Abstract:
:Transferrin, a nonheme iron-binding protein, is polymorphic in most vertebrate species that have been examined. In pigeons, it is controlled by an autosomal gene, with two known codominant alleles, Tf(A) and Tf(B). The two alleles are found in nearly equal frequencies and the three genotypes are at Hardy-Weinberg equilibrium in all populations studied. This report shows that ovotransferrins from heterozygous females inhibit microbial growth, by use of yeast as an assay organism, better than ovotransferrins from either of the homozygous types, or those from a mixture of homozygous types. Heterozygous females hatch a larger percentage of their eggs than homozygous females. This difference is probably accounted for by the transferrin effect. The failure of the mixture of the homozygous types to act like the heterozygous type calls into question the currently accepted structure of transferrin as a monomeric protein. The greater fecundity of heterozygous females can account for the maintenance of transferrin polymorphism in pigeons.
journal_name
Proc Natl Acad Sci U S Aauthors
Frelinger JAdoi
10.1073/pnas.69.2.326subject
Has Abstractpub_date
1972-02-01 00:00:00pages
326-9issue
2eissn
0027-8424issn
1091-6490journal_volume
69pub_type
杂志文章abstract::This paper describes a variety of statistical methods for obtaining precise quantitative estimates of the similarities and differences in the structures of semantic domains in different languages. The methods include comparing mean correlations within and between groups, principal components analysis of interspeaker 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.97.1.518
更新日期:2000-01-04 00:00:00
abstract::We have investigated the interaction of human cytomegalovirus (CMV) with cultured primary granulocyte-macrophage progenitors, a suspected natural site of viral latency, and have established conditions for latent infection and reactivation in this cell population. Progenitor cells from human fetal liver or bone marrow ...
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.91.25.11879
更新日期:1994-12-06 00:00:00
abstract::Cyclooxygenase-2 (COX-2) expression is induced by mitogenic and proinflammatory factors. Its overexpression plays a causal role in inflammation and tumorigenesis. COX-2 expression is tightly regulated, but the mechanisms are largely unclear. Here we show the control of COX-2 expression by an endogenous tryptophan meta...
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.1209919109
更新日期:2012-08-14 00:00:00
abstract::Cellular communities in living tissues act in concert to establish intricate microenvironments, with complexity difficult to recapitulate in vitro. We report a method for docking numerous cellularized hydrogel shapes (100-1,000 µm in size) into hydrogel templates to construct 3D cellular microenvironments. Each shape ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 临床试验,杂志文章
doi:10.1073/pnas.1300569110
更新日期:2013-03-19 00:00:00
abstract::For many agronomically important plant genes, only their position on a genetic map is known. In the absence of an efficient transposon tagging system, such genes have to be isolated by map-based cloning. In bread wheat Triticum aestivum, the genome is hexaploid, has a size of 1.6 x 10(10) bp, and contains more than 80...
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.230361597
更新日期:2000-11-21 00:00:00
abstract::The phagocyte NADPH oxidase, dormant in resting cells, is activated during phagocytosis to produce superoxide, a precursor of microbicidal oxidants. The activated oxidase is a complex of membrane-integrated cytochrome b558, composed of 91-kDa (gp91phox) and 22-kDa (p22phox) subunits, and two cytosolic factors (p47phox...
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.91.12.5345
更新日期:1994-06-07 00:00:00
abstract::An earthquake of magnitude M and linear source dimension L(M) is preceded within a few years by certain patterns of seismicity in the magnitude range down to about (M - 3) in an area of linear dimension about 5L-10L. Prediction algorithms based on such patterns may allow one to predict approximately 80% of strong eart...
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.93.9.3748
更新日期:1996-04-30 00:00:00
abstract::An expression is produced for the Casimir energy of a dielectric medium with a spherically symmetrical dielectric discontinuity. Tests based on dielectric and geometrical limits are successful. ...
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.89.23.11118
更新日期:1992-12-01 00:00:00
abstract::In this study we sought to better understand the role of the glycoprotein quality control machinery in the assembly of MHC class I molecules with high-affinity peptides. The lectin-like chaperone calreticulin (CRT) and the thiol oxidoreductase ERp57 participate in the final step of this process as part of the peptide-...
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.1102524108
更新日期:2011-03-22 00:00:00
abstract::In flowering plants, the asymmetrical division of the zygote is the first hallmark of apical-basal polarity of the embryo and is controlled by a MAP kinase pathway that includes the MAPKKK YODA (YDA). In Arabidopsis, YDA is activated by the membrane-associated pseudokinase SHORT SUSPENSOR (SSP) through an unusual pare...
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.1815866116
更新日期:2019-03-19 00:00:00
abstract::Bacteriophage Mu replicates as a transposable element, exploiting host enzymes to promote initiation of DNA synthesis. The phage-encoded transposase MuA, assembled into an oligomeric transpososome, promotes transfer of Mu ends to target DNA, creating a fork at each end, and then remains tightly bound to both forks. In...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.111007898
更新日期:2001-07-17 00:00:00
abstract::The nonlinearity of the Navier-Stokes equations makes predicting the flow of fluid around rapidly moving small bodies highly resistant to all approaches save careful experiments or brute force computation. Here, we show how a linearization of the Navier-Stokes equations captures the drag-determining features of the fl...
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.0810578106
更新日期:2009-03-03 00:00:00
abstract::There is considerable interest in engineering plant cell wall components, particularly lignin, to improve forage quality and biomass properties for processing to fuels and bioproducts. However, modifying lignin content and/or composition in transgenic plants through down-regulation of lignin biosynthetic enzymes can 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.1914422117
更新日期:2020-02-11 00:00:00
abstract::Recent studies have shown that the genes of the gibberellin (GA) biosynthesis pathway in the fungus Gibberella fujikuroi are organized in a cluster of at least seven genes. P450-1 is one of four cytochrome P450 monooxygenase genes in this cluster. Disruption of the P450-1 gene in the GA-producing wild-type strain IMI ...
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.091096298
更新日期:2001-05-08 00:00:00
abstract::A computer code to investigate the equilibrium and stability of a diffuse plasma in three dimensions is described that generalizes earlier work on a sharp free boundary model. Toroidal equilibria of a plasma are determined by considering paths of steepest descent associated with a new version of the variational princi...
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.73.4.984
更新日期:1976-04-01 00:00:00
abstract::The epithelial-derived cytokine thymic stromal lymphopoietin (TSLP) is important for the initiation of allergic airway inflammation through a dendritic cell-mediated T helper 2 response. To identify the factors that control TSLP expression, we examined the ability of inflammatory mediators to regulate TSLP production ...
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.0607305104
更新日期:2007-01-16 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
abstract::Four overlapping cosmid clones were constructed that contain the complete genome of the attenuated Oka strain of VZV. Transfection of human melanoma cells with the four cosmids resulted in production of infectious VZV. A double-stranded oligonucleotide, encoding a stop codon in all three open reading frames, was inser...
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.90.15.7376
更新日期:1993-08-01 00:00:00
abstract::Staphylococcus aureus is a leading cause of both nosocomial and community-acquired infection. Biofilm formation at the site of infection reduces antimicrobial susceptibility and can lead to chronic infection. During biofilm formation, a subset of cells liberate cytoplasmic proteins and DNA, which are repurposed to for...
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.1704544114
更新日期:2017-07-18 00:00:00
abstract::General control nonderepressible 2 (GCN2) plays a major role in the cellular response to amino acid limitation. Although maintenance of amino acid homeostasis is critical for tumor growth, the contribution of GCN2 to cancer cell survival and proliferation is poorly understood. In this study, we generated GCN2 inhibito...
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.1805523115
更新日期:2018-08-14 00:00:00
abstract::Photochemical release (uncaging) of bioactive messengers with three-dimensional spatial resolution in light-scattering media would be greatly facilitated if the photolysis could be powered by pairs of IR photons rather than the customary single UV photons. The quadratic dependence on light intensity would confine 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.96.4.1193
更新日期:1999-02-16 00:00:00
abstract::The INT6 gene has been implicated in human breast cancer formation, but its function is unknown. We isolated an Int6 homolog from fission yeast, Yin6, by its binding to a conserved protein in the Ras pathway, Moe1. Yin6 and Moe1 converge on the same protein complex to promote microtubule instability/disassembly. Yin6 ...
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.97.26.14370
更新日期:2000-12-19 00:00:00
abstract::Tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1) by the insulin receptor permits this docking protein to interact with signaling proteins that promote insulin action. Serine phosphorylation uncouples IRS-1 from the insulin receptor, thereby inhibiting its tyrosine phosphorylation and insulin signaling....
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.051042298
更新日期:2001-04-10 00:00:00
abstract::The post-translational proteolytic conversion of somatostatin-14 precursors was studied to characterize the enzyme system responsible for the production of the tetradecapeptide either from its 15-kDa precursor protein or from its COOH-terminal fragment, somatostatin-28. A synthetic undecapeptide Pro-Arg-Glu-Arg-Lys-Al...
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.81.21.6662
更新日期:1984-11-01 00:00:00
abstract::Estrogen receptor alpha (ERalpha) plays a major role in the regulation of neuroendocrine functions and behaviors by estrogens. Although the generation of ERalpha knockout mice advanced our knowledge of ERalpha functions, gene deletion using this method is global and potentially confounded by developmental consequences...
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.0603045103
更新日期:2006-07-05 00:00:00
abstract::New approaches to the study of early hominin diets have refreshed interest in how and when our diets diverged from those of other African apes. A trend toward significant consumption of C4 foods in hominins after this divergence has emerged as a landmark event in human evolution, with direct evidence provided by stabl...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.2006221117
更新日期:2020-09-08 00:00:00
abstract::The eukaryotic small ribosomal subunit carries only four ribosomal (r) RNA methylated bases, all close to important functional sites. N(7)-methylguanosine (m(7)G) introduced at position 1575 on 18S rRNA by Bud23-Trm112 is at a ridge forming a steric block between P- and E-site tRNAs. Here we report atomic resolution 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.1413089111
更新日期:2014-12-23 00:00:00
abstract::The traditional morphologically grounded placement of South American guinea pig-like rodents (Caviomorpha) within one of the two rodent suborders, Hystricognathi, has been disputed by recent analysis of protein and nucleic acid sequence data. The Caviomorpha and possibly all Hystricognathi would be considered a separa...
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.90.20.9698
更新日期:1993-10-15 00:00:00
abstract::The accurate biogenesis of RNA-protein complexes is a key aspect of eukaryotic cells. Defects in Sm protein complex binding to snRNAs are known to reduce levels of snRNAs, suggesting an unknown quality control system for small nuclear ribonucleoprotein (snRNP) assembly. snRNA quality control may also be relevant in sp...
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.1412614111
更新日期:2014-08-12 00:00:00
abstract::A fraction of the unintegrated viral DNA that appears early after infection of mouse cells by Moloney leukemia virus is infectious. The infectivity could be deomonstrated by an XC plaque assay of the cells exposed to DNA co-precipitated with calcium phosphate. The number of plaques deriving from closed-circular, super...
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.72.12.4910
更新日期:1975-12-01 00:00:00