scholarly journals Ongoing Electroencephalographic Rhythms Related to Exploratory Movements in Transgenic TASTPM Mice

2020 ◽  
Vol 78 (1) ◽  
pp. 291-308 ◽  
Author(s):  
Claudio Del Percio ◽  
Wilhelmus Drinkenburg ◽  
Susanna Lopez ◽  
Maria Teresa Pascarelli ◽  
Roberta Lizio ◽  
...  
Keyword(s):  
Cognitive Deficits ◽  
Wild Type ◽  
Eeg Rhythms ◽  
Double Mutation ◽  
Passive Condition ◽  
Theta Frequency ◽  
Pros And Cons ◽  
Active Condition ◽  
Eeg Power ◽  
Exploratory Movements

Background: The European PharmaCog study (http://www.pharmacog.org) has reported a reduction in delta (1–6 Hz) electroencephalographic (EEG) power (density) during cage exploration (active condition) compared with quiet wakefulness (passive condition) in PDAPP mice (hAPP Indiana V717F mutation) modeling Alzheimer’s disease (AD) amyloidosis and cognitive deficits. Objective: Here, we tested the reproducibility of that evidence in TASTPM mice (double mutation in APP KM670/671NL and PSEN1 M146V), which develop brain amyloidosis and cognitive deficits over aging. The reliability of that evidence was examined in four research centers of the PharmaCog study. Methods: Ongoing EEG rhythms were recorded from a frontoparietal bipolar channel in 29 TASTPM and 58 matched “wild type” C57 mice (range of age: 12–24 months). Normalized EEG power was calculated. Frequency and amplitude of individual delta and theta frequency (IDF and ITF) peaks were considered during the passive and active conditions. Results: Compared with the “wild type” group, the TASTPM group showed a significantly lower reduction in IDF power during the active over the passive condition (p < 0.05). This effect was observed in 3 out of 4 EEG recording units. Conclusion: TASTPM mice were characterized by “poor reactivity” of delta EEG rhythms during the cage exploration in line with previous evidence in PDAPP mice. The reliability of that result across the centers was moderate, thus unveiling pros and cons of multicenter preclinical EEG trials in TASTPM mice useful for planning future studies.

Ongoing Electroencephalographic Activity Associated with Cortical Arousal in Transgenic PDAPP Mice (hAPP V717F)

2018 ◽  
Vol 15 (3) ◽  
pp. 259-272 ◽  
Author(s):  
Claudio Del Percio ◽  
Wilhelmus Drinkenburg ◽  
Susanna Lopez ◽  
Cristina Limatola ◽  
Jesper F. Bastlund ◽  
...  
Keyword(s):  
Active State ◽  
Passive State ◽  
Large Animal ◽  
Cortical Arousal ◽  
Eeg Rhythms ◽  
Passive Condition ◽  
Disease Modifying Drugs ◽  
Theta Frequency ◽  
Neural Transmission ◽  
Electroencephalographic Activity

Background: It has been shown that theta (6-10 Hz) and delta (1-6 Hz) ongoing electroencephalographic (EEG) rhythms revealed variations in the cortical arousal in C57 Wild Type (WT) mice during cage exploration (active condition) compared to awake quiet behavior (passive condition; IMI PharmaCog project, www.pharmacog.eu). Objective: The objective was to test if these EEG rhythms might be abnormal in old PDAPP mice modeling Alzheimer's disease (AD) with a hAPP Indiana V717F mutation (They show abnormal neural transmission, cognitive deficits, and brain accumulation of Aβ1-42). Methods: Ongoing EEG rhythms were recorded by a frontoparietal bipolar channel in 15 PDAPP and 23 WT C57 male mice (mean age of 22.8 months ±0.4 and 0.3 standard error, respectively). EEG absolute power (density) was calculated. Frequency and amplitude of individual delta and theta frequency (IDF and ITF) peaks were considered during passive and active states in the wakefulness. Results: Compared with the WT group, the PDAPP group showed higher frequency of the IDF during the passive condition and lower frequency of the ITF during the active state. Furthermore, the WT but not PDAPP group showed significant changes in the frontoparietal EEG power (IDF, ITF) during active over passive state. Conclusion: PDAPP mice were characterized by less changes in the brain arousal during an active state as revealed by frontoparietal EEG rhythms. Future studies will have to cross-validate the present results on large animal groups, clarify the neurophysiological underpinning of the effect, and test if the disease modifying drugs against AD amyloidosis normalize those candiate EEG biomarkers in PDAPP mice

scholarly journals CRISPR knockouts of pmela and pmelb engineered a golden tilapia by regulating relative pigment cell abundance

2021 ◽  
Author(s):  
Chenxu Wang ◽  
Jia Xu ◽  
Thomas D. Kocher ◽  
Minghui Li ◽  
Deshou Wang
Keyword(s):  
Pigment Cell ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Homozygous Mutation ◽  
Body Color ◽  
Wild Type ◽  
Double Mutation ◽  
Vertical Bars ◽  
White Plumage ◽  
New Strategies

Premelanosome protein (pmel) is a key gene for melanogenesis in vertebrates. Mutations in this gene are responsible for white plumage in chicken, but its role in pigmentation of fish remains to be demonstrated. In this study we found that most fishes have two pmel genes arising from the teleost-specific whole genome duplication. Both pmela and pmelb were expressed at high levels in the eyes and skin of Nile tilapia. We mutated both genes in tilapia using CRISPR/Cas9 gene editing. Homozygous mutation of pmela resulted in yellowish body color with weak vertical bars and a hypo-pigmented retinal pigment epithelium (RPE) due to significantly reduced number and size of melanophores. In contrast, we observed an increased number and size of xanthophores in mutants compared to wild-type fish. Homozygous mutation of pmelb resulted in a similar, but milder phenotype than pmela -/- mutants, without effects on RPE pigmentation. Double mutation of pmela and pmelb resulted in loss of additional melanophores compared to the pmela -/- mutants, and also an increase in the number and size of xanthophores, producing a strong golden body color without bars in the trunk. The RPE pigmentation of pmela -/ - ;pmelb -/- was similar to pmela -/- mutants, with much less pigmentation than pmelb -/- mutants and wild-type fish. Taken together, our results indicate that, while both pmel genes are important for the formation of body color in tilapia, pmela plays a more important role than pmelb. To our knowledge, this is the first report on mutation of pmelb or both pmela;pmelb in fish. Studies on these mutants suggest new strategies for breeding golden tilapia, and also provide a new model for studies of pmel function in vertebrates.

scholarly journals Mutant Firefly Luciferase Enzymes Resistant to the Inhibition by Sodium Chloride

2021 ◽  
Author(s):  
Satoshi Yawata ◽  
Kenichi Noda ◽  
Ai Shimomura ◽  
Akio Kuroda
Keyword(s):  
Sodium Chloride ◽  
Double Mutant ◽  
Luciferase Activity ◽  
Firefly Luciferase ◽  
Activity Level ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Wild Type ◽  
Original Activity ◽  
Double Mutation

Abstract ObjectivesFirefly luciferase, one of the most extensively studied enzymes, has numerous applications. However, luciferase activity is inhibited by sodium chloride. This study aims to expand the applications of firefly luciferase in the presence of sodium chloride.ResultsWe first obtained two mutant luciferase enzymes whose inhibition were alleviated and identified these mutations as Val288Ile and Glu488Val. Under dialysis condition (140 mM sodium chloride), the wild type was inhibited to 44% of its original activity level. In contrast, the single mutants, Val288Ile and Glu488Val, retained 67% and 79% of their original activity, respectively. Next, we introduced Val288Ile and Glu488Val mutations into the wild-type luciferase to create a double mutant using site-directed mutagenesis. Notably, the double mutant retained its activity more than 95% of that in the absence of sodium chloride.ConclusionsThe mutant luciferase, named luciferase CR, was found to retain its activity in various concentrations of sodium chloride. The inhibition of luciferase CR under dialysis condition was more alleviated than either Val288Ile or Glu488Val alone, suggesting that the effect of the double mutation was cumulative. We discussed the effect of mutations on the alleviation of the inhibition by sodium chloride.

Multiple GCD genes required for repression of GCN4, a transcriptional activator of amino acid biosynthetic genes in Saccharomyces cerevisiae

1986 ◽  
Vol 6 (11) ◽  
pp. 3990-3998
Author(s):  
S Harashima ◽  
A G Hinnebusch
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Lacz Gene ◽  
Gene Products ◽  
Wild Type ◽  
Double Mutation ◽  
Double Stranded Rna ◽  
Amino Acid Availability ◽  
Genes Encoding ◽  
New Alleles

GCN4 encodes a positive regulator of multiple unlinked genes encoding amino acid biosynthetic enzymes in Saccharomyces cerevisiae. Expression of GCN4 is coupled to amino acid availability by a control mechanism involving GCD1 as a negative effector and GCN1, GCN2, and GCN3 as positive effectors of GCN4 expression. We used reversion of a gcn2 gcn3 double mutation to isolate new alleles of GCD1 and mutations in four additional GCD genes which we designate GCD10, GCD11, GCD12, and GCD13. All of the mutations lead to constitutive derepression of HIS4 transcription in the absence of the GCN2+ and GCN3+ alleles. By contrast, the gcd mutations require the wild-type GCN4 allele for their derepressing effect, suggesting that each acts by influencing the level of GCN4 activity in the cell. Consistent with this interpretation, mutations in each GCD gene lead to constitutive derepression of a GCN4::lacZ gene fusion. Thus, at least five gene products are required to maintain the normal repressed level of GCN4 expression in nonstarvation conditions. Interestingly, the gcd mutations are pleiotropic and also affect growth rate in nonstarvation conditions. In addition, certain alleles lead to a loss of M double-stranded RNA required for the killer phenotype. This pleiotropy suggests that the GCD gene products contribute to an essential cellular function, in addition to, or in conjunction with, their role in GCN4 regulation.

Entropic effect and residue specific entropic contribution to the cooperativity in streptavidin–biotin binding

Nanoscale ◽  
2020 ◽  
Vol 12 (13) ◽  
pp. 7134-7145 ◽  
Author(s):  
Yalong Cong ◽  
Kaifang Huang ◽  
Yuchen Li ◽  
Susu Zhong ◽  
John Z. H. Zhang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Md Simulations ◽  
Specific Charge ◽  
Wild Type ◽  
Double Mutation ◽  
Biotin Binding ◽  
Entropic Effect ◽  
Entropic Contribution

Molecular dynamics (MD) simulations were performed employing the polarized protein-specific charge (PPC) to explore the origin of the cooperativity in streptavidin–biotin systems (wild type, two single mutations and one double-mutation).

Human Finger Independence: Limitations due to Passive Mechanical Coupling Versus Active Neuromuscular Control

2004 ◽  
Vol 92 (5) ◽  
pp. 2802-2810 ◽  
Author(s):  
Catherine E. Lang ◽  
Marc H. Schieber
Keyword(s):  
Neuromuscular Control ◽  
The Other ◽  
Passive Condition ◽  
Mechanical Coupling ◽  
Complete Independence ◽  
Active Condition ◽  
Middle Ring ◽  
Human Finger ◽  
Passive Movements ◽  
Flexion And Extension

We studied the extent to which mechanical coupling and neuromuscular control limit finger independence by studying passive and active individuated finger movements in healthy adults. For passive movements, subjects relaxed while each finger was rotated into flexion and extension by a custom-built device. For active movements, subjects moved each finger into flexion and extension while attempting to keep the other, noninstructed fingers still. Active movements were performed through approximately the same joint excursions and at approximately the same speeds as the passive movements. We quantified how mechanical coupling limited finger independence from the passive movements, and quantified how neuromuscular control limited finger independence using an analysis that subtracted the indices obtained in the passive condition from those obtained in the active condition. Finger independence was generally similar during passive and active movements, but showed a trend toward less independence in the middle, ring, and little fingers during active, large-arc movements. Mechanical coupling limited the independence of the index, middle, and ring fingers to the greatest degree, followed by the little finger, and placed only negligible limitations on the independence of the thumb. In contrast, neuromuscular control primarily limited the independence of the ring, and little fingers during large-arc movements, and had minimal effects on the other fingers, especially during small-arc movements. For the movement conditions tested here, mechanical coupling between the fingers appears to be a major factor limiting the complete independence of finger movement.

scholarly journals 11 Study of Polynucleotide Kinase/Phosphatase (PNKP) Mutations Found in a Patient with Microcephaly, Seizures, and Developmental Delay (MCSZ) and Glioblastoma

2018 ◽  
Vol 45 (S3) ◽  
pp. S2-S2
Author(s):  
Bingcheng Jiang ◽  
Chibawanye I. Ene ◽  
Bonnie Cole ◽  
Jeff Ojemann ◽  
Sarah Leary ◽  
...  
Keyword(s):  
Human Cancer ◽  
Neurodevelopmental Disorder ◽  
Site Directed Mutagenesis ◽  
Expression Vectors ◽  
Wild Type ◽  
Double Mutation ◽  
Mutant Proteins ◽  
Human Cancer Cell Lines ◽  
Mammalian Expression ◽  
Polynucleotide Kinase

The enzyme polynucleotide kinase/phosphatase (PNKP) plays a key role in DNA repair by resolving the chemistry at DNA strand breaks. Mutations in PNKP (chromosome 19q13.4) are known to cause MCSZ, a serious neurodevelopmental disorder, but to date there has been no link to cancer initiation or progression. However, a child with MCSZ recently presented at Seattle Children's Hospital with a 3-cm glioblastoma. The child was shown to have two germline mutations in PNKP. To study the effects of the PNKP mutations found in this patient, we generated mutant PNKP cDNAs carrying either the individual mutations or the double mutation using site directed mutagenesis. These cDNAs were incorporated into bacterial and mammalian expression vectors. The bacterially expressed mutant proteins as well as the wild type have been purified and are undergoing testing for PNKP DNA kinase and phosphatase activity. The PNKP cDNAs, fused to GFP, were expressed in Hela and HCT116 human cancer cell lines. High-content analysis and micro-irradiation techniques are being used to determine PNKP localization within the cells and recruitment to damaged DNA. Our preliminary results indicate that the mutations alter the ratio of nuclear to cytoplasmic PNKP compared to the wild-type protein.

scholarly journals Sex-specific hippocampus-dependent cognitive deficits and increased neuronal autophagy in DEspR haploinsufficiency in mice

2008 ◽  
Vol 35 (3) ◽  
pp. 316-329 ◽  
Author(s):  
Victoria L. M. Herrera ◽  
Julius L. Decano ◽  
Pia Bagamasbad ◽  
Timothy Kufahl ◽  
Martin Steffen ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Cognitive Performance ◽  
Cognitive Deficits ◽  
Mammalian Target Of Rapamycin ◽  
Male Mice ◽  
Wild Type ◽  
Neuronal Homeostasis ◽  
Subcortical Regions ◽  
Neuronal Autophagy ◽  
Neuronal Vacuolation

Aside from abnormal angiogenesis, dual endothelin-1/VEGF signal peptide-activated receptor deficiency ( DEspR−/−) results in aberrant neuroepithelium and neural tube differentiation, thus elucidating DEspR's role in neurogenesis. With the emerging importance of neurogenesis in adulthood, we tested the hypothesis that nonembryonic-lethal DEspR haploinsufficiency ( DEspR+/−) perturbs neuronal homeostasis, thereby facilitating aging-associated neurodegeneration. Here we show that, in male mice only, DEspR-haploinsufficiency impaired hippocampus-dependent visuospatial and associative learning and induced noninflammatory spongiform changes, neuronal vacuolation, and loss in the hippocampus, cerebral cortex, and subcortical regions, consistent with autophagic cell death. In contrast, DEspR+/− females exhibited better cognitive performance than wild-type females and showed absence of neuropathological changes. Signaling pathway analysis revealed DEspR-mediated phosphorylation of activators of autophagy inhibitor mammalian target of rapamycin (mTOR) and dephosphorylation of known autophagy inducers. Altogether, the data demonstrate DEspR-mediated diametrical, sex-specific modulation of cognitive performance and autophagy, highlight cerebral neuronal vulnerability to autophagic dysregulation, and causally link DEspR haploinsufficiency with increased neuronal autophagy, spongiosis, and cognitive decline in mice.

Development of Active and Passive Fatigue Manipulations Using a Driving Simulator

2007 ◽  
Vol 51 (18) ◽  
pp. 1237-1241 ◽  
Author(s):  
Dyani J. Saxby ◽  
Gerald Matthews ◽  
Edward M. Hitchcock ◽  
Joel S. Warm
Keyword(s):  
Time Course ◽  
Passive Control ◽  
Driving Simulator ◽  
Negative Mood ◽  
Subjective Response ◽  
Passive Condition ◽  
Full Control ◽  
Active Condition ◽  
The Impact ◽  
Simulated Wind

The present study investigates driving simulator methodologies for inducing qualitatively different patterns of subjective response. The study tested Desmond and Hancock's (2001) theory that there may be two types of fatigue: active and passive. 108 undergraduates participated. There were 3 conditions (active, passive, control) and 3 durations (10, 30, 50 minutes). The active condition used simulated wind gusts to increase the required number of steering and acceleration changes. The passive condition was fully automated. In the control condition, drivers were in full control of steering and acceleration. Task engagement (e.g., energy) was lowest in the passive fatigue condition, followed by the control and active conditions. Distress (e.g., negative mood) was found to be highest in the active fatigue condition. The time course of fatigue responses was also determined. The results suggest methods for developing manipulations to determine the impact of fatigue on performance.

Different Sensitivities of Mutants and Chimeric Forms of Human Muscle and Liver Fructose- 1,6-Bisphosphatases towards AMP

2003 ◽  
Vol 384 (1) ◽  
pp. 51-58 ◽  
Author(s):  
D. Rakus ◽  
H. Tillmann ◽  
R. Wysocki ◽  
S. Ulaszewski ◽  
K. Eschrich ◽  
...  
Keyword(s):  
Liver Enzyme ◽  
Human Liver ◽  
Human Muscle ◽  
Wild Type ◽  
Muscle Enzyme ◽  
Double Mutation ◽  
Binding Domains ◽  
Fructose 1,6 Bisphosphatase ◽  
Amp Inhibition ◽  
Acid Exchange

Abstract AMP is an allosteric inhibitor of human muscle and liver fructose-1,6-bisphosphatase (FBPase). Despite strong similarity of the nucleotide binding domains, the muscle enzyme is inhibited by AMP approximately 35 times stronger than liver FBPase: I0.5 for muscle and for liver FBPase are 0.14 uM and 4.8 uM, respectively. Chimeric human muscle (L50M288) and chimeric human liver enzymes (M50L288), in which the N-terminal residues (1-50) were derived from the human liver and human muscle FBPases, respectively, were inhibited by AMP 2-3 times stronger than the wild-type liver enzyme. An amino acid exchange within the Nterminal region of the muscle enzyme towards liver FBPase (Lys20→Glu) resulted in 13-fold increased I0.5 values compared to the wild-type muscle enzyme. However, the opposite exchanges in the liver enzyme (Glu20→Lys and double mutation Glu19→Asp/Glu20→Lys) did not change the sensitivity for AMP inhibition of the liver mutant (I0.5 value of 4.9 uM). The decrease of sensitivity for AMP of the muscle mutant Lys20→Glu, as well as the lack of changes in the inhibition by AMP of liver mutants Glu20→Lys and Glu19→Asp/Glu20→Lys, suggest a different mechanism of AMP binding to the muscle and liver enzyme.

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