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https://www.readbyqxmd.com/read/28943375/independent-pseudogenization-of-cyp2j19-in-penguins-owls-and-kiwis-implicates-gene-in-red-carotenoid-synthesis
#1
Christopher A Emerling
Carotenoids have important roles in bird behavior, including pigmentation for sexual signaling and improving color vision via retinal oil droplets. Yellow carotenoids are diet-derived, but red carotenoids (ketocarotenoids) are typically synthesized from yellow precursors via a carotenoid ketolase. Recent research on passerines has provided evidence that a cytochrome p450 enzyme, CYP2J19, is responsible for this reaction, though it is unclear if this function is phylogenetically restricted. Here I provide evidence that CYP2J19 is the carotenoid ketolase common to Aves using the genomes of 65 birds and the retinal transcriptomes of 15 avian taxa...
September 21, 2017: Molecular Phylogenetics and Evolution
https://www.readbyqxmd.com/read/28928374/rethinking-the-origin-of-primates-by-reconstructing-their-diel-activity-patterns-using-genetics-and-morphology
#2
Yonghua Wu, Haifeng Wang, Haitao Wang, Elizabeth A Hadly
Phylogenetic inference typically invokes nocturnality as ancestral in primates; however, some recent studies posit that diurnality is. Here, through adaptive evolutionary analyses of phototransduction genes by using a variety of approaches (restricted branch/branch-site models and unrestricted branch-site-based models (BS-REL, BUSTED and RELAX)), our results consistently showed that ancestral primates were subjected to enhanced positive selection for bright-light vision and relatively weak selection for dim-light vision...
September 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28927431/role-of-the-sigma-1-receptor-chaperone-in-rod-and-cone-photoreceptor-degenerations-in-a-mouse-model-of-retinitis-pigmentosa
#3
Huan Yang, Yingmei Fu, Xinying Liu, Pawan K Shahi, Timur A Mavlyutov, Jun Li, Annie Yao, Steven Z-W Guo, Bikash R Pattnaik, Lian-Wang Guo
BACKGROUND: Retinitis pigmentosa (RP) is the most common inherited retinal degenerative disease yet with no effective treatment available. The sigma-1 receptor (S1R), a ligand-regulated chaperone, emerges as a potential retina-protective therapeutic target. In particular, pharmacological activation of S1R was recently shown to rescue cones in the rd10 mouse, a rod Pde6b mutant that recapitulates the RP pathology of autonomous rod degeneration followed by secondary death of cones. The mechanisms underlying the S1R protection for cones are not understood in detail...
September 19, 2017: Molecular Neurodegeneration
https://www.readbyqxmd.com/read/28895895/effects-of-sleep-quality-on-melatonin-levels-and-inflammatory-response-after-major-abdominal-surgery-in-an-intensive-care-unit
#4
Necdet Fatih Yaşar, Bartu Badak, Ağgül Canik, Sema Şanal Baş, Sema Uslu, Setenay Öner, Ersin Ateş
Disruption of nocturnal sleep in an intensive care unit may remarkably affect production of melatonin, which is also known to have anti-inflammatory properties. In the present study, we aimed to investigate the effect of sleep quality on melatonin levels and inflammation after surgery. Thus, we compared the patients, who were screened in the side-rooms where the lights were dimmed and noise levels were reduced, with the patients who received usual care. Preoperative and postoperative urine 6-sulphatoxymelatonin, serum interleukin-1 (IL-1), interleukin-6 (IL-6), and c-reactive protein (CRP) levels were measured and data on sleep quality was collected using the Richards-Campbell Sleep Questionnaire...
September 12, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28892180/long-term-exposure-to-bisphenol-s-damages-the-visual-system-and-reduces-the-tracking-capability-of-male-zebrafish-danio-rerio
#5
Wenmin Liu, Xiaona Zhang, Penghao Wei, Hua Tian, Wei Wang, Shaoguo Ru
Bisphenol S (BPS) is widely detected in aquatic environments and in human bodies. BPS has reproductive and thyroid disrupting effects, but its effect on the visual system remains unknown. In the present study, zebrafish embryos were exposed to BPS at concentrations of 1, 10, 100 and 1000 μg l(-1) until 120 days post-fertilization in a semistatic system, and the effect of BPS on the visual behavior was examined using the optokinetic response and the optomotor response tests in male zebrafish. The retinal histology, mRNA expression of photoreceptor opsin genes (zfrho, zfblue, zfgr1, zfred and zfuv) and apoptosis-related genes (bax and bcl-2) were also assessed...
September 11, 2017: Journal of Applied Toxicology: JAT
https://www.readbyqxmd.com/read/28888074/early-recovery-of-circulating-immature-b-cells-in-b-lymphoblastic-leukemia-patients-after-cd19-targeted-car-t-cell-therapy-a-pitfall-for-minimal-residual-disease-detection
#6
Wenbin Xiao, Dalia Salem, Catherine McCoy, Daniel Lee, Nirali N Shah, Maryalice Stetler-Stevenson, Constance M Yuan
BACKGROUND: CD19-targeted chimeric-antigen receptor-modified T-cells (CAR-T) are promising in the treatment of refractory B-lymphoblastic leukemia (B-ALL). Minimal residual disease (MRD) detection by multicolor flow cytometry (FCM) is critical to distinguish B-ALL MRD from regenerating, non-neoplastic B-cell populations. METHODS: FCM was performed on samples from 9 patients with B-ALL treated with CAR-T. RESULTS: All 9 patients showed response to CAR-T...
September 9, 2017: Cytometry. Part B, Clinical Cytometry
https://www.readbyqxmd.com/read/28885372/light-therapy-for-multiple-sclerosis-associated-fatigue-study-protocol-for-a-randomized-controlled-trial
#7
RANDOMIZED CONTROLLED TRIAL
Farrah J Mateen, Natalie C Manalo, Sara J Grundy, Melissa A Houghton, Gladia C Hotan, Hans Erickson, Aleksandar Videnovic
BACKGROUND: Fatigue is the most commonly reported symptom among multiple sclerosis (MS) patients, more than a quarter of whom consider fatigue to be their most disabling symptom. However, there are few effective treatment options for fatigue. We aim to investigate whether supplemental exposure to bright white light will reduce MS-associated fatigue. METHODS: Eligible participants will have clinically confirmed multiple sclerosis based on the revised McDonald criteria (2010) and a score ≥36 on the Fatigue Severity Scale (FSS)...
September 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28884199/behavioral-responses-to-visual-overstimulation-in-the-cockroach-periplaneta-americana-l
#8
Marianna Zhukovskaya, Ekaterina Novikova, Paulus Saari, Roman V Frolov
In the visual systems of insects, different types of photoreceptors contribute to specialized visual channels that mediate distinct functions and behaviors. Large compound eyes of Periplaneta americana contain photoreceptors of two spectral classes, broadband green-sensitive photoreceptors and narrow-band UV-sensitive photoreceptors. Here, we investigated how visual stimulation by UV and green light affects locomotor, resting, and grooming behaviors in P. americana under conditions when light avoidance is not possible...
September 7, 2017: Journal of Comparative Physiology. A, Neuroethology, Sensory, Neural, and Behavioral Physiology
https://www.readbyqxmd.com/read/28882754/mini-review-far-peripheral-vision
#9
Michael J Simpson
The region of far peripheral vision, beyond 60 degrees of visual angle, is important to the evaluation of peripheral dark shadows (negative dysphotopsia) seen by some intraocular lens (IOL) patients. Theoretical calculations show that the limited diameter of an IOL affects ray paths at large angles, leading to a dimming of the main image for small pupils, and to peripheral illumination by light bypassing the IOL for larger pupils. These effects are rarely bothersome, and cataract surgery is highly successful, but there is a need to improve the characterization of far peripheral vision, for both pseudophakic and phakic eyes...
September 9, 2017: Vision Research
https://www.readbyqxmd.com/read/28878937/contrast-sensitivity-to-spatial-gratings-in-moderate-and-dim-light-conditions-in-patients-with-diabetes-in-the-absence-of-diabetic-retinopathy
#10
Sare Safi, Anoushiravan Rahimi, Afsaneh Raeesi, Hamid Safi, Mohammad Aghazadeh Amiri, Mojtaba Malek, Mehdi Yaseri, Mohammad Haeri, Frank A Middleton, Eduardo Solessio, Hamid Ahmadieh
OBJECTIVE: To evaluate the ability of contrast sensitivity (CS) to discriminate loss of visual function in diabetic subjects with no clinical signs of retinopathy relative to that of normal subjects. RESEARCH DESIGN AND METHODS: In this prospective cross-sectional study, we measured CS in 46 diabetic subjects with a mean age of 48±6 years, a best-corrected visual acuity of 20/20 and no signs of diabetic retinopathy. The CS in these subjects was compared with CS measurements in 46 normal control subjects at four spatial frequencies (3, 6, 12, 18 cycles per degree) under moderate (500 lux) and dim (less than 2 lux) background light conditions...
2017: BMJ Open Diabetes Research & Care
https://www.readbyqxmd.com/read/28856684/selective-synaptic-connections-in-the-retinal-pathway-for-night-vision
#11
Deborah L Beaudoin, Mania Kupershtok, Jonathan B Demb
The mammalian retina encodes visual information in dim light using rod photoreceptors and a specialized circuit: rods→rod bipolar cells→AII amacrine cell. The AII amacrine cell uses sign-conserving electrical synapses to modulate ON cone bipolar cell terminals and sign-inverting chemical (glycinergic) synapses to modulate OFF cone cell bipolar terminals; these ON and OFF cone bipolar terminals then drive the output neurons, retinal ganglion cells (RGCs), following light increments and decrements, respectively...
August 30, 2017: Journal of Comparative Neurology
https://www.readbyqxmd.com/read/28844643/dopamine-regulation-of-gabaa-receptors-contributes-to-light-dark-modulation-of-the-on-cone-bipolar-cell-receptive-field-surround-in-the-retina
#12
Antoine Chaffiol, Masaaki Ishii, Yu Cao, Stuart C Mangel
Cone bipolar cells are interneurons that receive synaptic input from cone photoreceptor cells and provide the output of the first synaptic layer of the retina. These cells exhibit center-surround receptive fields, a prototype of lateral inhibition between neighboring sensory cells in which stimulation of the receptive field center excites the cell whereas stimulation of the surrounding region laterally inhibits the cell. This fundamental sensory coding mechanism facilitates spatial discrimination and detection of stimulus edges...
September 11, 2017: Current Biology: CB
https://www.readbyqxmd.com/read/28821594/lazy-genes-mediate-the-effects-of-gravity-on-auxin-gradients-and-plant-architecture
#13
Takeshi Yoshihara, Edgar P Spalding
A rice mutant led to the discovery of a plant-specific LAZY1 protein that controls the orientation of shoots. Arabidopsis thaliana possesses six LAZY genes having spatially distinct expression patterns. Branch angle phenotypes previously associated with single LAZY genes were here studied in roots and shoots of single and higher-order atlazy mutants. The results identify the major contributors to root and shoot branch angles and gravitropic behavior of seedling hypocotyls and primary roots. AtLAZY1 is the principal determinant of inflorescence branch angle...
August 18, 2017: Plant Physiology
https://www.readbyqxmd.com/read/28801634/mapping-physiological-inputs-from-multiple-photoreceptor-systems-to-dopaminergic-amacrine-cells-in-the-mouse-retina
#14
Xiwu Zhao, Kwoon Y Wong, Dao-Qi Zhang
In the vertebrate retina, dopamine is synthesized and released by a specialized type of amacrine cell, the dopaminergic amacrine cell (DAC). DAC activity is stimulated by rods, cones, and melanopsin-expressing intrinsically photosensitive retinal ganglion cells upon illumination. However, the relative contributions of these three photoreceptor systems to the DAC light-induced response are unknown. Here we found that rods excite dark-adapted DACs across a wide range of stimulation intensities, primarily through connexin-36-dependent rod pathways...
August 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28790405/differential-impact-in-young-and-older-individuals-of-blue-enriched-white-light-on-circadian-physiology-and-alertness-during-sustained-wakefulness
#15
Virginie Gabel, Carolin F Reichert, Micheline Maire, Christina Schmidt, Luc J M Schlangen, Vitaliy Kolodyazhniy, Corrado Garbazza, Christian Cajochen, Antoine U Viola
We tested the effect of different lights as a countermeasure against sleep-loss decrements in alertness, melatonin and cortisol profile, skin temperature and wrist motor activity in healthy young and older volunteers under extendend wakefulness. 26 young [mean (SE): 25.0 (0.6) y)] and 12 older participants [(mean (SE): 63.6 (1.3) y)] underwent 40-h of sustained wakefulness during 3 balanced crossover segments, once under dim light (DL: 8 lx), and once under either white light (WL: 250 lx, 2,800 K) or blue-enriched white light (BL: 250 lx, 9,000 K) exposure...
August 8, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28774755/human-seasonal-and-circadian-studies-in-antarctica-halley-75%C3%A2-s
#16
Josephine Arendt, Benita Middleton
Living for extended periods in Antarctica exposes base personnel to extremes of daylength (photoperiod) and temperature. At the British Antarctic Survey base of Halley, 75°S, the sun does not rise for 110d in the winter and does not set for 100d in summer. Photoperiod is the major time cue governing the timing of seasonal events such as reproduction in many species. The neuroendocrine signal providing photoperiodic information to body physiology is the duration of melatonin secretion which reflects the length of the night: longer in the short days of winter and shorter in summer...
August 1, 2017: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/28770653/simple-lighting-manipulations-facilitate-behavioral-entrainment-of-mice-to-18-h-days
#17
Thijs J Walbeek, Michael R Gorman
In an invariantly rhythmic world, a robust and stable mammalian circadian clock is presumed to confer fitness advantages. In shift-work or after rapid transmeridian travel, however, a stable clock might be maladaptive and a more flexibly resettable clock may have advantages. The rate at which rodents can adjust to simulated time zone travel and the range of entrainment can be markedly increased through simple light manipulations, namely, by exposing animals to extremely dim light (<0.01 lux) at night or by bifurcating rhythms under 24-h light-dark-light-dark (LDLD) cycles...
July 1, 2017: Journal of Biological Rhythms
https://www.readbyqxmd.com/read/28760697/vision-in-laboratory-rodents-tools-to-measure-it-and-implications-for-behavioral-research
#18
REVIEW
Henri Leinonen, Heikki Tanila
Mice and rats are nocturnal mammals and their vision is specialized for detection of motion and contrast in dim light conditions. These species possess a large proportion of UV-sensitive cones in their retinas and the majority of their optic nerve axons target superior colliculus rather than visual cortex. Therefore, it was a widely held belief that laboratory rodents hardly utilize vision during day-time behavior. This dogma is being questioned as accumulating evidence suggests that laboratory rodents are able to perform complex visual functions, such as perceiving subjective contours, and that declined vision may affect their performance in many behavioral tasks...
July 28, 2017: Behavioural Brain Research
https://www.readbyqxmd.com/read/28747438/palmitoylation-is-a-prerequisite-for-dimerization-dependent-raftophilicity-of-rhodopsin
#19
Keiji Seno, Fumio Hayashi
The visual photopigment rhodopsin (Rh) is a prototypical G protein-coupled receptor (GPCR) responsible for initiation of the phototransduction cascade in rod photoreceptors. Similar to other GPCRs, Rh can form dimers or even higher oligomers and tends to have a supramolecular organization that is likely important in the dim light response. Rh also exhibits high affinity for lipid rafts (i.e. raftophilicity) upon light-dependent binding with the cognate G protein transducin (Gt), suggesting the presence of lipid raft-like domains in the retinal disk membrane and their importance in phototransduction...
September 15, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28739369/genomic-regression-of-claw-keratin-taste-receptor-and-light-associated-genes-provides-insights-into-biology-and-evolutionary-origins-of-snakes
#20
Christopher A Emerling
Regressive evolution of anatomical traits often corresponds with the regression of genomic loci underlying such characters. As such, studying patterns of gene loss can be instrumental in addressing questions of gene function, resolving conflicting results from anatomical studies, and understanding the evolutionary history of clades. The evolutionary origins of snakes involved the regression of a number of anatomical traits, including limbs, taste buds and the visual system, and by analyzing serpent genomes, I was able to test three hypotheses associated with the regression of these features...
July 21, 2017: Molecular Phylogenetics and Evolution
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