells with poliovirus results in an inhibition of host-cell protein synthesis. Cytoplasmic extracts from infected cells contian an activity that inhibits initiation of protein synthesis in vitro by rabbit reticulocyte lysates. This inhibitory activity has been purified and characterized, and is shown...
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.68.5.1075
更新日期:1971-05-01 00:00:00
abstract::T cells are essential for immune defenses against pathogens, such that viability of naïve T cells before antigen encounter is critical to preserve a polyclonal repertoire and prevent immunodeficiencies. The viability of naïve T cells before antigen recognition is ensured by IL-7, which drives expression of the prosurv...
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.1315398111
更新日期:2014-05-20 00:00:00
abstract::To monitor inaccuracy in gene expression in living cells, we designed an experimental system in the bacterium Bacillus subtilis whereby spontaneous errors can be visualized and quantified at a single-cell level. Our strategy was to introduce mutations into a chromosomally encoded gfp allele, such that errors in protei...
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.0912989107
更新日期:2010-06-22 00:00:00
abstract::The mechanisms involved in the uptake of uni- and multi-lamellar lipid vesicles by BALB/c mouse 3T3 cells have been investigated. Vesicles are incorporated into cells both by endocytosis and by a nonendocytotic mechanism which we propose involves fusion of vesicles with the plasma membrane. The nonendocytotic pathway ...
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.73.5.1603
更新日期:1976-05-01 00:00:00
abstract::Although(,) vascular remodeling is a hallmark of many chronic inflammatory disorders such as rheumatoid arthritis, inflammatory bowel disease, and psoriasis, anti-vascular strategies to treat these conditions have received little attention to date. We investigated the anti-inflammatory activity of systemic blockade 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.0907550106
更新日期:2009-12-15 00:00:00
abstract::Tetrodotoxin was infused into the suprachiasmatic nuclei of unanesthetized and unrestrained rats continuously for 14 days. The internal timekeeping mechanism of the circadian pacemaker in the nuclei continued to oscillate unaffected by this treatment, although the toxin reversibly blocked function of both the input pa...
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.84.6.1694
更新日期:1987-03-01 00:00:00
abstract::In Salmonella typhimurium, the CobU, CobS, CobT, and CobC proteins have been proposed to catalyze the late steps in adenosylcobalamin biosynthesis, which define the nucleotide loop assembly pathway. This paper reports the in vitro assembly of the nucleotide loop of adenosylcobalamin from its precursors adenosylcobinam...
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.96.21.11798
更新日期:1999-10-12 00:00:00