Oligonucleotide fingerprints of RNA species obtained from rhabdoviruses belonging to the vesicular stomatitis virus subgroup.

The relationships among the genomes of various rhabdoviruses belonging to the vesicular stomatitis virus subgroup were analyzed by an oligonucleotide fingerprinting technique. Of 10 vesicular stomatitis viruses, Indiana serotype (VSV Indiana), obtained from various sources, either no, few, or many differences were observed in the oligonucleotide fingerprints of the 42S RNA species extracted from standard B virions. Analyses of the oligonucleotides obtained from RNA extracted from three separate preparations of VSV Indiana defective T particles showed that their RNAs contain fewer oligonucleotides than the corresponding B particle RNA species. The fingerprints of RNA obtained from five VSV New Jersey serotype viruses were easily distinguished from those of the VSV Indiana isolates. Three of the VSV New Jersey RNA fingerprints were similar to each other but quite different from those of the other two viruses. The RNA fingerprints of two Chandipura virus isolates (one obtained from India and one from Nigeria) were also unique, whereas the fingerprint of Cocal virus RNA was unlike that of the serologically related VSV Indiana.     

Nitrogen catabolite repression in a glutamate auxotroph of Saccharomyces cerevisiae

The biosynthesis of asparaginase II in Saccharomyces cerevisiae is subject to nitrogen catabolite repression. In the present study we examined the physiological effects of glutamate auxotrophy on cellular metabolism and on the nitrogen catabolite repression of asparaginase II. Glutamate auxotrophic cells, incubated without a glutamate supplement, had a diminished internal pool of alpha-ketoglutarate and a concomitant inability to equilibrate ammonium ion with alpha-amino nitrogen. In the glutamate auxotroph, asparaginase II biosynthesis exhibited a decreased sensitivity to nitrogen catabolite repression by ammonium ion but normal sensitivity to nitrogen catabolite repression by all amino acids tested.     

Genetic structure of the Queckchi Indians. Dental microdifferentiation.

Nine oral morphologic characters were investigated. Their frequencies are compared with those published for other populations. The possibility of using such characters to estimate genetic distance between populations is discussed and the conclusion is reached that, although previous studies have suggested this to be a valid approach, further studies testing this subject are needed.     

Automated assay of phosphohydrolases by measuring the released phosphate without deproteinization.

We describe an automated determination of inorganic phosphate in the presence of proteins and its application for the assay of NaK-ATPase (EC 3.6.1.3) and other insoluble phosphohydrolases. After incubation the enzyme reaction is stopped at neutral pH with 3.3% (w/v) sodium dodecyl sulfate plus 30 mm EDTA (final concentration). The released phosphate is measured on the Technicon Autoanalyzer as phosphomolybdate reduced with ferrous ammonium sulfate and thiourea to molybdenum blue. EDTA enhances color development and solubilization of the proteins. The reagents are stable at room temperature and are formulated from cheap, common chemicals.     

Limits of artificial selection under unbalanced mating systems

Summary The influence of unbalanced mating systems — factorial mating (FM) and random loss of families after a full diallel crossing (RS) — on the ultimate probability of gene fixation (u()) and the time required to fix or lose a gene (t()) are investigated. The average u() of these systems is smaller than that of random mating, and the range of u() for a given initial parental genotype combination is very large (close to one for most initial genotypic combinations). The average u() of different parental genotypic combinations of a given gene frequency are different. These systems accelerate the t().This article was written and prepared by U.S. Government employees on official time, and it is therefore in the public domain     

A fluorescent derivative of ribosomal protein S18 which permits direct observation of messenger RNA binding.

70 S Escherichia coli ribosomes were reacted with the fluorescent dye N-(iodoacetylaminoethyl)-5-naphthylamine-1-sulfonic acid for 10 min under mild conditions. The resulting ribosomes were fully active. 30 S subunits isolated from these particles were also fully active. They contain approximately 0.7 eq of fluorescent dye. Nearly all of it is attached to protein S18. Competitive reaction with N-ethylmaleimide implies that the fluorescent dye is located at cysteine 10 of the protein. The labeled 30 S particles will recombine with 50 S subunits to form stable 70 S particles. Thus the procedures we have developed allow the large scale preparation of an active fluorescent conjugate of the 70 S ribosome. The fluorescence of the 70 S particles is sensitive to the binding of mRNA, showing both quenching and a shift in emission spectra. Thus it affords a simple way to quantitate mRNA binding directly. In pilot studies without tRNA, the binding constant of the initiation triplet codon adenylyl-(3' leads to 5')-uridylyl-(3' leads to 5')-guanosine to 70 S ribosome was found to be an order of magnitude larger than that of polyuridylic acid.     

The configuration and location of the ribosidic linkage in the prosthetic group of citrate lyase (Klebsiella aerogenes).

The structure of the prosthetic group of citrate lyase (Klebsiella aerogenes) was studied by nuclear magnetic resonance and mass spectrometry. The spectra at 360 MHz of the nucleoside moiety (2'-ribosyladenosine) show the absence of 2'-hydroxyl proton, thus confirming the 2' position as the site of attachment of the second ribose moiety to the dephospho-CoA. This glycosidic linkage is found to be alpha(1" leads to 2') and is identical to that of poly(ADP-ribose). Studies of permethylation products by mass spectrometry support the above conclusion regarding the location of the ribosidic linkage.     

Synthesis of 4-triazolopyrimidinone nucleotide and its application in synthesis of 5-methylcytosine-containing oligodeoxyribonucleotides.

5'-0-Dimethoxytritylthymidine (2) was phosphorylated and base-modified simultaneously to yield the 4-triazolopyrimidinone nucleotide (3). Coupling between (3) and other common deoxyribonucleotides gave a fully protected nonamer (4). Deblocking under different conditions yielded the nonamer as phosphodiester with concomitant conversion of 4-triazolopyrimidinone to 5-methylcytosine (aqueous ammonia) or thymine (N1,N1,N3,N3-tetramethyl-guanidinium syn-4-nitrobenzaldoximate solution).     

Nutritional and karyotypic characterization of a haploid cell culture ofDaucus carota

Summary The purpose of this study was to optimize growth conditions for a strain of haploid carrot callus and to follow its karyotypic changes in a long span of time. The strain has been maintained in liquid suspension since September 1977. It has remained predominantly haploid in its karyotype since that time. The original explant was initiated and subsequently subcultured in Gamborg's B5 medium. The components of the B5 medium were omitted one at a time and sequentially added back to determine their minimum, optimum, and maximum nontoxic concentrations. These changes were made in the original formula: the addition of an organic buffering agent and an increase in the iron and other micronutrient concentrations. Using this slightly modified B5 medium, we assessed the effect on growth by single additions of amino acids, different carbon sources, growth regulators, and vitamins. No improvement in plating efficiency resulted from addition of any of these compounds. We conclude that there are factors limiting the plating efficiency of the haploid cells other than these tested, or that single additions will not make a discernible difference, or that growth promoting factors cannot be exogenously supplemented to cultured cells.     

Purification of chicken brain choline acetyltransferase

Chicken brain choline acetyltransferase was purified to homogeneity using ammonium sulfate fractionation, followed by chromatography on DEAE-Sephadex (A-25), hydroxyapatite, Sephadex G-150, immunoabsorption and Sepharose-CoA columns. A purification of 3500-fold was achieved and the final preparation had a specific activity of 2:32 μmol acetylcholine formed per minute per milligram protein. The purified chicken choline acetyltransferase migrated as a single band on polyacrylamide gel electrophoresis in the presence and absence of sodium deodecyl sulfate. The native enzyme, with a molecular weight of 67,000 daltons, consists of two subunits of identical molecular weight. Chicken choline acetyltransferase has a sharp pH optimum of 7.4. It is activated by sodium chloride and potassium chloride but inhibited by cupric ion and N-ethylmaleimide.