Selection of spontaneous mutants by inositol starvation in yeast

1975 ◽  
Vol 143 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Susan A. Henry ◽  
Thomas F. Donahue ◽  
Michael R. Culbertson
Keyword(s):  
Spontaneous Mutants ◽  
Selection Of

scholarly journals Radiation-induced alcohol dehydrogenase mutants in maize following allyl alcohol selection of pollen

1978 ◽  
Vol 31 (2) ◽  
pp. 107-129 ◽  
Author(s):  
Michael Freeling ◽  
David S. K. Cheng
Keyword(s):  
Alcohol Dehydrogenase ◽  
Allyl Alcohol ◽  
Mutational Analysis ◽  
Mutagenic Action ◽  
X Rays ◽  
Radiation Induced ◽  
Allyl Alcohol Selection ◽  
Spontaneous Mutants ◽  
Alcohol Dehydrogenase 1 ◽  
Selection Of

SUMMARYThe alcohol dehydrogenase-1 gene in maize presents advantages for mutational analysis. Foremost among these is the ability to chemically select ADH-negative and ADH-low gametophytes owing to their resistance to allyl alcohol vapour. Immature tassels were irradiated with either 220 kV X-rays or 400 MeV/amu accelerated neon-ions; spontaneous mutants were also selected and recovered. RBE for neon-20 was about 5. A total of 70 presumptive mutants were placed into one of four classes on the basis of allozyme profiles following electrophoresis and ADH staining: (A) dysfunction, (B) underproducer, (C) overproducer, and (D) up-Adh2 gene. Mutants have been recovered and confirmed in the first three classes. These include two male-transmissible deletion-type lesions induced by X-rays, five underproducer transpositions and one overproducer transposition induced by neon-20. Certain of the neoninduced alleles are unstable in their expression. All 70 mutants are chromosomal aberrations; no intragenic lesions were recovered although our experimental design would have preferentially recovered them if they had occurred.The Discussion considers the mutagenic action of ionizing radiation, and especially the well-documented differences between maize and Drosophila data. In particular, the effect of these chromosome derangements on the ‘programmable’ component(s) of the Adhl cistron is discussed.

SERIAL IN VIVO PASSAGE OF THE ENTOMOPATHOGENIC HYPHOMYCETE TOLYPOCLADIUM CYLINDROSPORUM IN MOSQUITOES

1987 ◽  
Vol 119 (6) ◽  
pp. 599-601 ◽  
Author(s):  
Mark S. Goettel
Keyword(s):  
Beauveria Bassiana ◽  
Single Spore ◽  
Selection Pressures ◽  
Entomogenous Fungi ◽  
Fungal Strains ◽  
Successive Passage ◽  
Entomopathogenic Hyphomycete ◽  
Spontaneous Mutants ◽  
Selection Of

Enhancement of virulence in entomogenous fungi has been a particularly neglected area of research (Roberts and Yendol 1971). It is generally believed that virulence increases following successive passage through a host and decreases following repeated subculturing on artificial media (see Aizawa 1971; Roberts and Yendol 1971). Using single-spore isolates (clones) of Beauveria bassiana (Bals.) Vuill., SamšiňSáková and Kálalová (1983) demonstrated spontaneous mutants with increased virulence. Enhancement of virulence using parasitic selection pressures has been accomplished by passage of fungal strains through a host (Daoust and Roberts 1982; references in Ignoffo et al. 1982). Such changes are thought to be due to gradual selection of genotypes.

Adaptation of the toxic freshwater cyanobacterium Microcystis aeruginosa to salinity is achieved by the selection of spontaneous mutants

2019 ◽  
Vol 67 (3) ◽  
pp. 192-201 ◽  
Author(s):  
Ignacio José Melero‐Jiménez ◽  
Elena Martín‐Clemente ◽  
María Jesús García‐Sánchez ◽  
Antonio Flores‐Moya ◽  
Elena Bañares‐España
Keyword(s):  
Microcystis Aeruginosa ◽  
Freshwater Cyanobacterium ◽  
Spontaneous Mutants ◽  
Selection Of

Selection of spontaneous mutants ofYarrowia lipolytica by inositol-less death

1989 ◽  
Vol 4 (6) ◽  
pp. 435-440 ◽  
Author(s):  
Ramunas Bigelis ◽  
Kathleen A. Black
Keyword(s):  
Spontaneous Mutants ◽  
Selection Of

Cognitive gadgets and cognitive priors

2019 ◽  
Vol 42 ◽  
Author(s):  
Gian Domenico Iannetti ◽  
Giorgio Vallortigara
Keyword(s):  
Cognitive Neuroscience ◽  
Selection Of

Abstract Some of the foundations of Heyes’ radical reasoning seem to be based on a fractional selection of available evidence. Using an ethological perspective, we argue against Heyes’ rapid dismissal of innate cognitive instincts. Heyes’ use of fMRI studies of literacy to claim that culture assembles pieces of mental technology seems an example of incorrect reverse inferences and overlap theories pervasive in cognitive neuroscience.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

Measurements of the Cape Astrometric Survey of the Southern Hemisphere

1978 ◽  
Vol 48 ◽  
pp. 515-521
Author(s):  
W. Nicholson
Keyword(s):  
Southern Hemisphere ◽  
Automatic Measuring ◽  
Measuring Machine ◽  
Final Selection ◽  
Selection Of

SummaryA routine has been developed for the processing of the 5820 plates of the survey. The plates are measured on the automatic measuring machine, GALAXY, and the measures are subsequently processed by computer, to edit and then refer them to the SAO catalogue. A start has been made on measuring the plates, but the final selection of stars to be made is still a matter for discussion.

Application of Improved Voltage Compensation in the SEM to Imaging of Organic Materials

1973 ◽  
Vol 31 ◽  
pp. 444-445
Author(s):  
P.J. Killingworth ◽  
M. Warren
Keyword(s):  
Electron Beam ◽  
Organic Materials ◽  
Operating Parameters ◽  
Low Density ◽  
Beam Diameter ◽  
Incident Electron Beam ◽  
Specimen Material ◽  
Voltage Compensation ◽  
Selection Of ◽  
Scanning Electron

Ultimate resolution in the scanning electron microscope is determined not only by the diameter of the incident electron beam, but by interaction of that beam with the specimen material. Generally, while minimum beam diameter diminishes with increasing voltage, due to the reduced effect of aberration component and magnetic interference, the excited volume within the sample increases with electron energy. Thus, for any given material and imaging signal, there is an optimum volt age to achieve best resolution.In the case of organic materials, which are in general of low density and electric ally non-conducting; and may in addition be susceptible to radiation and heat damage, the selection of correct operating parameters is extremely critical and is achiev ed by interative adjustment.

Selection and Preparation of Specific Tissue Regions For Tem Using Large Epoxy-Embedded Blocks

1973 ◽  
Vol 31 ◽  
pp. 324-325 ◽  
Author(s):  
P. M. Lowrie ◽  
W. S. Tyler
Keyword(s):  
Electron Microscopy ◽  
Anatomical Structures ◽  
Ultrastructural Studies ◽  
Transmission Electron ◽  
Microscopic Evaluation ◽  
Embedded Blocks ◽  
Specific Tissue ◽  
Definition Of ◽  
Areas Of Interest ◽  
Selection Of

The importance of examining stained 1 to 2μ plastic sections by light microscopy has long been recognized, both for increased definition of many histologic features and for selection of specimen samples to be used in ultrastructural studies. Selection of specimens with specific orien ation relative to anatomical structures becomes of critical importance in ultrastructural investigations of organs such as the lung. The uantity of blocks necessary to locate special areas of interest by random sampling is large, however, and the method is lacking in precision. Several methods have been described for selection of specific areas for electron microscopy using light microscopic evaluation of paraffin, epoxy-infiltrated, or epoxy-embedded large blocks from which thick sections were cut. Selected areas from these thick sections were subsequently removed and re-embedded or attached to blank precasted blocks and resectioned for transmission electron microscopy (TEM).

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