Abstract:
:Restriction site variation in DNA that encodes rRNA (rDNA) was surveyed among 714 offspring within 31 lineages (26 genotypes) of obligate asexually reproducing Taraxacum officinale (dandelions). Although clonal offspring are expected, plants with nonparental rDNA were produced from two parents that were themselves siblings (same genotype). The variation is best characterized by the loss of an EcoRI restriction site that maps to the spacer region in the parental rDNA and is most likely involved in amplification of rare or unique rDNA repeats. In one family, 41 surveyed offspring lacked the EcoRI site. In the other family, only 1 of 26 offspring lost the EcoRI site. Other classes of DNA surveyed, chloroplast DNA and the alcohol dehydrogenase 2 gene (Adh2), showed no variation. However, offspring with nonparental rDNA also had nonparental alcohol dehydrogenase 1 (Adh1) restriction fragments. Because somatic mutations in plants can be incorporated into reproductive tissue, we propose that somatic events affecting at least both multicopy rDNA and DNA homologous to the maize Adh1 gene occurred at different developmental times in the two families. An event early in development would result in all variant offspring; an event late in development would result in a single variant offspring. These results support the view that mutation (in the broad sense) influences the level of genotypic variation in asexual organisms, which may facilitate adaptive evolution of asexual species.
journal_name
Proc Natl Acad Sci U S Aauthors
King LM,Schaal BAdoi
10.1073/pnas.87.3.998subject
Has Abstractpub_date
1990-02-01 00:00:00pages
998-1002issue
3eissn
0027-8424issn
1091-6490journal_volume
87pub_type
杂志文章abstract::Recent excavations at Pre-Pottery Neolithic A (PPNA) WF16 in southern Jordan have revealed remarkable evidence of architectural developments in the early Neolithic. This sheds light on both special purpose structures and "domestic" settlement, allowing fresh insights into the development of increasingly sedentary comm...
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.1017642108
更新日期:2011-05-17 00:00:00
abstract::Autophagy, a conserved pathway that delivers intracellular materials into lysosomes for degradation, is involved in development, aging, and a variety of diseases. Accumulating evidence demonstrates that autophagy plays a protective role against infectious diseases by diminishing intracellular pathogens, including bact...
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.1405032111
更新日期:2014-08-26 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::Full-length 66-kDa estrogen receptor alpha (ERalpha) stimulates target gene transcription through two activation functions (AFs), AF-1 in the N-terminal domain and AF-2 in the ligand binding domain. Another physiologically expressed 46-kDa ERalpha isoform lacks the N-terminal A/B domains and is consequently devoid 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.0808742106
更新日期:2009-02-10 00:00:00
abstract::Expression of glucokinase in hepatocytes and pancreatic 6-cells is of major physiologic importance to mammalian glucose homeostasis. Liver glucokinase catalyzes the first committed step in the disposal of glucose, and beta-cell glucokinase catalyzes a rate-limiting step required for glucose-regulated insulin release. ...
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.93.14.7036
更新日期:1996-07-09 00:00:00
abstract::Hearing is one of the last sensory modalities to be subjected to genetic analysis in Drosophila melanogaster. We describe a behavioral assay for auditory function involving courtship among groups of males triggered by the pulse component of the courtship song. In a mutagenesis screen for mutations that disrupt the aud...
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.94.26.14837
更新日期:1997-12-23 00:00:00
abstract::CD4 can physically associate with the CD3-T-cell receptor complex as visualized in cocapping experiments. This association occurs when the T-cell receptor is cross-linked by certain anti-variable region antibodies that appear to induce a conformational change in the receptor such that it associate with CD4. Similar as...
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.86.9.3311
更新日期:1989-05-01 00:00:00
abstract::Pathogenic infections and tissue injuries trigger the assembly of inflammasomes, cytosolic protein complexes that activate caspase-1, leading to cleavage of pro-IL-1β and pro-IL-18 and to pyroptosis, a proinflammatory cell death program. Although microbial recognition by Toll-like receptors (TLRs) is known to induce 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.1320294111
更新日期:2014-01-14 00:00:00
abstract::The Lyz endolysin of bacteriophage P1 was found to cause lysis of the host without a holin. Induction of a plasmid-cloned lyz resulted in lysis, and the lytic event could be triggered prematurely by treatments that dissipate the proton-motive force. Instead of requiring a holin, export was mediated by an N-terminal tr...
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.0400957101
更新日期:2004-04-27 00:00:00
abstract::We have developed three computer programs for comparisons of protein and DNA sequences. They can be used to search sequence data bases, evaluate similarity scores, and identify periodic structures based on local sequence similarity. The FASTA program is a more sensitive derivative of the FASTP program, which can be us...
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.85.8.2444
更新日期:1988-04-01 00:00:00
abstract::There exist a limited but growing number of biological metal centers whose properties lie conspicuously outside the realm of known inorganic chemistry. The synthetic analogue approach, broadly directed, offers a powerful exploratory tool that can define intrinsic chemical possibilities for these sites while simultaneo...
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.0630028100
更新日期:2003-04-01 00:00:00
abstract::As the most prototypical G protein-coupled receptor, beta-adrenergic receptor (betaAR) regulates the pace and strength of heart beating by enhancing and synchronizing L-type channel (LCC) Ca(2+) influx, which in turn elicits greater sarcoplasmic reticulum (SR) Ca(2+) release flux via ryanodine receptors (RyRs). Howeve...
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.0906560106
更新日期:2009-10-20 00:00:00
abstract::Coastal hypoxia (dissolved oxygen ≤ 2 mg/L) is a growing problem worldwide that threatens marine ecosystem services, but little is known about economic effects on fisheries. Here, we provide evidence that hypoxia causes economic impacts on a major fishery. Ecological studies of hypoxia and marine fauna suggest multipl...
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.1617948114
更新日期:2017-02-14 00:00:00
abstract::I describe the self-splicing of an RNA that consists of exon sequences flanked by group II intron sequences. I find that this RNA undergoes accurate splicing in vitro, yielding an excised exon circle. This splicing reaction involves the joining of the 5' splice site at the end of an exon to the 3' splice site at the 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.90.18.8624
更新日期:1993-09-15 00:00:00
abstract::To test directly whether fibrin(ogen) is a key binding site for apolipoprotein(a) [apo(a)] in vessel walls, apo(a) transgenic mice and fibrinogen knockout mice were crossed to generate fibrin(ogen)-deficient apo(a) transgenic mice and control mice. In the vessel wall of apo(a) transgenic mice, fibrin(ogen) deposition ...
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.95.21.12591
更新日期:1998-10-13 00:00:00
abstract::Micron-scale robots require systems that can morph into arbitrary target configurations controlled by external agents such as heat, light, electricity, and chemical environment. Achieving this behavior using conventional approaches is challenging because the available materials at these scales are not programmable lik...
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.1922635117
更新日期:2020-04-21 00:00:00
abstract::Inactivation of the p53 pathway represents the most common molecular defect of human cancer. But in the setting of melanoma, a highly aggressive and invariably fatal malignancy in its advanced disseminated form, mutation/deletion of p53 is relatively rare, whereas its positive regulator ARF is often lost. Here, we sho...
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.0611638104
更新日期:2007-06-26 00:00:00
abstract::We have determined the nucleotide sequences of the Klebsiella pneumoniae nifL (regulation of N2 fixation genes) and the Escherichia coli glnA (glutamine synthetase) promoters. We compared these sequences with the published sequences of three other promoters that, like the nifL and glnA promoters, are activated by 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.80.9.2524
更新日期:1983-05-01 00:00:00
abstract::The extracellular hemoglobin of Ascaris has an extremely high oxygen affinity (P50 = 0.004 mmHg). It consists of eight identical subunits of molecular weight 40,600. Their sequence, determined by protein chemistry, shows two tandemly linked globin-like sequences and an 18-residue C-terminal extension. Two N-linked gly...
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.89.10.4638
更新日期:1992-05-15 00:00:00
abstract::Inositol 1,4,5-trisphosphate (IP(3)) receptors (IP(3)Rs) are IP(3)-gated Ca(2+) channels that are located on intracellular Ca(2+) stores. We previously identified an IP(3)R binding protein, termed IP(3)R binding protein released with IP(3) (IRBIT). Because IRBIT is released from IP(3)R by physiological concentrations ...
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.0602250103
更新日期:2006-06-20 00:00:00
abstract::The serotonin transporter (SERT) is a major regulator of serotonergic neurotransmission and anxiety-related behaviors. SERT is expressed in two alternative polyadenylation forms that differ by an evolutionarily conserved element in the 3' untranslated region of its mRNA. Expression of SERT mRNA containing the distal 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.1301485110
更新日期:2013-07-09 00:00:00
abstract::Invariant natural killer T (iNKT) cells recognize self lipid antigens presented by CD1d molecules. The nature of the self-antigens involved in the development and maturation of iNKT cells is poorly defined. Lysophospholipids are self-antigens presented by CD1d that are generated through the action of phospholipases A1...
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.1302923110
更新日期:2013-03-26 00:00:00
abstract::Incommensurate charge order in hole-doped oxides is intertwined with exotic phenomena such as colossal magnetoresistance, high-temperature superconductivity, and electronic nematicity. Here, we map, at atomic resolution, the nature of incommensurate charge-lattice order in a manganite using scanning transmission elect...
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.1714901115
更新日期:2018-02-13 00:00:00
abstract::Antigen receptors on the T-cell surface are noncovalently associated with at least four invariant polypeptide chains, CD3-gamma, -delta, -epsilon, and -zeta. The mouse CD3-gamma gene, consisting of seven exons, was found to be highly homologous to the CD3-delta gene described earlier. Both the high level of sequence h...
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.84.24.9131
更新日期:1987-12-01 00:00:00
abstract::Although peroxisome proliferator-activated receptor gamma (PPARgamma) agonists such as thiazolidinediones (TZDs) are widely used to treat type 2 diabetes, how its activation in individual tissues contributes to TZD's therapeutic action remains controversial. As TZDs are known to have receptor-independent effects, 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.0912487106
更新日期:2009-12-29 00:00:00
abstract::The time course of thermal reactions after illumination of 100% humidified bacteriorhodopsin films was followed with FTIR spectroscopy between 125 and 195 K. We monitored the conversion of the initial photoproduct, K, to the next, L intermediate, and a shunt reaction of the L state directly back to the initial BR stat...
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.0703859104
更新日期:2007-06-05 00:00:00
abstract::Human Creutzfeldt-Jakob disease (CJD) and similar neurodegenerative diseases such as sheep scrapie are caused by a variety of related infectious agents. They are associated with abnormal host prion protein (PrP), which is assessed by limited proteolysis to yield resistant PrP bands (PrP-res). Although PrP-res 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.0400158101
更新日期:2004-06-08 00:00:00
abstract::A segment of DNA containing cya, the gene for adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1], has been isolated from Salmonella typhimurium. The phage lambda gt4 was used as a cloning vector and adenylate cyclase-positive hybrid phages were isolated that complemented adenylate cyclase-negative bac...
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.78.8.4684
更新日期:1981-08-01 00:00:00
abstract::Synthetic oligonucleotide probes can be easily obtained and used, in contrast to cDNA cloning to develop probes, and thus the present study was carried out to determine whether such probes could also be useful for in situ hybridization. A 24-base synthetic oligonucleotide complementary to part of the alpha-melanocyte-...
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.83.15.5419
更新日期:1986-08-01 00:00:00
abstract::The novel immune-type receptor (NITR) genes encode a unique multigene family of leukocyte regulatory receptors, which possess an extracellular Ig variable (V) domain and may function in innate immunity. Artificial chromosomes that encode zebrafish NITRs have been assembled into a contig spanning approximately 350 kb. ...
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.0405242101
更新日期:2004-11-02 00:00:00