-
Brazilian Journal of Biology = Revista... 2023A little-studied characteristic of the Mexican native fish Dormitator latifrons is the effect that the color of the bottom or lining of ponds or tubs can have on their...
A little-studied characteristic of the Mexican native fish Dormitator latifrons is the effect that the color of the bottom or lining of ponds or tubs can have on their growth and blood parameters under controlled conditions. After a quarantine period in prophylactic treatment, an initial assay was performed. The organisms were grouped into four treatments (white, yellow, blue, and black) in triplicate, with 30 individuals with an average weight of 34.7± 2.5 g and average size of 12.5 ± 1.5 cm per tank. The trial lasted 60 days, after which a final biometry to all specimens and blood extractions to six random organisms per tank were performed. The following hematological and blood chemistry parameters were evaluated: erythrocytes, cell counts, and differential counts, as well as glucose, albumin, a/g ratio, and total proteins. Final weight, weight gain, and specific growth rate presented statistical differences between treatments (p<0.05), with dark bottoms (blue and black) above 80% of WG and above 1.0 of SGR. No statistically differences were found in hematological blood chemistry parameters (p>0.05). The growth results suggest that dark pond bottoms promote the adaptation of Dormitator latifrons by allowing it to avoid detection by predators through the adoption of a cryptic coloration. However, the species shows a great capacity for crypsis, being able to change its pigmentation to adapt to different bottom colors.
Topics: Animals; Ponds; Fishes; Perciformes; Mexico
PubMed: 37937625
DOI: 10.1590/1519-6984.274004 -
Plant Physiology Feb 2024In plants, sucrose nonfermenting 1 (SNF1)-related protein kinase 1 (SnRK1) is a key energy sensor that orchestrates large-scale transcriptional reprograming to maintain...
In plants, sucrose nonfermenting 1 (SNF1)-related protein kinase 1 (SnRK1) is a key energy sensor that orchestrates large-scale transcriptional reprograming to maintain cellular homeostasis under energy deficit. SnRK1 activity is under tight negative control, although the exact mechanisms leading to its activation are not well understood. We show that the Arabidopsis (Arabidopsis thaliana) DOMAIN OF UNKNOWN FUNCTION (DUF581) protein DUF581-9/FCS-like zinc finger 3 binds to the catalytic SnRK1.1 α subunit (KIN10) to inhibit its activation by geminivirus rep-interacting kinase (GRIK)-dependent T-loop phosphorylation. Overexpression of DUF581-9 in Arabidopsis dampens SnRK1 signaling and interferes with adaptation to dark-induced starvation. The presence of DUF581-9 significantly reduced SnRK1 activity in protoplasts and in vitro. This was accompanied by a reduction in T175 T-loop phosphorylation and also diminished KIN10 auto-phosphorylation. Furthermore, DUF581-9 reduced binding of the upstream activating kinase GRIK2 to KIN10, explaining the reduced KIN10 T-loop phosphorylation. Ectopically expressed DUF581-9 protein was rapidly turned over by the proteasome when Arabidopsis plants were subjected to starvation treatment, likely releasing its inhibitory activity on the SnRK1 complex. Taken together, our results support a model in which DUF581-9 negatively regulates SnRK1 activity under energy sufficient conditions. Turnover of the protein provides a rapid way for SnRK1 activation under energy deficit without the need of de novo protein synthesis.
Topics: Phosphorylation; Arabidopsis; Catalysis; Catalytic Domain; Cytoplasm; Protein Serine-Threonine Kinases; Arabidopsis Proteins
PubMed: 37936321
DOI: 10.1093/plphys/kiad594 -
PeerJ 2023Artificial light at night (ALAN) is a novel environmental stressor of global concern. Various sources of artificial light are now common in urbanized areas and have...
BACKGROUND
Artificial light at night (ALAN) is a novel environmental stressor of global concern. Various sources of artificial light are now common in urbanized areas and have diverse negative effects on many species of animals and plants. However, ALAN has also been shown to have no effect or a positive effect on some organisms. This study investigates the impact of ALAN on the growth and leaf pigmentation of a common floating freshwater plant species.
METHODS
We exposed wild-derived dotted duckweed () to either darkness during the night (Control group) or to artificial light at night (ALAN group) for 49 days. We set up two large boxes of eighty samples each with 2-3 leaves of duckweed in each sample at the start of the experiment. The ALAN box had an opaque lid with a small lamp that was turned on at night. The Control box was also covered at night with an opaque lid but without a lamp. During the day, plants in both boxes were exposed to natural light. We counted the number of leaves in each sample weekly. We took photos of the samples on day 28 to measure the total leaf surface area per sample. On day 49, we took photos of the underside of the leaves for analyses of the relative levels of dark pigmentation across all samples.
RESULTS
We found that ALAN-exposed plant samples had, on average, more leaves than control plants after a few weeks of exposure. They also had a more variable number of leaves per sample. The total leaf area per sample on day 28 was larger in the ALAN samples. The underside of the leaves on day 49 was, on average, darker in the ALAN plants than in the control plants.
CONCLUSION
There is a significant growth-enhancing effect from exposure to artificial light at night on . However, higher variability induced by ALAN exposure indicates that ALAN is also a stressful condition for these plants. This is in line with our finding of the presence of larger amounts of dark pigments in the leaves of ALAN-exposed plants. Dark pigmentation in duckweed species could be a defence mechanism protecting tissues from stress-induced oxidative damage. Overall, both positive and negative effects of ALAN can be observed simultaneously in different traits of the same organism. Increased individual variation can facilitate population-level adaptation to stressful conditions. As such, this work contributes to our knowledge of the effects of light pollution in urban environments on common plants.
Topics: Animals; Light Pollution; Plants; Plant Leaves; Pigmentation
PubMed: 37927782
DOI: 10.7717/peerj.16371 -
Documenta Ophthalmologica. Advances in... Feb 2024Both rod and cone-driven signals contribute to the electroretinogram (ERG) elicited by a standard strong flash in the dark. Negative ERGs usually reflect inner retinal...
PURPOSE
Both rod and cone-driven signals contribute to the electroretinogram (ERG) elicited by a standard strong flash in the dark. Negative ERGs usually reflect inner retinal dysfunction. However, in diseases where rod photoreceptor function is selectively lost, a negative waveform might represent the response of the dark-adapted cone system. To investigate the dark-adapted cone-driven waveform in healthy individuals, we delivered flashes on a dim blue background, designed to saturate the rods, but minimally adapt the cones.
METHODS
ERGs were recorded, using conductive fibre electrodes, in adults from the TwinsUK cohort. Responses to 13 cd m s white xenon flashes (similar to the standard DA 10 flash), delivered on a blue background, were analysed. Photopic and scotopic strengths of the background were 1.3 and 30 cd m, respectively; through a dilated pupil, this is expected to largely saturate the rods, but adapt the cones much less than the standard ISCEV background.
RESULTS
Mean (SD) participant age was 62.5 (11.3) years (93% female). ERGs from 203 right and 204 left eyes were included, with mean (SD) b/a ratios of 1.22 (0.28) and 1.18 (0.28), respectively (medians, 1.19 and 1.17). Proportions with negative waveforms were 23 and 26%, respectively. Right and left eye b/a ratios were strongly correlated (correlation coefficient 0.74, p < 0.0001). We found no significant correlation of b/a ratio with age.
CONCLUSIONS
Over 20% of eyes showed b/a ratios less than 1, consistent with the notion that dark-adapted cone-driven responses to standard bright flashes can have negative waveforms. The majority had ratios greater than 1. Thus, whilst selective loss of rod function can yield a negative waveform (with reduced a-wave) in some, our findings also suggest that loss of rod function can occur without necessarily yielding a negative ERG. One potential limitation is possible mild cone system adaptation by the background.
Topics: Adult; Humans; Female; Middle Aged; Male; Electroretinography; Prevalence; Dark Adaptation; Photic Stimulation; Retinal Cone Photoreceptor Cells
PubMed: 37924416
DOI: 10.1007/s10633-023-09957-4 -
Cureus Oct 2023Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit, which includes the hair follicle, hair shaft and sebaceous gland. The only treatment that has...
BACKGROUND
Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit, which includes the hair follicle, hair shaft and sebaceous gland. The only treatment that has an effect on all the main aetiological causes of acne is isotretinoin. However, it may have a variety of negative side effects. The aim of this study was to evaluate the knowledge and attitudes of dermatologists regarding ocular effects following isotretinoin prescribing in the Aseer region, Saudi Arabia.
METHODOLOGY
An anonymous online cross-sectional survey was conducted in August 2022 to investigate dermatologists' knowledge and attitude regarding isotretinoin-related ocular side effects in Aseer, Saudi Arabia. Participants were recruited using convenience and snowball sampling methods.
RESULTS
A total of 48 dermatologists were included in this survey. The age distribution ranged from 25 to over 60 years. Sixteen (37.5%) were aged 31-40 years, 29 (60.4%) were male and 20 (41.7%) were specialists. All dermatologists reported that it can cause dry eye, 32 (66.7%) reported that it can cause contact lens intolerance, 10 (20.8%) reported that it can cause a decrease in dark adaptation and two (4.2%) thought that it can cause ectopia lentis and retinoblastoma. Regarding attitude, 43 (87.5%) thought that a course of isotretinoin is not recommended if the patient has recently undergone refractive surgery, 30 (62.5%) always inform patients about ocular side effects, 31 (72.9%) do not consider referring patients for ophthalmic examinations before initiating isotretinoin, 12 (25.0%) always prescribe lubricant eye drops, 15 (31.3%) always ask patients about recent refractive surgery, 17 (35.4%) always warn patients about avoiding refractive surgery during isotretinoin use and 19 (39.6%) always inform patients concerning discomfort with contact lenses.
CONCLUSIONS
The survey reveals that dermatologists in Aseer, Saudi Arabia, generally have good knowledge of isotretinoin related to some ocular side effects, especially dry eye and contact lens intolerance. However, there is some variation in their practices with regard to patient education, referrals for ophthalmic examinations, the use of lubricant eye drops and refractive surgery during isotretinoin treatment. Thus, dermatologists should receive educational training on the safety profile of isotretinoin while managing acne vulgaris.
PubMed: 37920642
DOI: 10.7759/cureus.46335 -
Investigative Ophthalmology & Visual... Oct 2023To assess the progression in functional and structural measures over a five-year period in patients with retinal dystrophy caused by RLBP1 gene mutation.
PURPOSE
To assess the progression in functional and structural measures over a five-year period in patients with retinal dystrophy caused by RLBP1 gene mutation.
METHODS
This prospective, noninterventional study included patients with biallelic RLBP1 mutations from two clinical sites in Sweden and Canada. Key assessments included ocular examinations, visual functional measures (best-corrected visual acuity [BCVA], contrast sensitivity [CS], dark-adaptation [DA] kinetics up to six hours for two wavelengths [450 and 632 nm], Humphrey visual fields [HVF], full-field flicker electroretinograms), and structural ocular assessments.
RESULTS
Of the 45 patients enrolled, 38 completed the full five years of follow-up. At baseline, patients had BCVA ranging from -0.2 to 1.3 logMAR, poor CS, HVF defects, and prominent thinning in central foveal thickness. All patients had extremely prolonged DA rod recovery of approximately six hours at both wavelengths. The test-retest repeatability was high across all anatomic and functional endpoints. Cross-sectionally, poorer VA was associated with older age (right eye, correlation coefficient [CC]: 0.606; left eye, CC: -0.578; P < 0.001) and HVF MD values decreased with age (right eye, CC: -0.672, left eye, CC: -0.654; P < 0.001). However, no major changes in functional or structural measures were noted longitudinally over the five-year period.
CONCLUSIONS
This natural history study, which is the first study to monitor patients with RLBP1 RD for five years, showed that severely delayed DA sensitivity recovery, a characteristic feature of this disease, was observed in all patients across all age groups (17-69 years), making it a potentially suitable efficacy assessment for gene therapy treatment in this patient population.
Topics: Humans; Adolescent; Young Adult; Adult; Middle Aged; Aged; Prospective Studies; Visual Fields; Visual Acuity; Retinitis Pigmentosa; Retinal Dystrophies
PubMed: 37883093
DOI: 10.1167/iovs.64.13.42 -
Proceedings. Biological Sciences Oct 2023Members of the phylum Cnidaria include sea anemones, corals and jellyfish, and have successfully colonized both marine and freshwater habitats throughout the world. The...
Members of the phylum Cnidaria include sea anemones, corals and jellyfish, and have successfully colonized both marine and freshwater habitats throughout the world. The understanding of how cnidarians adapt to extreme environments such as the dark, high-pressure deep-sea habitat has been hindered by the lack of genomic information. Here, we report the first chromosome-level deep-sea cnidarian genome, of the anemone sp., which was 1.39 Gbp in length and contained 44 970 gene models including 14 806 tRNA genes and 30 164 protein-coding genes. Analyses of homeobox genes revealed the longest chromosome hosts a mega-array of Hox cluster, HoxL, NK cluster and NKL homeobox genes; until now, such an array has only been hypothesized to have existed in ancient ancestral genomes. In addition to this striking arrangement of homeobox genes, analyses of microRNAs revealed cnidarian-specific complements that are distinctive for nested clades of these animals, presumably reflecting the progressive evolution of the gene regulatory networks in which they are embedded. Also, compared with other sea anemones, circadian rhythm genes were lost in sp., which likely reflects adaptation to living in the dark. This high-quality genome of a deep-sea cnidarian thus reveals some of the likely molecular adaptations of this ecologically important group of metazoans to the extreme deep-sea environment. It also deepens our understanding of the evolution of genome content and organization of animals in general and cnidarians in particular, specifically from the viewpoint of key developmental control genes like the homeobox-encoding genes, where we find an array of genes that until now has only been hypothesized to have existed in the ancient ancestor that pre-dated both the cnidarians and bilaterians.
Topics: Animals; Sea Anemones; Genes, Homeobox; Phylogeny; Evolution, Molecular; Multigene Family; Cnidaria
PubMed: 37876192
DOI: 10.1098/rspb.2023.1563 -
Heliyon Oct 2023To investigate the feasibility and effectiveness of hydrogen in the treatment of retinitis pigmentosa (RP) patients through the drinking of hydrogen-rich water (HRW).
OBJECTIVE
To investigate the feasibility and effectiveness of hydrogen in the treatment of retinitis pigmentosa (RP) patients through the drinking of hydrogen-rich water (HRW).
METHODS
RP patients clinically diagnosed in our hospital were selected and given HRW for drinking at 400-500 ml twice a day for four consecutive weeks. Changes in best corrected visual acuity (BCVA), intraocular pressure, the retinal thickness, and choroidal thickness, as well as the amplitude and peak time of visual electrophysiological examinations before and after HRW drinking were observed. Data were statistically analyzed.
RESULTS
In total, 24 eyes of 13 patients with RP (3 males and 10 females aged-27-65 years old, were enrolled in the study. The BCVA after HRW drinking was 0.34 ± 0.25, which was statistically improved compared with that before ( < 0.05). There were no significant differences in intraocular pressure, retinal lhickness, or choroidal thickness before and after HRW drinking (all > 0.05). The amplitudes of the b-wave in Dark-adaptation 0.01 response, a and b waves in Dark-adaptation 3.0 response, the Dark-adaptation Ops total wave, a and b waves in Light-adaptation 3.0 response, and the Light-adaptation Flicker response of electroretinogram (ERG) were significantly higher than those before HRW drinking (all < 0.05). The corresponding peak times iwere mproved to some extent compared to those before HRW consumption (all < 0.05). Six patients with RP (11 eyes) had a BCVAm ore than 20/200. The amplitude and peak time of the P100 -ave from the 1°p attern visual evoked potentials (PVEP) were not significantly different from those before HRW drinking ( > 0.05), while the data from the 15' PVEP were statistically different ( < 0.05). Seven patients with RP (13 eyes) had a BCVA less than. 20/200 No significant differences were found in the amplitude and peak time of the P2 wave from the 1.0 Hz flash visual evoked potentials (FVEP) and the amplitude from the 12 Hz FVEP compared with those before HRW drinking (all > 0.05).
CONCLUSION
Short-term HRW drinking slightly improved visual function in patients with primary RP, whereas no significant improvement was found in the thickness of the retina and choroid.
PubMed: 37860576
DOI: 10.1016/j.heliyon.2023.e20671 -
Proceedings. Biological Sciences Oct 2023Mammalian hibernation is a survival strategy characterized by metabolic suppression and drastically lowering body temperature (Tb), used during harsh seasons with food...
Mammalian hibernation is a survival strategy characterized by metabolic suppression and drastically lowering body temperature (Tb), used during harsh seasons with food shortages and cold. The Syrian hamster commences hibernation in response to a short photoperiod and cold but spontaneously concludes hibernation after several months without environmental cues. Little is known about the changes in diel rhythms during hibernation. Using long-term and high-resolution Tb data, we analysed the diel Tb rhythm time-course changes in Syrian hamsters raised under summer-like conditions (long photoperiod (LP) and warm; LP-warm) and transferred to winter-like conditions (short photoperiod (SP) and cold; SP-cold). The diel Tb rhythm was undetectable during the hibernation period (HIBP), reappearing after the HIBP. The phase of this returning rhythm reverted to the LP entrainment phase characteristics despite the ambient SP and then re-entrained to the ambient SP as if the hamsters were transferred from the LP-warm to SP-cold conditions. The diel Tb rhythm reverted from the SP- to LP-type in a hibernation-dependent manner. Under constant dark and cold conditions, the circadian Tb rhythm recovered without photic stimuli following the HIBP. These findings suggest that hibernation involves a program that anticipates the ambient photoperiod when animals emerge from hibernation.
Topics: Cricetinae; Animals; Mesocricetus; Body Temperature; Hibernation; Seasons; Circadian Rhythm; Photoperiod
PubMed: 37848068
DOI: 10.1098/rspb.2023.0922 -
Frontiers in Physiology 2023Environmental enrichment (EE) for rodents involves housing conditions that facilitate enhanced sensory, cognitive, and motor stimulation relative to standard housing...
Environmental enrichment (EE) for rodents involves housing conditions that facilitate enhanced sensory, cognitive, and motor stimulation relative to standard housing conditions. A recent study suggested that EE induces muscle hypertrophy. However, it remains unclear whether muscle hypertrophy in EE is associated with voluntary physical activity, and the characteristics of muscle adaptation to EE remain unclarified. Therefore, this study investigated whether muscle adaptation to EE is associated with voluntary physical activity, and assessed the changes in the muscle fiber-type distribution and fiber-type-specific cross-sectional area in response to EE. Wistar rats (6 weeks of age) were randomly assigned to either the standard environment group (n = 10) or the EE group (n = 10). The voluntary physical activity of rats housed in EE conditions was measured using a recently developed three-axis accelerometer. After exposure to the standard or enriched environment for 30 days, the tibialis anterior, extensor digitorum longus, soleus, plantaris, and gastrocnemius muscles were removed and weighed. Immunohistochemistry analysis was performed on the surface (anterior) and deep (posterior) areas of the tibialis anterior and soleus muscles. The EE group showed increased voluntary physical activity during the dark period compared with the standard environment group ( = 0.005). EE induced muscle mass gain in the soleus muscle ( = 0.002) and increased the slow-twitch muscle fiber cross-sectional area of the soleus muscle ( = 0.025). EE also increased the distribution of high-oxidative type IIa fibers of the surface area ( = 0.001) and type I fibers of the deep area ( = 0.037) of the tibialis anterior muscle. These findings suggest that EE is an effective approach to induce slow-twitch muscle fiber hypertrophy through increased daily voluntary physical activity.
PubMed: 37841318
DOI: 10.3389/fphys.2023.1265871