Effect Of P-fluorophenylalanine Research Articles

Variation in the Chromosome number of cultured shoot tip of Vitis spp. by p-fluorophenylalanine treatment.

The effect of p-fluorophenylalanine (PFP) on the induction of variations in the chromosome number was investigated in cultured shoot tips of Vitis clones, including triploid and tetraploid cultivars and interspecific hybrids. A higher concentration (400 μM) of PFP inhibited the growth of the shoot tips. The abnormal mitoses and the variations in the chromosome number including the induction of haploid and aneuploid cells were observed in the shoot tip cells treated with PFP. Variations in the chromosome number were also observed in the root tip cells of regenerated plants after PFP treatment. However, most of cells with abnormal chromosome number co-existed with normal cells. The average perc6ntage of the anormal cells was about 1.0% among total observed cells of all the clones examined. In most of the cases the abnormal chromosome number observed in the roots was euploids, regardless of the ploidy level of the clones examined. There were fewer aneuploids in root cells than in the shoot tip cells. In all the experiments, two variants (about 0.3% of the plants checked) had large sectors with reduced numbers of chromosomes in the shoots. One was a triploid-tetraploid variant from the tetraploid cultivar Kyoho, and the other was a diploid-triploid variant from the triploid clone KC-1.

Effect of p-fluorophenylalanine and amino acid derivatives on variation of somatic chromosome number in grape root tip cells.

To analyze the pattern of variations in chromosome number of root tip cells of grape seedlings induced by p-fluorophenylalanine (PFP), the effectiveness of treatment with phenylalanine derivatives and amino acid analogs during germination period was investigated. The frequency of cells showing variations in the chromosome number was significantly correlated with the frequency of occurrence of abnormal mitosis, but not with seed germination, seedling growth nor mitotic activity in the root tips. Compounds closely related to phenylalanines, such as those obtained by substitution on the phenyl ring, the replacement of the phenyl ring by a thienyl ring, or the methylation on the side chain, were effective, though less than PFP. A comparison of the stereoisomers of PFP showed that L-PFP induced a reduction of the chromosome number, unlike the D-enantoimer. N-acetyl-PFP, which was a modification of the amino group of PFP, did not induce chromosome variation. Among eight analogs of other amino acids, only m-fluorotyrosine and 5-fluorotryptophan induced variation in the chromosome number to the same extent as PFP.

The effect of p-fluorophenylalanine on the frequency of aneuploid meiotic products in Sordaria brevicollis

The effect of p-fluorophenylalanine on the frequency of aneuploid meiotic products in Sordaria brevicollis

The Dynamics of Cell Proliferation in Haploid and Diploid Tissues of Nicotiana tabacum

Summary Haploid plants of Nicotiana tabacum were obtained by culturing anthers at the microspore stage. Explants of pith tissue from haploid as well as diploid plants were grown in vitro, and changes in cell number, cell size, and fresh weight were determined over a 16-day period. In the tissue from diploid plants a decrease in cell size was seen after the eighth day in culture, but the tissues from haploid plants exhibited a slight increase in cell size. Spectrophotometric determination of deoxyribonucleic acid (DNA) was made to investigate the time course of DNA synthesis during cell proliferation and culture. A wide range of ploidy levels was seen in the fresh pith tissues of both haploid and diploid .plants. Culture of these tissues resulted in increased levels of ploidy in a large proportion of the cells. In general, cells with lower DNA content per nucleus entered the cell cycle sooner than those with a higher amount. After an extended period of time in culture both haploid and diploid cxplants showed a variety of polyploid and aneuploid cells. The effects of pfluorophenylalanine (PFP) on explant growth and ploidy were tested. PFP was inhibitory to the growth of all cells, but haploid cells were inhibited slightly less than those of higher ploidy. Spectrophotometric data are presented to demonstrate that PFP can be used to maintain - or even increase - the population of haploid cells in tissue cultures derived from haploid plants of tobacco.

Effects of p-fluorophenylalanine on the induction of mutations in bacteriophage T4 : II. Nitrous acid mutagenesis

The effects of p-fluorophenylalanine (PFPA), an analogue of phenylalanine (PHE), on the potency and the specificity of nitrous acid (NA) mutagenesis in the r system of bacteriophage T4 were measured. 1. (a) Forward mutation The frequencies of NA-induced r mutants were approximately doubled when mutagenized phage infected E. coli B in the presence of the analogue compared to controls where PHE was substituted for PFPA, or where no amino acid was added. The spontaneous forward mutation frequency was not affected by the analogue, nor was the specificity of the NA mutagenesis. 2. (b) Reverse mutation The frequency of spontaneous and NA-induced reversion of an rII transition mutant was unaffected by PFPA if the phage were plated direct on the restrictive host after mutagenesis. However, if mutagenized phage were first allowed a cycle of growth in the presence of PFPA the induced reversion frequency was increased about 3-fold compared to the control.

Effects of p-fluorophenylalanine on the induction of mutations in bacteriophage T4 II. Nitrous acid mutagenesis

The effects of p -fluorophenylalanine (PFPA), an analogue of phenylalanine (PHE), on the potency and the specificity of nitrous acid (NA) mutagenesis in the r system of bacteriophage T4 were measured. 1. (a) Forward mutation The frequencies of NA-induced r mutants were approximately doubled when mutagenized phage infected E. coli B in the presence of the analogue compared to controls where PHE was substituted for PFPA, or where no amino acid was added. The spontaneous forward mutation frequency was not affected by the analogue, nor was the specificity of the NA mutagenesis. 2. (b) Reverse mutation The frequency of spontaneous and NA-induced reversion of an rII transition mutant was unaffected by PFPA if the phage were plated direct on the restrictive host after mutagenesis. However, if mutagenized phage were first allowed a cycle of growth in the presence of PFPA the induced reversion frequency was increased about 3-fold compared to the control.

Effects of p-fluorophenylalanine on the induction of mutations in bacteriophage T4 : I. 5-Bromouracil mutagenesis

The amino acid analogue p-fluorophenylalanine (PFPA) was found to have no mutagenic activity in the r system of bacteriophage T4. However, under standard conditions for 5-bromouracil (5-BU) mutagenesis, PFPA depressed the induced frequencies for both forward and reverse mutations. When the folate antagonist sulphanilamide (SU) was omitted from the mutagenic treatment medium or when it was replaced by Trimethoprim (TM), another folate antagonist, this depressive effect was abolished. It was proposed that PFPA alleviated the inhibitory action of SU.

Effects of p-fluorophenylalanine on the induction of mutations in bacteriophage T4 I. 5-bromouracil mutagenesis

The amino acid analogue p -fluorophenylalanine (PFPA) was found to have no mutagenic activity in the r system of bacteriophage T4. However, under standard conditions for 5-bromouracil (5-BU) mutagenesis, PFPA depressed the induced frequencies for both forward and reverse mutations. When the folate antagonist sulphanilamide (SU) was omitted from the mutagenic treatment medium or when it was replaced by Trimethoprim (TM), another folate antagonist, this depressive effect was abolished. It was proposed that PFPA alleviated the inhibitory action of SU.

Effects of p-fluorophenylalanine (PFP) on the growth of cell lines differing in ploidy and derived from Nicotiana sylvestris

The growth inhibitory activity of p-fluorophenylalanine (PFP) (concentration range 25–75 μg/ml) has been tested on callus initiation and early callus growth and on suspension cultures derived from one diploid and three haploid plants of Nicotiana sylvestris. All the culture lines contained cells at more than one level of ploidy; the cultures of haploid origin contained a high level of haploid cells. Under conditions of partial growth inhibition by PFP there was, despite the reduced sensitivity of the cultures of haploid origin, no preferential growth of haploid cells in these cultures. Genotype not ploidy level determined sensitivity to growth inhibition by PFP.

Effects of antimetabolites on production of the phytoalexin pisatin

The effect of p-fluorophenylalanine, puromycin dihydrochloride, cycloheximide and patulin on the synthesis of pisatin was investigated. Their actions differed. In some cases pisatin synthesis was stimulated and in others it was inhibited. These incompatible effects make any definite conclusions as to whether protein synthesis is required for pisatin synthesis impossible.

The effects of some amino acid analogs on mitosis and the cell cycle

1. 1. Studies of the effects of several amino acid analogs on protein synthesis, mitosis and the cell cycle were performed. 2. 2. It was found that all of these analogs at appropriate concentrations could severely affect the duration of mitosis but only the phenylalanine analogs, and especially p-fluorophenylalanine, were shown to greatly prolong the duration of metaphase with little or relatively minor effects on the duration of the rest of the mitotic cycle. 3. 3. Of all the analogs studied, only 2-β-thienylalanine was observed to produce morphologically abnormal spindles. 4. 4. Analyses of the kinetics of the effects of 2-β-thienylalanine and p-chlorophenylalanine indicated that the data are consistent with previous findings on the effects of p-fluorophenylalanine which indicated that some mitosis-related protein is synthesized during a short period prior to mitosis and is conserved and reutilized by daughter cells for their own subsequent divisions.

Genetic control of DNA specificity in Pseudomonas aeruginosa.

Genotypic and phenotypic changes of HCM inP. aeruginosaare due to a variety of causes. In addition to interstrain genetic differences and the semi-permanent effects of growth at 43°C, mutations affecting both restriction and modification have been isolated by direct selection and through the pleiotropic effects ofp–fluorophenylalanine resistance mutations. It is suggested that some of these changes affecting HCM may be taking place through alterations of the ribosomes.

Effect of p-fluorophenylalanine on radiation sensitivity in Escherichia coli.

An increase in the number of survivors, after γ-irradiation in the "physiological" dose range, is obtained when cultures of Escherichia coli, wild type, are grown in the presence of p-fluorophenylalanine (FPA). In contrast to this result, exposure to FPA sensitizes cells of the radiation-resistant mutant, E. coli 6γ, to γ-irradiation. The addition of FPA to a logarithmically growing culture of E. coli wild type reduces the rate of protein synthesis relative to DNA synthesis whereas, in E. coli 6γ, protein synthesis is less sensitive to FPA-inhibition than is deoxyribonucleic acid (DNA) synthesis. The results are explained by assuming that augmented radioresistance in FPA-exposed cultures of E. coli wild type reflects accumulation of cells that have terminated one round of DNA replication and not initiated a new one, analogous to the effects of amino acid starvation in bacterial cells. FPA is suggested not to act in this way in E. coli 6γ.

The effect of p-fluorophenylalanine on nucleic acid biosynthesis and cell division in Escherichia coli.

The effect of p-fluorophenylalanine on nucleic acid biosynthesis and cell division in Escherichia coli.

Further studies on the effect of p-fluorophenylalanine and puromycin on polio virus replication.

Annals of the New York Academy of SciencesVolume 130, Issue 1 p. 282-290 FURTHER STUDIES ON THE EFFECT OF p-FLUOROPHENYLALANINE AND PUROMYCIN ON POLIO VIRUS REPLICATION§ M. D. Scharff, M. D. Scharff Department of Cell Biology and Medicine, Albert Einstein College of Medicine, New York, N. Y.Search for more papers by this authorD. F. Summers, D. F. Summers Department of Biochemistry and Medicine, Albert Einstein College of Medicine, New York, N. Y.Search for more papers by this authorL. Levintow, L. Levintow Laboratory of Biology of Viruses, National Institute of Allergy and Infectious Diseases National Institutes of Health, Bethesda, Md.Search for more papers by this author M. D. Scharff, M. D. Scharff Department of Cell Biology and Medicine, Albert Einstein College of Medicine, New York, N. Y.Search for more papers by this authorD. F. Summers, D. F. Summers Department of Biochemistry and Medicine, Albert Einstein College of Medicine, New York, N. Y.Search for more papers by this authorL. Levintow, L. Levintow Laboratory of Biology of Viruses, National Institute of Allergy and Infectious Diseases National Institutes of Health, Bethesda, Md.Search for more papers by this author First published: July 1965 https://doi.org/10.1111/j.1749-6632.1965.tb12561.xCitations: 11 § Supported in part by grants from the National Instiutes of Health, Numbers AI-05231 and AI-04153, and National Science Foundation, Number GB-984. Dr. Scharff is a recipient of a Career Development Award from the National Institutes of Health. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume130, Issue1Antiviral SubstancesJuly 1965Pages 282-290 RelatedInformation

Effect of p-Fluorophenylalanine on the synthesis of vaccinia virus

The effect of the amino acid analog FPA on vaccinia virus replication in HeLa cells was investigated. By varying the dose of FPA or the time after infection at which the analog was added to cultures, it was possible to inhibit differentially the synthesis of viral components in vaccinia-infected cells. When sufficient FPA was added to cultures at the time of infection, the synthesis of viral DNA, NP antigen, infectious virus, and HA was inhibited. The inhibition of synthesis of LS antigen under all conditions studied was only partial. FPA added to cultures at 6 or more hours post-infection did not inhibit production of viral antigens or infectious virus. The inhibition was reversed by PA added with the FPA, but PA added at later times was progressively less effective in restoring the ability of inhibited infected cultures to produce virus. The proportion of nuclei incorporating thymidine-H 3 was decreased in cultures infected with vaccinia virus. This decrease was not seen in cultures receiving FPA at the time of infection.

Effects of p-fluorophenylalanine on lactose-induced β-galactosidase synthesis in resting-cell suspensions of Escherichia coli

With lactose as the inducer, p-fluorophenylalanine retarded β-galactosidase induction in Escherichia coli B during the first hour but permitted the level of activity to exceed that of controls by 2–3 times after 3 hours. Incorporation of the analog into protein was demonstrated both with unlabeled and with fluorophenylalanine-C 14. Decreasing the lactose concentration in the absence of analog had no effect on the total level of enzyme activity, but in the presence of analog a progressive increase in the initial lag period was observed. Preinduced cells showed no lag in enzyme formation upon addition of analog but still exhibited a stimulatory response. No lag was evident when thiomethyl-β- d-galactoside was employed as inducer, although the analog did cause a reduced level of enzyme activity. Decreasing the analog concentration at a constant level of lactose shortened the lag period and enhanced the stimulatory response. These and other data suggest that (1) the initial effect of analog is to retard formation of active galactoside permease, (2) analog supplies nitrogen, either directly or indirectly, thus forestalling onset of end-product repression of β-galactosidase formation, and (3) enzymic activity of β-galactosidase formed might be reduced in proportion to the amount of analog incorporated in the enzyme.

Effect of p-fluorophenylalanine and puromycin on the replication of poliovirus

The presence of an appropriate concentration of p-fluorophenylalanine in the medium of infected HeLa cells prevents the maturation of poliovirus, but permits the synthesis of infectious RNA. When the inhibition is released by the addition of phenylalanine, a second cycle of viral RNA is formed coordinately with viral protein, and only this latter RNA appears in the mature virus particles. Puromycin, added to an infected culture early in the latent period, prevents both maturation and RNA synthesis; addition of puromycin near the end of the latent period permits limited synthesis of RNA. The data suggest that protein synthesis is necessary to permit the replication of RNA and provide some evidence for the necessity for protein synthesis early in the infectious cycle.

Effect of p-fluorophenylalanine of psittacosis virus in tissue cultures.

Tanami, Yoh (University of Texas Medical Branch, Galveston) and Morris Pollard. Effect of p-fluorophenylalanine on psittacosis virus in tissue cultures. J. Bacteriol. 83:437-442. 1962.-The inhibitory effect of p-fluorophenylalanine (FPA) on maturation of psittacosis virus was investigated, with attention to the time sequence of viral protein synthesis. Extracellular virus particles were not inactivated by FPA at a concentration of 100 mug per ml, at which level it interfered with maturation of intracellular virus. When FPA was added to infected tissue cultures earlier than 15 hr after infection, intracellular virus maturation was suppressed. However, when FPA was added after 15 hr, infective virus was produced, which indicates that the synthesis of a FPA-sensitive virus precursor (presumably viral protein) had already occurred. A latent ("dormant") infection of psittacosis virus, established in a medium deficient in phenylalanine and tyrosine, was also investigated.

Effect of p-Fluorophenylalanine on the Multiplication of Foot-and-Mouth Disease Virus

MANY amino-acid analogues are known to prevent protein synthesis. p-Fluorophenylalanine in particular has been shown to inhibit synthesis by competition with phenylalanine. The growth of several animal viruses is inhibited by the addition of this analogue to the growth medium (for example, the viruses of poliomyelitis1, influenza2, fowl plague3 and Western equine encephalomyelitis4). In the case of polio virus and influenza virus, the effect of p-fluorophenylalanine on the infectivity and haemagglutinating activity, respectively, was studied. A more detailed examination of the effect of the inhibitor on the synthesis of the sub-units of fowl plague virus and Western equine encephalomyelitis virus has shown that information can be obtained on the manner in which the complete virus particles are formed. The present communication describes the effect of p-fluorophenylalanine on the synthesis of the infective component and viral ribonucleic acid of foot-and-mouth disease virus.