scholarly journals USE OF GENOMIC EXCLUSION TO ISOLATE HEAT-SENSITIVE MUTANTS IN TETRAHYMENA

Genetics ◽  
1973 ◽  
Vol 73 (4) ◽  
pp. 543-559
Author(s):  
Eduardo Orias ◽  
Miriam Flacks
Keyword(s):  
Room Temperature ◽  
Axenic Culture ◽  
Tetrahymena Pyriformis ◽  
Recessive Mutation ◽  
Allelic Exclusion ◽  
Current Interest ◽  
Proteose Peptone ◽  
Abnormal Form ◽  
Mutant Strains ◽  
Peptone Medium

ABSTRACT We have used the abnormal form of conjugation known as "genomic exclusion" to isolate a collection of heat-sensitive mutants of Tetrahymena pyriformis, syngen 1. Growth at room temperature in bacterized medium and no growth at 40°C in the same medium was the criterion used for the isolation. The mutant strains were tested for growth in pure (axenic) culture in proteose peptone medium; of the 31 strains which grew normally at room temperature and not at 40°C in that medium, 21 also failed to grow at 37°C. Preliminary results of complementation tests suggest that most, if not all, the mutations are recessive and that a variety of genes was affected. A detailed genetic analysis was performed on one mutant (H9). The results are all consistent with the idea that the heat-sensitive phenotype of this mutant is determined by a single recessive mutation, designated ts-2. Heterozygotes ts-2/+ yield heat-sensitive segregants during vegetative growth; we interpret this finding as another example of allelic exclusion, a phenomenon universally encountered among heterozygotes in syngen 1 of T. pyriformis. Our results are discussed in the context of some questions of current interest in Tetrahymena genetics.

Serum-Induced Endocytic Vacuole in the Nonphagocytic Tetrahymena Pyriformis Strain NP1

1977 ◽  
Vol 35 ◽  
pp. 644-645
Author(s):  
L. J. Brenner ◽  
D. G. Osborne ◽  
B. L. Schumaker
Keyword(s):  
Electron Microscopy ◽  
Large Body ◽  
Tetrahymena Pyriformis ◽  
Metal Salts ◽  
Proteose Peptone ◽  
Transmission Electron ◽  
Food Vacuoles ◽  
Heavy Metal Salts ◽  
Normal Human ◽  
Peptone Medium

Tetrahymena pyriformis strains WH6, W, HSM, and GLC, after exposure to normal human serum, give rise to large membrane-bounded endocytic vacuoles, as visualized by transmission electron microscopy (TEM). These vacuoles do not resemble ordinary food vacuoles formed in the oral apparatus. Nor do they appear to be vacuoles containing protein concentrated from the serum: Albumin solutions induce a different type of vacuole (Brenner et al., 1976). The large bodies take a stain (PAS) that indicates the presence of polysaccharide. TEM micrographs show the presence of lipid in some of the large bodies. It is not yet known if these large body vacuoles are formed in the oral apparatus like food vacuoles or result from the fusion of pinocytic vacuoles.Although the mutant T. pyriformis strain, NP1, is unable to form a functional oral apparatus at 37° C and cannot form food vacuoles (Rasmussen and Orias, 1975), it multiplies in 2% proteose peptone medium supplemented with vitamins and heavy metal salts.

scholarly journals NUCLEOLAR AND BIOCHEMICAL CHANGES DURING UNBALANCED GROWTH OF TETRAHYMENA PYRIFORMIS

1965 ◽  
Vol 26 (3) ◽  
pp. 845-855 ◽  
Author(s):  
Ivan L. Cameron ◽  
E. Ernest Guile
Keyword(s):  
Protein Synthesis ◽  
Stationary Phase ◽  
Rna Synthesis ◽  
Morphological Changes ◽  
Synthetic Medium ◽  
Tetrahymena Pyriformis ◽  
Lag Phase ◽  
Proteose Peptone ◽  
Rna And Protein Synthesis ◽  
Peptone Medium

Numerous nucleoli can be observed in the macronucleus of the logarithmically growing ciliated protozoan Tetrahymena pyriformis; at late log phase the nucleoli aggregate and fuse. In stationary phase this fusion process continues, leaving a very few large vacuolated nuclear fusion bodies in the nucleus. When these stationary phase cells are placed into fresh enriched proteose peptone medium, the large fusion bodies begin to disaggregate during the 2.5-hour lag phase before cell division is initiated. By 3 to 6 hours after inoculation the appearance of the nucleoli in many cells returns to what it was in logarithmic cells. In view of the possible role of nucleoli in ribosome synthesis, attempts were made to correlate the morphological changes to changes in RNA and protein metabolism. The beginning of an increased RNA synthesis was concomitant with the beginning of disaggregation of the large fusion bodies into nucleoli, which was noticed in some cells by 1 hour after the return to fresh enriched proteose peptone medium. Increased protein synthesis then followed the increased RNA synthesis by 1 hour. The supply of RNA precursors (essential pyrimidines) were removed from cultures which were grown on a chemically defined synthetic medium, in order to study the relation between nucleolar fusion and synthesis of RNA and protein. Pyrimidine deprivation drastically curtailed RNA and protein synthesis, but did not cause fusion of nucleoli. When pyrimidines were added back to this culture medium, RNA synthesis was immediately stimulated and again preceded an increased protein synthesis by 1 hour. These studies suggest the involvement of unfused nucleoli in RNA and protein synthesis and demonstrate the extreme plasticity of nucleoli with respect to changes in their environment.

Cytochalasin B: Aspects of Phagocytosis in Nutrient Uptake in Tetrahymena

1974 ◽  
Vol 15 (2) ◽  
pp. 403-406
Author(s):  
ELSE K. HOFFMANN ◽  
L. RASMUSSEN ◽  
E. ZEUTHEN
Keyword(s):  
Nutrient Uptake ◽  
Nutrient Medium ◽  
Cytochalasin B ◽  
Tetrahymena Pyriformis ◽  
Food Vacuole ◽  
Vacuole Formation ◽  
Proteose Peptone ◽  
High Concentrations

Cytochalasin B (37 µg per ml) reduces the rate of food vacuole formation, i.e. the rate of phagocytosis, in Tetrahymena pyriformis. Cytochalasin B in this concentration suppresses multiplication rates in a nutrient medium consisting of 2 % proteose peptone, but multiplication is unaffected if this medium is supplemented with glucose and high concentrations of nucleosides. Thus nutrients in high concentrations circumvent the necessity for phagocytosis in Tetrahymena.

Die Bildung von Thymidintriphosphat bei Tetrahymena pyriformis (EHRENBERG) in statistischen und hitzesynchronisierten Kulturen / Formation of Thymidine Triphosphate in statistical and heat synchronized cultures of Tetrahymena pyriformis (EHRENBERG)

1970 ◽  
Vol 25 (5) ◽  
pp. 517-521 ◽  
Author(s):  
Manfred K. Grieshaber ◽  
Franz Duspiva
Keyword(s):  
Heat Treatment ◽  
Enzyme Activity ◽  
Stationary Phase ◽  
Dna Synthesis ◽  
Tetrahymena Pyriformis ◽  
Thymidylate Kinase ◽  
Proteose Peptone ◽  
Thymidine Triphosphate ◽  
Logarithmic Growth ◽  
Synchronized Cultures

The activity of thymidylate kinase is correlated with DNA-synthesis in Tetrahymena. During logarithmic growth it is twice as high as in the stationary phase; in cultures synchronized by heat treatment, the activity of the enzyme increases with the onset of DNA-synthesis. After application of 5 x 10-6 ᴍ Methotrexate, the activity of thymidylate kinase remains unchanged. There is, however, a dramatic increase in enzyme activity when the inhibition of transmethylations is circumvened by adding thymidine and proteose-peptone.

scholarly journals Bioactive fractions from Streptococcus macedonicus MBF 10-2 produced in an optimized plant-based peptone medium fermentation

2021 ◽  
Author(s):  
Amira Aulia Musnadi ◽  
Amarila Malik ◽  
Amalia Sitti Khayyira
Keyword(s):  
Micrococcus Luteus ◽  
Cell Mass ◽  
Carbon Sources ◽  
Antibacterial Properties ◽  
Maximum Growth ◽  
Diffusion Method ◽  
Proteose Peptone ◽  
Skin Patch ◽  
Antioxidant Potency ◽  
Peptone Medium

Background: Postbiotic fractions of several lactic acid bacteria have potential as microbial therapeutics for skin health and may also appeal to consumers who wish to avoid animal-based products. We aim to establish the optimum plant-peptone fermentation of Streptococcus macedonicus MBF10-2, which possess Bacteriocin Like-Inhibitory Substance activity in our previous study, to produce bacterial bioactive fractions. We evaluate their potential antibacterial and antioxidant actions, and as well assess the preliminary safety for human skin application. Methods: Fermentation was carried out by using plant peptone modified MRS, i.e., soy peptone and Vegitone, a non-animal-carbon sources that substitute proteose peptone in MRS medium. Fractions of MBF10-2 lysate and cell-free supernatant were collected and processed as follows, i.e. cell disruption, fraction separation and fractions freeze-drying. Fractions were confirm for antibacterial properties by the agar well diffusion method and assess for antioxidant activity using DPPH, while safety assessment was carried-out by skin patch assay. Result: Maximum growth of MBF10-2 achieved by fermentation in soy peptone- and in Vegitone-modified media was 9.00 and 7.99 g total cell mass, respectively. The antibacterial property of fractions was most effective against Micrococcus luteus T18. The lysate fraction exhibited a mild antioxidant potency (IC50 840 µg/mL), and all bioactive fractions were proven safe and non-allergenic for human skins. Conclusion: Strep. macedonicus MBF10-2 postbiotics bioactive fractions were indicated as being safe for topical application. This is the first report on the production of a safe Strep. macedonicus bioactive postbiotic possessing mild antibacterial and mild-to-weak antioxidant.   Keywords: antibacterial; antioxidant; lysate; soy peptone; Streptococcus macedonicus MBF 10-2

Influence of cadmium on Tetrahymena pyriformis in axenic culture

1981 ◽  
Vol 11 (3) ◽  
pp. 179-182 ◽  
Author(s):  
C. Houba ◽  
J. Remacle ◽  
F. Parmentier
Keyword(s):  
Axenic Culture ◽  
Tetrahymena Pyriformis

scholarly journals REGULATORY SEROTYPE MUTATIONS IN TETRAHYMENA PYRIFORMIS, SYNGEN 1

Genetics ◽  
1973 ◽  
Vol 74 (1) ◽  
pp. 81-106
Author(s):  
F P Doerder
Keyword(s):  
Mutant Allele ◽  
Tetrahymena Pyriformis ◽  
Surface Antigens ◽  
Allelic Exclusion ◽  
T Antigens ◽  
Normal Pattern ◽  
Immobilization Antigen ◽  
Chromosome Fragments ◽  
Recessive Mutant ◽  
H Serotypes

ABSTRACT A method utilizing allelic exclusion has been developed to isolate mutants of Tetrahymena pyriformis, syngen 1, in which the normal pattern of expression of mutally exclusive surface antigens is altered. Cells homozygous for the recessive mutant allele R-1r do not express the L, H and T serotypes when grown under conditions appropriate for their expression. Rather, a new immobilization antigen, r, is expressed. Cells homozygous for the recessive mutant allele R-3r also express the r antigen instead of H serotypes, but are normal in their expression of T antigens. Genetic analyses show that R-1 and R-3 are not closely linked, that R-1 is linked to T by 9.3 units, and that R-3 may be loosely linked to the mt locus. Different linkage values were obtained, however, when different inbred laboratory strains were used, suggesting the possible existence of crossover modifying genes. The rates of assortment of R-1R/R-1r and R-3R/R-3r heterozygotes into pure sublines expressing either H or r serotypes are close to the values observed for the differentiation of heterozygotes at other loci. The data confirm the previous observation that genetic coupling relationships are not maintained in macronuclear phenotypes and are consistent with the hypothesis that the macronucleus contains 45 assorting subunits. The assortment of the double heterozygote R-1R/R-1r, R-3R/R-3r at Rf=0.0112 suggests that the units of assortment are not individual genetic loci or chromosome fragments, but that the units may be complete genomes.

scholarly journals A New Record of Oxytricha granulifera granulifera Foissner and Adam, 1983 (Protozoa, Ciliophora, Oxytrichidae) From a Hot Spring in Iceland, With Notes on Its Abnormal Form During Cultivation

2021 ◽  
Vol 8 ◽  
Author(s):  
Rong Zhu ◽  
Zhishuai Qu ◽  
Qi Zhang ◽  
Sabine Filker ◽  
Thorsten Stoeck ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hot Spring ◽  
Phylogenetic Analyses ◽  
Morphological Characteristics ◽  
Ssu Rdna ◽  
Long Period ◽  
Abnormal Form ◽  
Abnormal Cells ◽  
Protozoa Ciliophora ◽  
Resting Cysts

We isolated a population of Oxytricha granulifera granuliferaFoissner and Adam (1983) from a hot spring in Iceland. The pure culture of this isolate was established at room temperature in the laboratory. This allowed for a detailed investigation, informed by integrated approaches, of the isolate’s morphology and morphogenesis, as well as molecular phylogeny. Results showed that the morphological and morphogenetic characteristics of the Iceland population are consistent with those of other populations. During the 3-year long period of laboratory cultivation, some abnormal individuals appeared repeatedly in the culture system. Interestingly, the morphological characteristics of these abnormal cells were rather stable, and were as follows: 1) body slender and elliptical-shaped; 2) remarkably shortened adoral zone and significantly reduced number of adoral membranelles; and 3) loss of undulating membranes. Resting cysts, binary fission and conjugate reproduction were not found in abnormal specimens. Although the morphology of abnormal individuals changed significantly, the sequences of the SSU rDNA of the normal and abnormal morphotypes were the same. Phylogenetic analyses showed that the two morphotypes clustered in a clade with other populations of O. granulifera granulifera.

scholarly journals Secretion of lysosomal hydrolases by stimulated and nonstimulated macrophages.

1978 ◽  
Vol 148 (2) ◽  
pp. 435-450 ◽  
Author(s):  
J Schnyder ◽  
M Baggiolini
Keyword(s):  
Plasminogen Activator ◽  
Lysosomal Enzyme ◽  
Peritoneal Macrophages ◽  
Enzyme Secretion ◽  
Wall Material ◽  
Lysosomal Hydrolases ◽  
Intracellular Enzyme ◽  
Proteose Peptone ◽  
Peptone Medium

Peritoneal macrophages were obtained from untreated mice and from mice treated with thioglycollate medium (TA), proteose peptone medium (PP), or a suspension of streptococcus A cell wall material (SA). The biochemical and secretory properties of these cells in long term cultures (up to 2 wk) were compared. TA-elicited macrophages contained more protein, lactate dehydrogenase, lysosomal hydrolases, and in particular, more plasminogen activator than the other cells studied. All types of macrophages studied were found to release considerable amounts of lysosomal hydrolases (beta-glucuronidase, N-acetyl-beta-glucosaminidase, alpha-mannosidase, and acid phosphatase) into the medium. Release was independent of phagocytosis and must, therefore, be regarded as true secretion. In both elicited and nonelicited macrophages, the rates of lysosomal enzyme secretion were virtually identical in the presence and in the absence of serum, and they were not enhanced by increasing serum concentrations. Lysosomal enzyme secretion in macrophages appears to depend on protein synthesis, since it was blocked by low concentrations of cycloheximide which neither affected cell viability nor lowered the intracellular enzyme levels. The amounts of lysosomal hydrolases secreted were highest in TA-elicited macrophages. The rates of secretion of PP- or SA-elicited and of nonelicited macrophages were about one-fourth of that of the TA-elicited cells. This difference, although significant, is much smaller than that observed for the secretion of plasminogen activator which was 20-50 times higher in TA-elicited cells. Acid glycosidases were also found in the peritoneal lavage media used for cell harvesting from both treated and nontreated mice. This indicates that active secretion of lysosomal hydrolases may be an in vivo property of the macrophage.

scholarly journals STUDIES ON THE NUTRITION OF HEMOPHILUS INFLUENZAE

1942 ◽  
Vol 76 (3) ◽  
pp. 241-252 ◽  
Author(s):  
Charles L. Hoagland ◽  
S. M. Ward ◽  
Helena Gilder ◽  
Robert E. Shank
Keyword(s):  
Metabolic Activity ◽  
Sodium Nitrate ◽  
Quantitative Method ◽  
Quantitative Relationship ◽  
Specific Factor ◽  
Optimum Growth ◽  
The Past ◽  
Proteose Peptone ◽  
Peptone Medium

The metabolic activity of H. influenzae can be followed quantitatively by measurement of the nitrite produced in a medium containing 0.2 per cent potassium or sodium nitrate. When X-factor, or hemin, and other specific substances required for the optimum growth of H. influenzae, are present in excess, the nitrite produced by this organism is quantitatively related to the concentration of V-factor, or total coenzyme. This quantitative relationship has been demonstrated for five strains of H. influenzae. It has been shown that various media, which in the past have been used for the determination of coenzyme by growth of H. influenzae, have in many instances been deficient in X-factor and that this substance rather than coenzyme has been the specific factor limiting growth. When 0.5 per cent blood is added to a basal proteose-peptone medium the specific requirements for optimum growth and metabolic activity of H. influenzae, other than coenzyme, are met, and a large number of specific biocatalysts and nutritive substances added to this medium are without effect in stimulating further growth. The foregoing studies have formed the basis for a quantitative method for the determination of total coenzyme in blood and tissue. This method is being described elsewhere.

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