scholarly journals A Thiamine-Requiring Mutant of The Tomato

1961 ◽  
Vol 14 (1) ◽  
pp. 66 ◽  
Author(s):  
J Langridge ◽  
RD Brock
Keyword(s):  
Single Gene ◽  
Pyrimidine Ring ◽  
Specific Reaction ◽  
Gene Mutant

A spontaneous, single-gene mutant of the tomato is shown to be unable to synthesize thiamine. The specific reaction lost is either the methylation of position 2 or the activation of position 5 of the pyrimidine ring.

Ontogenetic study of the fusion of floral organs in the normal and "solanifolia" mutant of tomato (Lycopersicon esculentum)

1987 ◽  
Vol 65 (2) ◽  
pp. 215-221 ◽  
Author(s):  
K. N. Chandra Sekhar ◽  
V. K. Sawhney
Keyword(s):  
Lycopersicon Esculentum ◽  
Single Gene ◽  
Corolla Tube ◽  
Lateral Growth ◽  
Floral Organs ◽  
Lack Of Fusion ◽  
Organ Type ◽  
Gene Mutant ◽  
Ontogenetic Study ◽  
Single Ovary

A comparative study on the ontogeny of the fusion of floral organs of the normal (cv. Pearson) and a single-gene mutant, "solanifolia" (sf/sf), of tomato (Lycopersicon esculentum Mill.) was conducted. In the normal, floral organs were laterally fused, although the degree and the region of fusion varied in each organ type. In the mutant, the various organs either did not fuse or, if they did, were individually recognizable. The sepals and petals of mutant flowers, unlike those of the normal, did not form a calyx cup and a corolla tube, respectively, and this was related to the limited lateral growth of mutant primordia and the absence of growth in the interprimordial region. Also, petal primordia of the mutant were narrower in width at inception. The stamens of normal flowers were fused by interweaving rows of lateral and adaxial hairs on the anthers. The mutant stamens produced lateral and adaxial hairs, yet they were free. The nonfusion of mutant stamens was related to the smaller primordium widths, greater distance between the primordia, and the larger apex diameter at the time of stamen initiation. The gynoecium of normal flowers consisted of a single ovary, style, and stigma formed by the fusion of carpel primordia. In the mutant, the gynoecium consisted of several carpels, laterally adhered to each other, and each had a recognizable style and stigma. The lack of fusion of mutant carpels was attributed to the larger apex diameter of the mutant during carpel initiation.

scholarly journals Phenotypic analysis of catastrophic childhood epilepsy genes: The Epilepsy Zebrafish Project

2021 ◽  
Author(s):  
Aliesha Griffin ◽  
Colleen Carpenter ◽  
Jing Liu ◽  
Rosalia Paterno ◽  
Brian Grone ◽  
...  
Keyword(s):  
Neurological Disorders ◽  
Classification Scheme ◽  
Single Gene ◽  
Field Potential ◽  
Phenotypic Analysis ◽  
Electrographic Seizure ◽  
Starting Point ◽  
Gene Mutant ◽  
Epilepsy Classification ◽  
Neuroscience Community

AbstractGenetic engineering techniques have contributed to the now widespread use of zebrafish to investigate gene function, but zebrafish-based human disease studies, and particularly for neurological disorders, are limited. Here we used CRISPR-Cas9 to generate 40 single-gene mutant zebrafish lines representing catastrophic childhood epilepsies. We evaluated larval phenotypes using electrophysiological, behavioral, neuro-anatomical, survival and pharmacological assays. Phenotypes with unprovoked electrographic seizure activity (i.e., epilepsy) were identified in zebrafish lines for 8 genes; ARX, EEF1A, GABRB3, GRIN1, PNPO, SCN1A, STRADA and STXBP1. A unifying epilepsy classification scheme was developed based on local field potential recordings and blinded scoring from ~3300 larvae. We also created an open-source database containing sequencing information, survival curves, behavioral profiles and representative electrophysiology data. We offer all zebrafish lines as a resource to the neuroscience community and envision them as a starting point for further functional analysis and/or identification of new therapies.

scholarly journals Phenotypic analysis of catastrophic childhood epilepsy genes

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Aliesha Griffin ◽  
Colleen Carpenter ◽  
Jing Liu ◽  
Rosalia Paterno ◽  
Brian Grone ◽  
...  
Keyword(s):  
Neurological Disorders ◽  
Seizure Activity ◽  
Single Gene ◽  
Field Potential ◽  
Childhood Epilepsy ◽  
Phenotypic Analysis ◽  
Electrographic Seizure ◽  
Starting Point ◽  
Gene Mutant ◽  
Neuroscience Community

AbstractGenetic engineering techniques have contributed to the now widespread use of zebrafish to investigate gene function, but zebrafish-based human disease studies, and particularly for neurological disorders, are limited. Here we used CRISPR-Cas9 to generate 40 single-gene mutant zebrafish lines representing catastrophic childhood epilepsies. We evaluated larval phenotypes using electrophysiological, behavioral, neuro-anatomical, survival and pharmacological assays. Local field potential recordings (LFP) were used to screen ∼3300 larvae. Phenotypes with unprovoked electrographic seizure activity (i.e., epilepsy) were identified in zebrafish lines for 8 genes; ARX, EEF1A, GABRB3, GRIN1, PNPO, SCN1A, STRADA and STXBP1. We also created an open-source database containing sequencing information, survival curves, behavioral profiles and representative electrophysiology data. We offer all zebrafish lines as a resource to the neuroscience community and envision them as a starting point for further functional analysis and/or identification of new therapies.

Gld and Lpr Mice: Single Gene Mutant Models for Failed Self Tolerance

1994 ◽  
Vol 11 (3) ◽  
pp. 231-244 ◽  
Author(s):  
Avinash Bhandoola ◽  
Katsuyuki Yui ◽  
Richard M. Siegel ◽  
Loukia Zerva ◽  
Mark I. Greene
Keyword(s):  
Single Gene ◽  
Self Tolerance ◽  
Gene Mutant

THE ACTION OF A MODIFIER GENE ON THE PUFF MORPHOLOGICAL MUTANT OF SCHIZOPHYLLUM COMMUNE

1970 ◽  
Vol 12 (1) ◽  
pp. 70-79
Author(s):  
Philip G. Miles
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Single Gene ◽  
Schizophyllum Commune ◽  
Modifier Gene ◽  
Mutagenic Treatment ◽  
Wild Type ◽  
Great Utility ◽  
Gene Mutant ◽  
Lateral Branches

The puff mutant of Schizophyllum commune is characterized by bead-like puffs of hyphae formed by extensive dichotomous branching of lateral branches from main hyphae. Puff segregates as a single gene mutant when mated with wild-type although the expression of the puff phenotype is variable. A modifier gene of puff, p-mod-1, is described. Strains bearing the gene for puff (p) and the p-mod-1 gene are of wild-type appearance macroscopically, but can generally be distinguished microscopically by the dichotomous branching of the hyphal tips. The p-mod-1 gene segregates independently of p. The puff mutant is elasticotropic (i.e. grows along lines of stress), but the presence of the p-mod-1 gene removes this effect. The p-mod-1 gene arose spontaneously in a wild-type strain, but modifiers of mutant morphology have also been obtained by mutagenic treatment. Such modifiers have great utility in morphogenetic studies of hyphal development.

A ‘TEA+-insensitive’ mutant with increased potassium conductance in Paramecium aurelia

1976 ◽  
Vol 65 (1) ◽  
pp. 51-63
Author(s):  
Y. Satow ◽  
C. Kung
Keyword(s):  
Single Gene ◽  
Potassium Conductance ◽  
Input Resistance ◽  
Membrane Resistance ◽  
Type B ◽  
Wild Type ◽  
Zero Current ◽  
Gene Mutant ◽  
Current Input

A single-gene mutant of Paramecium aurelia is analysed electrophysiologically. (a) The regenerative Ca-response, triggered by small or moderate current, was smaller and slower in the mutant than in wild type. (b) Input resistance of the mutant membrane is about half of that of wild type bathed in various solutions. This is true for the zero-current input resistance and the chord resistance measured with high depolarizing current. (c) Membrane resistance of the mutant measure with hyperpolarizing currents is smaller than that of wild type only when K+ is the major external cation. (d) Internally applied TEA+ or externally applied Ba+ increases the membrane resistance of the mutant to that of wild type similarly treated. We conclude that the mutant has an increased K conductance.

scholarly journals Sex-determining genes in the homosporous fern Ceratopteris

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 1949-1958 ◽  
Author(s):  
J.A. Banks
Keyword(s):  
Sex Determination ◽  
Double Mutant ◽  
Single Gene ◽  
Regulatory Pathway ◽  
Male Development ◽  
Gene Mutant ◽  
Sex Type ◽  
Homosporous Fern ◽  
Mutant Phenotypes ◽  
Sporophyte Development

Haploid Ceratopteris gametophytes are either hermaphroditic or male. The determinate of sex type is the pheromone antheridiogen (ACE) which is secreted by the meristic hermaphrodite and promotes ameristic male development of sexually undetermined gametophytes. Several mutations effecting the sex of the haploid gametophyte have been isolated and are described. The hermaphroditic (her) mutants are insensitive to ACE and develop as meristic hermaphrodites. These mutations effect ameristic male development in the presence of ACE but have no effect on hermaphroditic development. While most her mutations also have no effect on diploid sporophyte development, some partially ACE-insensitive her mutations have profound effects on sporophyte development. The transformer (tra) mutation effects both meristem and archegonia formation and causes the gametophyte to be an ameristic male under conditions that promote hermaphroditic development. The feminization (fem) mutation effects antheridia development in both male and hermaphroditic gametophytes and causes the gametophyte to develop as a meristic female in the absence or presence of the pheromone. The her1 tra1 double mutant is male in the absence or presence of ACE, indicating that tra1 is epistatic to her1. The phenotypes of her1, tra1 and fem1 single gene mutant phenotypes and the her1 tra1 double mutant phenotype are used to deduce a model suggesting how the products of these genes might interact in a regulatory pathway to control sex determination.

scholarly journals Reversible control of synaptic transmission in a single gene mutant of Drosophila melanogaster.

1983 ◽  
Vol 96 (6) ◽  
pp. 1517-1522 ◽  
Author(s):  
J H Koenig ◽  
K Saito ◽  
K Ikeda
Keyword(s):  
Drosophila Melanogaster ◽  
Elevated Temperature ◽  
Synaptic Transmission ◽  
Transmitter Release ◽  
Flight Muscle ◽  
Single Gene ◽  
Gene Mutant ◽  
Excitatory Junction Potential ◽  
Excitatory Junction Potentials ◽  
Junction Potential

Synaptic transmission of the single gene mutant, shibirets1 (shi), of Drosophila melanogaster is reversibly blocked by elevated temperature. The presynaptic mechanism of transmission was studied in the neuromuscular junction of the dorsal longitudinal flight muscle of this mutant. It was observed that when the temperature was raised to 29 degrees C in shi flies, the amplitude of the excitatory junction potential (EJP) greatly diminished, the frequency of spontaneously released miniature excitatory junction potentials (MEJP's) was greatly reduced, and almost complete vesicle depletion was observed. These conditions were reversible if the temperature was lowered to 19 degrees C. These data suggest that the block in transmission is a result of vesicle depletion. It is suggested that depletion occurs not as a result of excessive release of transmitter but rather as a result of a block in the recycling of vesicles, which causes depletion as exocytosis (transmitter release) proceeds normally.

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