Abstract:
:A recently described experimental system for analyzing the mode of action of a morphogen gradient involves the in situ hybridization of sectioned tissue constructs. In these constructs, a source of activin signaling induces the transcription of several mesodermal genes in blastula animal caps, according to the position of cells in a concentration gradient. New experiments show that activin-loaded beads emit a signal for only 2 hr and that the same cell can be induced to express different genes. We determine the position in the gradient and the time after the start of activin signaling at which early genes, including Mix1, Xpo, Xwnt8, Xchd, and Xlim1, are activated, relative to the previously tested genes Xbra and Xgsc.
journal_name
Proc Natl Acad Sci U S Aauthors
Gurdon JB,Mitchell A,Ryan Kdoi
10.1073/pnas.93.18.9334subject
Has Abstractpub_date
1996-09-03 00:00:00pages
9334-8issue
18eissn
0027-8424issn
1091-6490journal_volume
93pub_type
杂志文章,评审abstract::Losses are a possibility in many risky decisions, and organisms have evolved mechanisms to evaluate and avoid them. Laboratory and field evidence suggests that people often avoid risks with losses even when they might earn a substantially larger gain, a behavioral preference termed "loss aversion." The cautionary brak...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.0910230107
更新日期:2010-02-23 00:00:00
abstract::It has been shown that [35S]methionine is incorporated into the [Met]enkephalin sequences of a 22,000-dalton enkephalin-containing protein in the adrenal medulla. Pulse-chase experiments indicate that label is incorporated into the large polypeptide before it appears in free [Met]enkephalin and a smaller [Met]enkephal...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.77.11.6889
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abstract::The influenza virus hemagglutinin polypeptides, HA1 and HA2, have been purified by gel filtration in the presence of sodium dodecyl sulfate from a vaccine preparation of the recombinant strain Heq1N2. Use of this technique for purification of the hemagglutinin polypeptides eliminated the need for proteolytic agents fo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.73.1.238
更新日期:1976-01-01 00:00:00
abstract::To understand complex biological systems, such as the development of multicellular organisms, it is important to characterize the gene expression dynamics. However, there is currently no universal technique for targeted insertion of reporter genes and quantitative imaging in multicellular model systems. Recently, geno...
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.1202768109
更新日期:2012-07-03 00:00:00
abstract::NFATc (a member of the family of nuclear factors of activated T cells) is a transcriptional factor responsible for the Ca(2+)-inducible activation of cytokine genes during the immune response. In resting T cells, NFATc is retained in the cytoplasm by a mechanism that depends on multiple phosphorylations in an N-termin...
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.97.13.7130
更新日期:2000-06-20 00:00:00
abstract::To modify the lac permease of Escherichia coli for fluorescence spectroscopy, six tryptophan residues at positions 10, 33, 78, 151, 171, and 223 were first replaced individually with phenylalanine by using oligonucleotide-directed site-specific mutagenesis. None of the tryptophan residues is critical for activity, as ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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abstract::Interspersed repeated sequences (Alu and Kpn) were used as probes to detect a set of Not I restriction fragments of human chromosome 21 from the hybrid cell line WAV17. Forty different Not I fragments, ranging in size from less than 0.05 megabase (Mb) to 7.0 Mb, were identified. The total length of these fragments was...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1992-02-01 00:00:00
abstract::Metastatic colorectal cancer (mCRC) patients have poor overall survival despite using irinotecan- or oxaliplatin-based chemotherapy combined with anti-EGFR (epidermal growth factor receptor) drugs, especially those with the oncogene mutation of KRAS Metformin has been reported as a potentially novel antitumor agent in...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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abstract::Ca(2+) is known to have important roles in sperm chemotaxis, although the relationship between intracellular Ca(2+) concentration ([Ca(2+)](i)) and modulation of the swimming and chemotactic behavior of spermatozoa has not been elucidated. Using a high-speed Ca(2+) imaging system, we examined the chemotactic behavior ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2008-12-09 00:00:00
abstract::In translation, elongation factor Tu (EF-Tu) molecules deliver aminoacyl-tRNAs to the mRNA-programmed ribosome. The GTPase activity of EF-Tu is triggered by ribosome-induced conformational changes of the factor that play a pivotal role in the selection of the cognate aminoacyl-tRNAs. We present a 6.7-A cryo-electron m...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2009-01-27 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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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.0806977105
更新日期:2008-11-11 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
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更新日期:1993-06-01 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.94.19.10330
更新日期:1997-09-16 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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abstract::The basis for the 200-fold difference in affinity between two hybridoma antibodies specific for the hapten p-azophenylarsonate (Ars) that have diversified by somatic hypermutation was examined. Oligonucleotide-directed mutagenesis was used to sequentially convert the nucleotide sequence of the lower-affinity antibody ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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abstract::Physical and gene mapping studies reveal that chloroplast DNA from geranium (Pelargonium hortorum) has sustained a number of extensive duplications and inversions, resulting in a genome arrangement radically unlike that of other plants. At 217 kilobases in size, the circular chromosome is about 50% larger than the typ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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abstract::Pathogenic retroviruses have evolved multiple means for evading host restriction factors such as apolipoprotein B editing complex (APOBEC3) proteins. Here, we show that murine leukemia virus (MLV) has a unique means of counteracting APOBEC3 and other cytosolic sensors of viral nucleic acid. Using virus isolated from i...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2013-05-28 00:00:00
abstract::The transformation of new experiences into lasting memories is thought to be mediated by postencoding reactivation or the reexpression of activity patterns that characterize prior encoding experiences during subsequent offline periods. Although hippocampal reactivation has been well-described in the rodent, evidence f...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2013-11-26 00:00:00
abstract::The chromosomal locations of cellular sequences flanking integrated papillomavirus DNA in four cervical carcinoma cell lines and a primary cervical carcinoma have been determined. The two human papillomavirus (HPV) 16 flanking sequences derived from the tumor were localized to chromosome regions 20pter----20q13 and 3p...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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abstract::Neural circuits are generated by precisely ordered synaptic connections among neurons, and this process is thought to rely on the ability of neurons to recognize specific partners. However, it is also known that neurons promiscuously form synapses with nonspecific partners, in particular when cultured in vitro, causin...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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abstract::The association between poor paternal diet, perturbed embryonic development, and adult offspring ill health represents a new focus for the Developmental Origins of Health and Disease hypothesis. However, our understanding of the underlying mechanisms remains ill-defined. We have developed a mouse paternal low-protein ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2018-10-02 00:00:00
abstract::This study was undertaken to characterize bile acid metabolism in hereditary forms of hypertriglyceridemia. Ten hypertriglyceridemic patients (type IV phenotype) with familial combined hyperlipidemia and 7 patients with monogenic familial hypertriglyceridemia (FHTG) were compared with 18 healthy controls; all subjects...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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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
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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::Recent political instabilities and conflicts around the world have drastically increased the number of people seeking refuge. The challenges associated with the large number of arriving refugees have revealed a deep divide among the citizens of host countries: one group welcomes refugees, whereas another rejects them....
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2018-07-10 00:00:00
abstract::The synthesis of a photosensitive blocking group for the carboxyl function of neurotransmitters, in this case glycine, is reported. The compound, 2-methoxy-5-nitrophenyl glycine ester (caged glycine), is photolyzed by a laser pulse at 308 or 337 nm within 3 microseconds and with a product quantum yield of 0.2. The com...
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.90.23.11074
更新日期:1993-12-01 00:00:00