A PRELIMINARY STUDY OF THE CAROTENOIDS IN ACRASIS ROSEA

1966 ◽  
Vol 44 (3) ◽  
pp. 269-274 ◽  
Author(s):  
Melvin S. Fuller ◽  
Rachel M. Rakatansky
Keyword(s):  
Rhodotorula Mucilaginosa ◽  
Wild Type ◽  
Preliminary Study ◽  
White Mutant

The amoebae of Acrasis rosea grown on a white mutant of Rhodotorula mucilaginosa contained three colored carotenoids. Two of these were xanthophylls, one being torulene with absorption maxima in hexane at 458, 484, and 518 mμ. The second xanthophyll, the most abundant pigment of the amoebae, was an unknown carotenoid with absorption maxima in hexane at 453, 477, and 508 mμ. A carotene with absorption maxima in hexane at 442, 468, and 500 mμ was also present in small amounts but not identified with any known carotene.It was demonstrated, contrary to a previous report, that the amoebae of A. rosea multiplied and became pigmented on carotenoid-lacking yeasts such as Saccharomyces cereviseae. On such colorless yeasts, the pigments were qualitatively the same as those isolated when A. rosea was grown on the colored wild-type and white mutant of R. mucilaginosa. The synthesis of torulene must then be accomplished, at least in its final stages, by the amoebae of A. rosea.

Inhibition of toxicity and protofibril formation in the amyloid-β peptide β(25–35) using N-Methylated derivatives

2002 ◽  
Vol 30 (4) ◽  
pp. 537-542 ◽  
Author(s):  
A. J. Doig ◽  
E. Hughes ◽  
R. M. Burke ◽  
T. J. Su ◽  
R. K. Heenan ◽  
...  
Keyword(s):  
Amyloid Β ◽  
Outer Edge ◽  
Amyloid Β Peptide ◽  
Wild Type ◽  
Diphenyltetrazolium Bromide ◽  
Amyloidogenic Peptides ◽  
Β Amyloid ◽  
Preliminary Study ◽  
Fibril Morphology ◽  
Derivatives Of

β(25–35) is a fragment of β-amyloid that retains its wild-type properties. N-methylated derivatives of β(25–35) can block hydrogen bonding on the outer edge of the assembling amyloid, so preventing the aggregation and inhibiting the toxicity of the wild-type peptide. The effects are assayed by Congo Red and thioflavin T binding, electron microscopy and an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] toxicity assay. N-methyl-Gly-25 has similar properties to the wild-type, while five other methylation sites have varying effects on prefolded fibrils and fibril assembly. In particular, N-methyl-Gly-33 is able to completely prevent fibril assembly and reduces the toxicity of prefolded amyloid. With N-methyl-Leu-34 the fibril morphology is altered and toxicity reduced. A preliminary study of β(25–35) structure in aqueous solution was made by small-angle neutron scattering (SANS). The protofibrillar aggregates are best described as a disc of radius 140 å and height 53 å (1 å = 0.1 nm), though the possibility of polydisperse aggregates cannot be ruled out. No aggregates form in the presence of N-methyl-Gly-33. We suggest that the use of N-methylated derivatives of amyloidogenic peptides and proteins could provide a general solution to the problem of amyloid deposition and toxicity and that SANS is an important technique for the direct observation of protofibril formation and destruction in solution.

scholarly journals Electrophysiological features of sleep in children with Kir4.1 channel mutations and Autism–Epilepsy phenotype: a preliminary study

SLEEP ◽  
2019 ◽  
Vol 43 (4) ◽  
Author(s):  
Federico Cucchiara ◽  
Paolo Frumento ◽  
Tommaso Banfi ◽  
Gianluca Sesso ◽  
Marco Di Galante ◽  
...  
Keyword(s):  
Case Control Study ◽  
Preliminary Finding ◽  
Autism Spectrum ◽  
Case Control ◽  
Clinical Applications ◽  
Slow Waves ◽  
Wild Type ◽  
Children With Asd ◽  
Preliminary Study ◽  
Control Study

Abstract Study Objectives Recently, a role for gain-of-function (GoF) mutations of the astrocytic potassium channel Kir4.1 (KCNJ10 gene) has been proposed in subjects with Autism–Epilepsy phenotype (AEP). Epilepsy and autism spectrum disorder (ASD) are common and complexly related to sleep disorders. We tested whether well characterized mutations in KCNJ10 could result in specific sleep electrophysiological features, paving the way to the discovery of a potentially relevant biomarker for Kir4.1-related disorders. Methods For this case–control study, we recruited seven children with ASD either comorbid or not with epilepsy and/or EEG paroxysmal abnormalities (AEP) carrying GoF mutations of KCNJ10 and seven children with similar phenotypes but wild-type for the same gene, comparing period-amplitude features of slow waves detected by fronto-central bipolar EEG derivations (F3-C3, F4-C4, and Fz-Cz) during daytime naps. Results Children with Kir4.1 mutations displayed longer slow waves periods than controls, in Fz-Cz (mean period = 112,617 ms ± SE = 0.465 in mutated versus mean period = 105,249 ms ± SE = 0.375 in controls, p < 0.001). An analog result was found in F3-C3 (mean period = 125,706 ms ± SE = 0.397 in mutated versus mean period = 120,872 ms ± SE = 0.472 in controls, p < 0.001) and F4-C4 (mean period = 127,914 ms ± SE = 0.557 in mutated versus mean period = 118,174 ms ± SE = 0.442 in controls, p < 0.001). Conclusion This preliminary finding suggests that period-amplitude slow wave features are modified in subjects carrying Kir4.1 GoF mutations. Potential clinical applications of this finding are discussed.

The Role of Carotenoid Pigments in Cr(VI) Tolerance, Biosorption and Bioaccumulation by Rhodotorula mucilaginosa UCM Y-1776 and its Mutants

2007 ◽  
Vol 20-21 ◽  
pp. 611-614 ◽  
Author(s):  
Olag G. Mameeva ◽  
T.P. Kasatkina ◽  
V.S. Podgorsky
Keyword(s):  
Wild Strain ◽  
Protective Role ◽  
Rhodotorula Mucilaginosa ◽  
Chromium Toxicity ◽  
Living Biomass ◽  
Sorption Ability ◽  
White Mutant ◽  
Chromium Uptake ◽  
Significant Growth Inhibition

To compare Cr (VI) tolerance, biosorption and bioaccumulation for initial carotenoidsproducing yeast Rhodotorula mucilaginosa UCM Y-1776 and its mutants, twenty stable mutants with various intensity of colors were obtained using nitrosoguanidine (NSG). The ultraviolet was found to be inefficient as a mutagen in our study. Light- and non-pigmented mutants (4L and 2) demonstrated a significant growth inhibition by 30 mg/l Cr (VI) whereas wild strain was able to grow at much higher chromium concentrations (500 mg/l). Cr (VI) sorption ability of R. mucilaginosa UCM Y-1776 was higher than those of mutants. Cr (VI) sorption/uptake parameters (Qmax, b) were found to be close for initial pink-pigmented R. mucilaginosa UCM Y-1776 (Qmax = 950 5M/g), and its light-pigmented mutant 4L (Qmax = 678 5M/g) and non-pigmented mutant 2 (Qmax = 790 5M/g) by non-living biomass. Non-pigmented “white” mutant 2 showed the highest ability to sorb chromium ions by living biomass (Qmax = 1020 mmol/g). The least chromiumtolerant light-pigmented (mutant 4L) and non-pigmented yeasts showed the highest chromium uptake for living biomass. The results showed that the presence of carotenoids did not affect Cr (VI) ions sorption by yeast biomass which could highlight significance of chitin and glucan-mannoprotein complex in chromium biosorption. However pigment absence increased Cr (VI) bioaccumulation by living yeast demonstrating the protective role of carotenoids against hexavalent chromium toxicity.

A white mutant of Malay apple fruit (Syzygium malaccense) lacks transcript expression and activity for the last enzyme of anthocyanin synthesis, and the normal expression of a MYB transcription factor

2011 ◽  
Vol 38 (1) ◽  
pp. 75 ◽  
Author(s):  
Panumas Kotepong ◽  
Saichol Ketsa ◽  
Wouter G. van Doorn
Keyword(s):  
Transcription Factor ◽  
Myb Transcription Factor ◽  
Anthocyanin Synthesis ◽  
Wild Type ◽  
Fruit Maturation ◽  
Total Anthocyanin ◽  
White Skin ◽  
Fruit Skin ◽  
In The Wild ◽  
White Mutant

The fruit skin of the mature Malay apple (Syzygium malaccense (L.) Merr. & L.M. Perry) is initially glossy red, then changes to purple. A mutant having mature fruits with white skin has been identified. The skin of wild-type fruit contained five glucose-based anthocyanins (cyanidin-3-O-glucoside, pelargonidin-3-O-glucoside, peonidin-3-O-glucoside, cyanidin-3,5-O-diglucoside and peonidin-3,5-O-diglucoside). Cyanidin-3-O-glucoside accounted for a large proportion of the total anthocyanin content. The accumulation cyanidin-3-O-glucoside during fruit maturation was correlated with increased activities of phenylalanine ammonia lyase (PAL) and UDPglucose : flavonoid 3-O-glucosyltransferase (UF3GlucT, F3GT). In the wild-type fruit skin, transcripts of seven genes that encode enzymes in the anthocyanin biosynthetic pathway were detected. No anthocyanins were found in the white mutant fruit skin. The skin of the white mutant fruit contained transcripts of all seven genes identified, except F3GT. It also showed no F3GT activity. The data indicate that the lack of anthocyanins in the mutant is due to lack of F3GT expression. In addition, the transcript of a MYB transcription factor, highly homologous to three Arabidopsis MYBs involved in anthocyanin synthesis, was virtually absent in the mutant but very high in the wild-type fruit. It is suggested that the lack of MYB expression is part of the cause of the lack of F3GT expression and anthocyanin synthesis during fruit maturation.

Dormancy in white-grain mutants of Chinese Spring wheat (Triticum aestivum L.)

2000 ◽  
Vol 10 (1) ◽  
pp. 51-60 ◽  
Author(s):  
R.L Warner ◽  
D.A. Kudrna ◽  
S.C. Spaeth ◽  
S.S. Jones
Keyword(s):  
Triticum Aestivum ◽  
Spring Wheat ◽  
Chinese Spring ◽  
Pure Line ◽  
Triticum Aestivum L ◽  
Coat Colour ◽  
Wild Type ◽  
Cereal Species ◽  
Chinese Spring Wheat ◽  
White Mutant

AbstractRed wheats (Triticum aestivum L.) are generally more dormant and sprout resistant than white wheats. Whether this is caused by pleiotropic effectsof the red grain colour genes (R) on dormancy and coat colour, or to tight linkage between R and dormancy genes has not been fully resolved. To directly determine the effect of the R1 allele on dormancy, mutations were induced with sodium azide in a pure line selection of the red genotype (R1R1r2r2r3r3) Chinese Spring wheat. Two white mutants (CSW01, CSW02) were recovered from M3 caryopses derived from approximately 20,000 M2 plants. Both mutants were shown to be allelic to a domesticwhite genotype (r1r1r2r2r3r3). Except for seed coat colour, CSW01 and CSW02 are morphologically indistinguishable from the wild type and are presumed to be near isogenic lines of Chinese Spring. Freshly harvested grainsproduced under four different environments were evaluated for post-harvest dormancy. In all environments, intact caryopses of all three isolines exhibited high temperature dormancy typical of cereal species, although the red wild type consistently exhibited greater dormancy than the white mutant isolines. Dormancy was dissipated by afterripening in dry storage at 37°C in a similar manner for the red and white isolines. Excised embryos of the three isolines exhibited similar levels of dormancy and sensitivities to exogenous abscisic acid. These results indicate a functional R1 allele is not absolutely required for dormancy in wheat, but does enhance its expression in caryopses with dormant (sensitive) embryos

scholarly journals ABHD6 inhibition rescues a sex-dependent deficit in motor coordination in the HdhQ200/200 mouse model of Huntington’s disease

2021 ◽  
Author(s):  
Jessica K. Cao ◽  
Katie Viray ◽  
Myungsun Shin ◽  
Ku-Lung Hsu ◽  
Ken Mackie ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Motor Coordination ◽  
Motor Behavior ◽  
Wild Type ◽  
Severe Phenotype ◽  
Behavioral Deficits ◽  
Immunohistochemistry Analysis ◽  
Pump Delivery ◽  
Preliminary Study

Abstract Huntington’s Disease is associated with motor behavior deficits that current therapeutics do not alleviate. This pilot study tested if pharmacological inhibition of a/b-hydrolase domain containing 6 (ABHD6), a multifunctional enzyme expressed in the striatum, rescues behavioral deficits in HdhQ200/200 mice. Previous work has shown that this model exhibits a reduction in spontaneous locomotion and motor coordination at 8 and 10 months of age, with a more severe phenotype in female mice. Semi-quantitative immunohistochemistry analysis indicated no change in striatal ABHD6 expression at 8 months of age, but a 40% reduction by 10 months in female HdhQ200/200 mice compared to female wild-type (WT) littermates. At 8 months of age, acute ABHD6 inhibition selectively rescued motor coordination deficits in female HdhQ200/200 mice without affecting WT performance. ABHD6 inhibition did not impact spontaneous locomotion, grip strength or overall weight in either group, showing that effects were specific to motor coordination. At 10 months of age, semi-chronic ABHD6 inhibition by osmotic pump delivery also rescued motor coordination deficits in female HdhQ200/200 mice without affecting female WT littermates. Our preliminary study suggests that ABHD6 inhibition selectively improves motor performance in female HdhQ200/200 mice.

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