abstract：:Lines containing two third-chromosome inversions (Arrowhead and Pikes Peak) of Drosophila pseudoobscura selected for fast and slow mating speed were crossed to a multichromosomal, dominant marker inversion stock, and strains with various combinations of chromosomal derivation were tested for their mating activity. Whe...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Sherwin RN,Spiess EB

更新日期：1973-02-01 00:00:00

abstract：:A water-soluble component of membranes of cells from a Burkitt's lymphoma cultured cell line was used to develop an antiserum that detects an antigen(s) on acute leukemia cells. This antiserum did not react with nonlymphoid cultured cell lines except for human embryonic kidney cells infected with the Rauscher murine l...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Mann DL,Halterman R,Leventhal BG

更新日期：1973-02-01 00:00:00

abstract：:The oligopeptide permease of Escherichia coli has been characterized by Payne, Gilvarg, and their colleagues. We have confirmed its existence in Salmonella typhimurium, and have isolated a series of mutants lacking the permease. We use this transport system for smuggling a histidine biosynthetic intermediate, histidin...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ames BN,Ames GF,Young JD,Tsuchiya D,Lecocq J

更新日期：1973-02-01 00:00:00

abstract：:An acetone extract of chloroplast particles, when layered on an aqueous surface, exhibited light-dependent phosphorylation. Studies with the firefly-tail enzyme assay, as well as with (32)P-labeled inorganic phosphate, show an initial release of adenosine triphosphate (a step that is apparently only light-triggered), ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： McPhee J,Brody SS

更新日期：1973-01-01 00:00:00

abstract：:During CsCl isopycnic centrifugation at 20 mM Mg(++), Escherichia coli 30S ribosomal subunits specifically lose proteins S1, S2, S3, S5, S9, S10, and S14. The resultant 30S core is unable to stimulate the GTPase activity of EF-G in the presence of 50S subunits. Activity could be restored to a small extent by adding ba...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Marsh RC,Parmeggiani A

更新日期：1973-01-01 00:00:00

abstract：:Lipid-soluble spin labels were incorporated into human lymphocytes and mouse L-cells and the resulting electron spin resonance spectra were compared with spectra obtained from similarly labeled human erythrocytes. Spin labels were found in all subcellular fractions of the nucleated cells that contained membranes. Spin...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kaplan J,Canonico PG,Caspary WJ

更新日期：1973-01-01 00:00:00

abstract：:The rate of leucine incorporation into a specific estrogen-induced protein of immature rat isolated by gel electrophoresis declines rapidly between 2-4 hr after estrogen stimulation in vivo followed by incubation in vitro. Actinomycin D present during the in vitro phase prevents this decline, and elicits a "superinduc...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： DeAngelo AB,Fujimoto GI

更新日期：1973-01-01 00:00:00

abstract：:Squalene and sterol carrier protein of liver plays a general role as a vehicle for cholesterol and its water-insoluble precursors; the carrier protein is essential for enzymic cholesterol synthesis. Liver microsomal enzymes contain a small amount of endogenous carrier protein, which is readily removed by washing or pu...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ritter MC,Dempsey ME

更新日期：1973-01-01 00:00:00

abstract：:H-2(q) mice (DBA/1) do not make an antibody response to a synthetic aminoacid polymer, (Glu, Ala,Tyr(10)), after an immunizing regimen that produces a good antibody response in mouse strains with other H-2 alleles. Their thymocytes, however, show evidence of recognizing this antigen since they synthesize DNA when they...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Gershon RK,Maurer PH,Merryman CF

更新日期：1973-01-01 00:00:00

abstract：:Ultraviolet (UV)-stimulated nonconservative DNA synthesis has been observed in E. coli rendered permeable to nucleoside triphosphates by exposure to toluene. This synthesis is detected in toluenized cells in which the background of UV-independent DNA synthesis is reduced by use of dnaB mutants temperature-sensitive fo...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Masker WE,Hanawalt PC

更新日期：1973-01-01 00:00:00

abstract：:If H denotes the classical Hilbert transform and Hu(x) = v(x), then the functions u(x) and v(x) are the values on the real axis of a pair of conjugate functions, harmonic in the upper half-plane. This note gives a generalization of the above concepts in which the Laplace equation Deltau = 0 is replaced by the Yukawa e...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Duffin RJ

更新日期：1972-12-01 00:00:00

abstract：:Five protease inhibitors with different modes of action were found to reduce the growth of transformed mouse (Py3T3, SV3T3, and 3T12) and hamster (PyBHK) cells. Some of these inhibitors caused the transformed cells to cease growth at saturation densities characteristic for nontransformed cells. The protease inhibitors...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Schnebli HP,Burger MM

更新日期：1972-12-01 00:00:00

abstract：:The structures of both oxidized (HP(ox)) and reduced (HP(red)) high-potential iron protein and of oxidized ferredoxin (Fd(ox)) have been partially refined at 2.0-A resolution by methods similar to those applied to the protein rubredoxin [Watenpaugh, K. D., Sieker, L. C., Herriott, J. R. & Jensen, L. H. (1971) Cold Spr...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Carter CW Jr,Kraut J,Freer ST,Alden RA,Sieker LC,Adman E,Jensen LH

更新日期：1972-12-01 00:00:00

abstract：:Recombination in some intervals of the map of phage lambda is associated with more DNA synthesis than in other intervals. Blockage of DNA synthesis by high temperature in a host temperature-sensitive for DNA synthesis results in the relative reduction of recombinant frequencies in those regions having the larger amoun...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Stahl FW,McMilin KD,Stahl MM,Nozu Y

更新日期：1972-12-01 00:00:00

abstract：:In vitro assembly of tobacco mosaic virus (TMV) from its constituent RNA and protein occurs in two steps: formation of the initial complex by interaction of the 5'-end of TMV-RNA with 20S protein aggregate, and growth of the helical rod by sequential addition of protein subunits.Such a process was also observed in the...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ono T,Inoue H,Okada Y

更新日期：1972-12-01 00:00:00

abstract：:The phenotype of several erythromycin-resistant mutants of Chlamydomonas reinhardi was further characterized in terms of the electrophoretic properties of their chloroplast ribosomal proteins. In mutant ery-M2d a single protein of the large (52 S) subunit has altered properties, which probably result from a change in ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Mets L,Bogorad L

更新日期：1972-12-01 00:00:00

abstract：:The structural requirements of E. coli formylmethionine tRNA for aminoacylation have been examined by chemical modification of the tRNA, followed by separation of the modified molecules into active and inactive components. Photooxidation of tRNA(fMet) at 50 degrees in the presence of methylene blue results in modifica...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Schulman LH

更新日期：1972-12-01 00:00:00

abstract：:To test whether a 30S ribosomal subunitformylmethionyl-tRNA-mRNA complex is an obligatory intermediate in protein synthesis, 70S ribosomes from Escherichia coli were crosslinked with the bifunctional imidoester, dimethylsuberimidate. Crosslinked ribosomes contained covelently joined 30S and 50S subunits, as judged by ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Slobin LI

更新日期：1972-12-01 00:00:00

abstract：:Absorbance changes of C-550 and cytochrome b(559), and fluorescence-yield changes were measured during irradiation of chloroplasts at -196 degrees . The photo-reduction of C-550 proceeded more rapidly than the photo-oxidation of cytochrome b(559), and the fluorescence-yield change had similar kinetics to the cytochrom...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Butler WL

更新日期：1972-11-01 00:00:00

abstract：:We have established empirical limits for the circular dichroism spectra appropriate for aqueous solutions of the B, C, and A forms of calf-thymus DNA and have analyzed DNA conformations in biological structures. The circular dichroism spectrum above 250 nm of purified calf-thymus chromatin can be satisfactorily accoun...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hanlon S,Johnson RS,Wolf B,Chan A

更新日期：1972-11-01 00:00:00

abstract：:Linear double-stranded molecules of the circularly permuted and terminally redundant DNA of Salmonella bacteriophage P22 have been converted to oligomeric products in the presence of polynucleotide ligase coded for by the coliphage T4. The reaction has been monitored by sucrose density-gradient centrifugation and elec...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Sgaramella V

更新日期：1972-11-01 00:00:00

abstract：:Addition of acetylcholine to growing cultures of mouse neuroblastoma cells induced a 37-fold increase in the specific activity of acetylcholinesterase (EC 3.1.1.7). Morphological changes, consisting of neurite-extensions, were also observed during the logarithmic phase of growth of cells stimulated with acetylcholine....

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Harkins J,Arsenault M,Schlesinger K,Kates J

更新日期：1972-11-01 00:00:00

abstract：:Prototrophic hybrids formed from an adenine-requiring Chinese hamster cell and human fibroblasts uniformly display new esterase activity that differs from that of either parental cell in electrophoretic mobility and substrate specificity. The hybrids that grew in the selective medium and possessed the new esterase act...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kao FT,Puck TT

更新日期：1972-11-01 00:00:00

abstract：:Glucose entry, as measured by 5-min uptake into the acid-soluble fraction, is enhanced 15-30 times by long-term (12-24 hr) hexose starvation of chick fibroblasts. The rate of galactose accumulation in the cells increases only 5 times under the same conditions of starvation. Several carbon and energy sources that were ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Martineau R,Kohlbacher M,Shaw SN,Amos H

更新日期：1972-11-01 00:00:00

abstract：:Human breast cancers contain an RNA related to that of mouse mammary tumor virus. In 79% of the breast malignancies examined, this type of RNA is a 70S-component encapsulated with RNA-instructed DNA polymerase in a particle possessing the density characteristics of RNA tumor viruses. Further, the DNA synthesized by th...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Axel R,Gulati SC,Spiegelman S

更新日期：1972-11-01 00:00:00

abstract：:DNA sequences in Neurospora crassa that code for ribosomal RNA have been isolated in a highly purified state by DNA-RNA hybridization. About 100 separate ribosomal RNA genes exist in each nucleus. These genes are composed of repeated sequences that are present about 100 times per nucleus. The individual members of thi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Chattopadhyay SK,Kohne DE,Dutta SK

更新日期：1972-11-01 00:00:00

abstract：:A procedure is described for selection of temperature-sensitive mutants affecting fatty-acid synthesis based upon radiation suicide of wild-type organisms by tritiated acetate selectively incorporated into fatty acids. At 37 degrees , two of the mutants extensively incorporate fatty-acid supplements provided in the me...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Harder ME,Beacham IR,Cronan JE Jr,Beacham K,Honegger JL,Silbert DF

更新日期：1972-11-01 00:00:00

abstract：:A mutant of E. coli defective in DNA polymerase II activity was isolated. Extracts had about 0.1% of the normal activity of the DNA polymerase. The effect of the mutation on the ability of cells to replicate DNA of various sources was analyzed. Mutant bacteria grow normally, at 41 degrees as well as at 30 degrees . Al...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hirota Y,Gefter M,Mindich L

更新日期：1972-11-01 00:00:00

abstract：:The usual way to compute Hartree-Fock type functions for molecules is by an expansion of the one-electron functions (molecular orbitals) in a linear combination of analytical functions (LCAO-MO-SCF, linear combination of atomic orbitals-Molecular Orbital-Self Consistent field). The expansion coefficients are obtained ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Clementi E

更新日期：1972-10-01 00:00:00

abstract：:Two continuous-suspension lymphocyte lines were isolated from the spleen and fibrosarcoma of a New Zealand Black female mouse. A C-type virus with a density of 1.16 g x cm(-3), 70S RNA, and RNA-directed DNA polymerase activity was isolated. The virus was infectious for NRK, NZB, (NZB x NZW)F(1), and (NZW x NZW)F(1) em...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Lerner RA,Jensen F,Kennel SJ,Dixon FJ,Des Roches G,Francke U

更新日期：1972-10-01 00:00:00

abstract：:Acquisition of acetylcholine receptors during differentiation of a clonal myoblast cell line was monitored with a neurotoxin isolated from venom of the Indian Cobra Naja naja. Toxin bound specifically and reversibly to acetylcholine receptors of the differentiated cells. Specificity of the binding reaction was assayed...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Patrick J,Heinemann SF,Lindstrom J,Schubert D,Steinbach JH

更新日期：1972-10-01 00:00:00

abstract：:In the normal development of retinotectal connections, the site in the tectum at which an optic fiber synapses is related to the position of its ganglion-cell body in the retina. How and when the ganglion cells acquire information about their positions is unknown, but the positional information that each ganglion cell...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hunt RK,Jacobson M

更新日期：1972-10-01 00:00:00

abstract：:The binding of a few molecules [1-6] of RNA bacteriophage coat protein to 1 molecule of RNA represses in vitro translation of the RNA synthetase cistron. Digestion of the complex, R17 coat protein-R17 RNA, by T1 RNase yields an RNA fragment bound to the coat protein. The nucleotide sequence of this fragment (59 residu...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Bernardi A,Spahr PF

更新日期：1972-10-01 00:00:00

abstract：:Evidence is presented that suggests that GTP (or 5'-guanylylmethylene diphosphonate) is not essential for either formation of an AUG-directed, initiation factor IF-2-dependent initiation complex on the 30S subunit or for positioning of fMet-tRNA on the peptidyl site. However, recycling of limiting amounts of IF-2 requ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Mazumder R

更新日期：1972-10-01 00:00:00

abstract：:In clinical trials comparing two treatments, one would often like to control the probability of erroneous decision while minimizing not the total sample size but the number of patients given the inferior treatment. To do this obviously requires that one use a datadependent allocation rule for the two treatments rather...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Flehinger BJ,Louis TA,Robbins H,Singer BH

更新日期：1972-10-01 00:00:00

abstract：:Necessary conditions are derived for a spherical vortex in a perfect fluid to be stationary in the case when the velocities depend on a single surface harmonic. The motion is indeterminate unless an additional condition is imposed. In the case when this condition is incompressibility, the equations are solved, yieldin...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Pekeris CL

更新日期：1972-09-01 00:00:00

abstract：:The mechanism of preferential transmission (i.e., maternal inheritance) of cytoplasmic genes was investigated with chloroplast DNA of Chlamydomonas as a model system. The behavior of nuclear and chloroplast DNAs were compared in the sexual cycle; DNAs from male and female parents were distinguished by labeling with (1...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Sager R,Lane D

更新日期：1972-09-01 00:00:00

abstract：:The immunoglobulin light chain is thought to be organized into two structural domains, the constant and the variable regions, linked by a switch region of lesser tertiary organization. Light chains of homogeneous rabbit antibodies to pneumococcal polysaccharides labeled with (125)I were subjected to trypsin digestion ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Poulsen K,Fraser KJ,Haber E

更新日期：1972-09-01 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

authors： Eyre DR,Glimcher MJ

更新日期：1972-09-01 00:00:00

abstract：:The nucleoside triphosphates ATP, GTP, TTP, and CTP induce conformational changes in histone IV at concentrations that are of the same magnitude as the histone concentration. The purine nucleoside triphosphates are much more effective than the pyrimidine nucleoside triphosphates. ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Wickett R,Isenberg I

更新日期：1972-09-01 00:00:00