Abstract:
:The preferential inactivation of the paternal X chromosome in extraembryonic cells during early mouse development is an example of parental imprinting, but it has not been studied at the transcriptional level because standard methods of measuring RNA levels do not allow detection of allele-specific RNAs in individual early embryos. We sought to determine whether the paternal allele of the X chromosome-linked gene for 3-phosphoglycerate kinase 1 (Pgk-1), which is located very near the center of X chromosome inactivation, is transcribed prior to differentiation of extraembryonic lineages. Previous reports indicated that in heterozygous embryos there is a delay in the appearance of the phosphoglycerate kinase 1 allozyme encoded by the paternal X chromosome until 2 days after the appearance of the corresponding maternal allozyme. We report results obtained by use of a reverse transcription/PCR-based method which allows the quantitative measurement of allele-specific RNA. The assay is sensitive enough for the quantitative analysis in single embryos of allele-specific transcripts differing by only one nucleotide. We have used this assay to analyze mouse embryos heterozygous at the Pgk-1 and Hprt [hypoxanthine (guanine) phosphoribosyltransferase] loci, and we find that individual 8-cell and blastocyst embryos express both Hprt and Pgk-1 paternal transcripts, as do pooled 2- to 4-cell embryos. These results are discussed in view of the apparent temporal delay in paternal expression of the Pgk-1 gene at the enzyme level.
journal_name
Proc Natl Acad Sci U S Aauthors
Singer-Sam J,Chapman V,LeBon JM,Riggs ADdoi
10.1073/pnas.89.21.10469keywords:
subject
Has Abstractpub_date
1992-11-01 00:00:00pages
10469-73issue
21eissn
0027-8424issn
1091-6490journal_volume
89pub_type
杂志文章abstract::Broken-cell preparations of Salmonella typhimurium rapidly incorporated 75Se from 75SeO3(2-) into tRNA by an ATP-dependent process. Selenium incorporation in the presence of 50 microM 75SeO3(2-) (0.8-1 pmol per A260 unit) was enhanced by the selenocysteine precursor, O-acetyl-L-serine (to 3.7 pmol per A260 unit). This...
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.87.16.6341
更新日期:1990-08-01 00:00:00
abstract::RNA was synthesized in vitro from a T3 DNA template by T3 RNA polymerase and subsequently separated into seven discrete size classes (molecular weights ranging between 0.21 x 10(6) and 6.2 x 10(6)) by electrophoresis in polyacrylamide slab gels. RNase T1-generated 3'-terminal oligonucleotide fragments were then select...
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.76.10.5110
更新日期:1979-10-01 00:00:00
abstract::The dynamics of social networks can determine the transmission of information, the spread of diseases, and the evolution of behavior. Despite this broad importance, a general framework for predicting social network stability has not been proposed. Here we present longitudinal data on the social dynamics of a cooperati...
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.1913284117
更新日期:2020-02-11 00:00:00
abstract::Macropinocytosis is a highly conserved endocytic process by which extracellular fluid and solutes are internalized into cells. Macropinocytosis starts with the formation of membrane ruffles at the plasma membrane and ends with their closure. The transient and sequential emergence of phosphoinositides PI(3,4,5)P3 and P...
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.1311029111
更新日期:2014-03-18 00:00:00
abstract::A single anterior-animal blastomere, which includes the presumptive neural region in the eight-cell embryo of the Halocynthia, a protochordate, when dissociated, cleavage-arrested with cytochalasin B, and cultured in isolation, differentiated exclusively to epidermal type judging from membrane excitability and immunor...
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.85.16.6197
更新日期:1988-08-01 00:00:00
abstract::The interactions between products of the 15-lipoxygenase cascade and human natural killer (NK) cell activity have been studied. Addition of human leukocyte-derived (14R,15S)-14,15-dihydroxy-5Z,8Z,10E,12E-ic osatetraenoic acid (14,15-DiHETE) to the NK cytotoxicity assay against K562 target cells resulted in inhibition ...
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.81.22.6914
更新日期:1984-11-01 00:00:00
abstract::FAP48 was identified and cloned thanks to its interaction with FK506-binding proteins (FKBPs) such as FKBP52 and FKBP12, which belong to the large family of immunophilins that bind the macrolide immunosuppressant drugs FK506 and rapamycin. We have previously shown that FAP48-FKBP complexes are dissociated by FK506 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.0438007100
更新日期:2003-03-04 00:00:00
abstract::In adult rat testes, the blood-testis barrier (BTB) in the seminiferous epithelium must "open" (or "disassemble") to accommodate the migration of preleptotene spermatocytes from the basal to the adluminal compartment that occurs at stage VIII of the epithelial cycle. However, the molecule(s) and/or mechanism(s) that 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.0610100104
更新日期:2007-03-06 00:00:00
abstract::Mass-independent isotope fractionations driven by differences in volumes and shapes of nuclei (the field shift effect) are known in several elements and are likely to be found in more. All-electron relativistic electronic structure calculations can predict this effect but at present are computationally intensive and 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.1216216110
更新日期:2013-10-29 00:00:00
abstract::Photoperiodic control of testis growth in Passer domesticus (house sparrow) is mediated entirely by extraretinal photoreceptors in the brain. The eyes do not participate in photoperiodically significant photoreception. Removal of the pineal organ does not affect either the response to light or, to a first approximatio...
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.67.1.320
更新日期:1970-09-01 00:00:00
abstract::Cryptochromes are blue-light receptors mediating various light responses in plants and animals. The photochemical mechanism of cryptochromes is not well understood. It has been proposed that photoactivation of cryptochromes involves the blue-light-dependent photoreduction of flavin adenine dinucleotide via the electro...
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.1114579108
更新日期:2011-12-20 00:00:00
abstract::Mitochondrial cytochrome c oxidase plays an essential role in aerobic cellular respiration, reducing dioxygen to water in a process coupled with the pumping of protons across the mitochondrial inner membrane. An aspartate residue, Asp-51, located near the enzyme surface, undergoes a redox-coupled x-ray structural chan...
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.2635097100
更新日期:2003-12-23 00:00:00
abstract::G protein-gated inwardly rectifying potassium (GIRK) channels are critical regulators of neuronal excitability and can be directly activated by ethanol. Constitutive deletion of the GIRK3 subunit has minimal phenotypic consequences, except in response to drugs of abuse. Here we investigated how the GIRK3 subunit contr...
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.1416146112
更新日期:2015-06-02 00:00:00
abstract::The notion that tRNA and 5S rRNA interact through evolutionarily conserved complementary sequences has been tested by nucleolytic modification of the 5S rRNA, using the modified rRNA to reconstitute the large ribosomal subunit, and assaying for poly(uridylic acid)-directed polyphenylalanine synthesis. The 5S rRNA sequ...
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.79.1.36
更新日期:1982-01-01 00:00:00
abstract::Understanding the gene-expression patterns during liver regeneration may help to reveal how regenerative processes are initiated and controlled as well as shed new light onto processes that lead to liver disease. Using high-density oligonucleotide arrays, we have examined the gene-expression program in the livers of 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.122359899
更新日期:2002-08-20 00:00:00
abstract::In many eukaryotic systems during immune responses, mitogen-activated protein kinases (MAPKs) link cytoplasmic signaling to chromatin events by targeting transcription factors, chromatin remodeling complexes, and the RNA polymerase machinery. So far, knowledge on these events is scarce in plants and no attempts have 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.2004670118
更新日期:2021-01-19 00:00:00
abstract::In a previous paper we described the induction by x-irradiation or radiation-induced leukemia virus-inoculation of two classes of lymphoid T-cell neoplasms: The first class, designated T-cell lymphoblastoma (TCLB), consists of growth-factor-dependent eudiploid cells that home to the spleen and give rise to splenic tum...
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.81.6.1742
更新日期:1984-03-01 00:00:00
abstract::Dark-cycle, night administration of the pineal hormone melatonin in drinking water to aging mice (15 months of age) prolongs survival of BALB/c females from 23.8 to 28.1 months and preserves aspects of their youthful state. Similar results were seen in New Zealand Black females beginning at 5 months and C57BL/6 males ...
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.91.2.787
更新日期:1994-01-18 00:00:00
abstract::Zif268, a zinc finger protein whose mRNA is rapidly activated in cells exposed to growth factors or other signaling agents, is thought to play a role in regulating the genetic program induced by extracellular ligands. We report that Zif268 has one of the characteristics of a transcriptional regulator, namely, sequence...
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.86.22.8737
更新日期:1989-11-01 00:00:00
abstract::Exposing primary cultures of cerebellar granule neurons to 100 nM phorbol 12-myristate 13-acetate (PMA) for 24 hr decreases the Ca2+/phosphatidylserine/diolein-dependent protein kinase C (PKC; ATP:protein phosphotransferase, EC 2.7.1.37) by approximately 90% in the 100,000 x g supernatant and pellet fractions of neuro...
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.87.5.1983
更新日期:1990-03-01 00:00:00
abstract::DNA heteroduplexes with single unpaired bases of the four different kinds were prepared by annealing separated strands of bacteriophage lambda DNA and used to transfect Escherichia coli. Genetic analysis of the progeny phages obtained from transfected bacteria indicates that the E. coli mismatch repair system can reco...
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.83.10.3395
更新日期:1986-05-01 00:00:00
abstract::One of the earliest detectable events during plant-pathogen interaction is a rapid increase in ethylene biosynthesis. This gaseous plant stress hormone may be a signal for plants to activate defense mechanisms against invading pathogens such as bacteria, fungi, and viruses. The effect of ethylene on four plant genes i...
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.84.15.5202
更新日期:1987-08-01 00:00:00
abstract::Human languages show a remarkable degree of variation in the area they cover. However, the factors governing the distribution of human cultural groups such as languages are not well understood. While previous studies have examined the role of a number of environmental variables the importance of cultural factors has n...
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.0804698106
更新日期:2009-05-05 00:00:00
abstract::Hereditary deficiency of factor IXa (fIXa), a key enzyme in blood coagulation, causes hemophilia B, a severe X chromosome-linked bleeding disorder afflicting 1 in 30,000 males; clinical studies have identified nearly 500 deleterious variants. The x-ray structure of porcine fIXa described here shows the atomic origins ...
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.92.21.9796
更新日期:1995-10-10 00:00:00
abstract::Hydrocortisone at physiological concentrations reversibly inhibits DNA synthesis in ST1 cells (a line of mouse fibroblasts possessing 40 chromosomes and derived from Swiss 3T3 cells). This inhibitory activity is a property of glucocorticoids, but the beta-OH of C-11 of glucocorticoids is not essential for the inhibiti...
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.75.6.2805
更新日期:1978-06-01 00:00:00
abstract::In this article, we address the problem of modeling generic features of structurally but not textually related DNA motifs, that is, motifs whose consensus sequences are entirely different but nevertheless share "metasequence features" reflecting similarities in the DNA-binding domains of their associated protein recog...
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.0403564101
更新日期:2004-07-20 00:00:00
abstract::Branched polyethylenimine (PEI) chains with an average molecular mass of 2 kDa (PEI2) have been covalently attached to gold nanoparticles (GNPs), and the potency of the resulting PEI2-GNPs conjugates as vectors for the delivery of plasmid DNA into monkey kidney (COS-7) cells in the presence of serum in vitro has been ...
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.1233634100
更新日期:2003-08-05 00:00:00
abstract::Which network structures favor the rapid spread of new ideas, behaviors, or technologies? This question has been studied extensively using epidemic models. Here we consider a complementary point of view and consider scenarios where the individuals' behavior is the result of a strategic choice among competing alternati...
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.1004098107
更新日期:2010-11-23 00:00:00
abstract::When encountering unexpected event changes, memories of relevant past experiences must be updated to form new representations. Current models of memory updating propose that people must first generate memory-based predictions to detect and register that features of the environment have changed, then encode the new eve...
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.1918063117
更新日期:2020-11-24 00:00:00
abstract::Active center fractions have been prepared from Rhodopseudomonas spheroides strain Y. (de Klerk) using the cationic detergent cetyltrimethyl ammonium bromide and light particles from bacteria grown in two media differing in iron content. Spectral properties and composition of the fractions are presented. ...
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.64.2.650
更新日期:1969-10-01 00:00:00