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Plant Signaling & Behavior Dec 2023Drought stress adversely affects plant growth, often leading to total crop failure. Upon sensing soil water deficits, plants switch on biosynthesis of abscisic acid...
Drought stress adversely affects plant growth, often leading to total crop failure. Upon sensing soil water deficits, plants switch on biosynthesis of abscisic acid (ABA), a stress hormone for drought adaptation. Here, we used exogenous ABA application to dark-grown sorghum cell suspension cultures as an experimental system to understand how a drought-tolerant crop responds to ABA. We evaluated intracellular and secreted proteins using isobaric tags for relative and absolute quantification. While the abundance of only ~ 7% (46 proteins) intracellular proteins changed in response to ABA, ~32% (82 proteins) of secreted proteins identified in this study were ABA responsive. This shows that the extracellular matrix is disproportionately targeted and suggests it plays a vital role in sorghum adaptation to drought. Extracellular proteins responsive to ABA were predominantly defense/detoxification and cell wall-modifying enzymes. We confirmed that sorghum plants exposed to drought stress activate genes encoding the same proteins identified in the cell culture system with ABA. Our results suggest that ABA activates defense and cell wall remodeling systems during stress response. This could underpin the success of sorghum adaptation to drought stress.
Topics: Abscisic Acid; Sorghum; Water; Edible Grain; Plant Proteins; Droughts; Stress, Physiological; Gene Expression Regulation, Plant
PubMed: 38100609
DOI: 10.1080/15592324.2023.2291618 -
Scientific Reports Dec 2023We present clinical evaluation of a mobile app for dark adaptation (DA) measurement in age-related macular degeneration (AMD) patients and in older adults...
We present clinical evaluation of a mobile app for dark adaptation (DA) measurement in age-related macular degeneration (AMD) patients and in older adults (age > 50 years) without AMD or other retinal disorders (NV). The outcome measures were the area under dark adaptation curve (AUDAC) and the time for visual sensitivity to recover by 3 log units (T). Larger AUDAC and T values indicated worse DA response. The association of AUDAC with AMD was analyzed using linear regression, while time-to-event analysis was used for T. 32 AMD patients (mean ± SD; age:72 ± 6.3 years, VA:0.09 ± 0.08 logMAR) and 25 NV subjects (mean ± sd; age:65 ± 8.7 years, VA:0.049 ± 0.07 logMAR) were measured with the app. Controlling for age, VA, and cataract severity, the AMD presence was significantly associated with higher AUDAC (β = 0.41, 95% CI 0.18-0.64, p = 0.001) and with slower sensitivity recovery (β = 0.32, 95% CI 0.15-0.69, p = 0.004). DA measurements with the app were highly correlated with those obtained with AdaptDx-an established clinical device (n = 18, ρ = 0.87, p < 0.001). AMD classification accuracy using the app was 72%, which was comparable to the 71% accuracy of AdaptDx. Our findings indicate that the mobile app provided reliable and clinically meaningful DA measurements that were strongly correlated with the current standard of care in AMD.
Topics: Humans; Aged; Middle Aged; Dark Adaptation; Mobile Applications; Visual Acuity; Cross-Sectional Studies; Macular Degeneration
PubMed: 38092820
DOI: 10.1038/s41598-023-48898-5 -
Ecology and Evolution Dec 2023Colour change is used by a wide range of animals. It is used for intra- and interspecific communication and crypsis, and can occur on morphological and physiological...
Colour change is used by a wide range of animals. It is used for intra- and interspecific communication and crypsis, and can occur on morphological and physiological levels. Bony fish employ rapid physiological colour change and display various types of patterns and colouration (colour phases) useful for aposematic and cryptic purposes. Using an existing database of benthic stereo-baited remote underwater video systems from two locations in Western Australia, we tested whether the frequency of colour phases of emperors, Lethrinidae, varied by species. We described colour phases and rapid physiological colour change in 16 species of lethrinids, and related occurrences of colour change to feeding activity and life stages. Dark and light colour phases were observed in nine of the 16 evaluated species of which seven also displayed physiological colour change. Frequency of colour phases varied between species, suggesting that the display of different dark patterns may be especially important for certain species. Both juveniles and adults showed the ability to change between different colour patterns. The change into a mottled pattern mainly occurred while feeding or when approaching to feed, suggesting that it may be triggered by feeding and the associated decrease in environmental awareness. Colour change is a commonly observed strategy in lethrinids and may have evolved as an adaptation for increased foraging success or to reduce aggression from conspecifics. Physiological colour change allows lethrinids to quickly adapt to various cues from the environment and can therefore be considered a versatile physiological mechanism in this family.
PubMed: 38077506
DOI: 10.1002/ece3.10735 -
Plants (Basel, Switzerland) Nov 2023Polyploidy is a significant evolutionary process in plants that involves the duplication of genomic content and has been recognized as a key mechanism driving plant...
Polyploidy is a significant evolutionary process in plants that involves the duplication of genomic content and has been recognized as a key mechanism driving plant diversification and adaptation. In natural populations, polyploids frequently arise from unreduced gametes, which subsequently fuse with reduced or unreduced gametes, resulting in triploid or tetraploid offspring, respectively. L. is a diploid species, but recent work using artificially induced polyploidy has demonstrated its potential advantages in an agricultural setting. Further, recent work has identified that some elite clonal cultivars, vis. Mac1, are triploid, with no indication that they were artificially produced. The current study was conducted to determine if polyploidy is a naturally occurring phenomenon in cannabis and to estimate the frequency of this phenomenon across populations. To do this, the presence of natural triploid individuals was evaluated in 13 seedling populations of cannabis using a flow cytometry analysis. Among the examined populations, natural triploids were identified in 10 groups with an average frequency of approximately 0.5%. The highest frequency of natural triploids was observed in a self-pollinated population at 2.3%. This research demonstrates that polyploidy is a naturally occurring event in cannabis and triploids are present at an average of approximately 0.5%, or 1 in 200 plants. These data shed light on the natural variation in ploidy within cannabis populations and contribute valuable insights to the understanding of cannabis genetics and breeding practices.
PubMed: 38068564
DOI: 10.3390/plants12233927 -
Frontiers in Neuroscience 2023To test the hypothesis that rod photoreceptor mitochondria function progressively declines over time.
PURPOSE
To test the hypothesis that rod photoreceptor mitochondria function progressively declines over time.
METHODS
2, 12, and 24 month-old dark- and light-adapted C57BL/6J (B6J) mice were examined by OCT. We measured (i) an index of mitochondrial configuration within photoreceptors measured from the profile shape aspect ratio (MCP/AR) of the hyperreflective band posterior to the external limiting membrane (ELM), (ii) a proxy for energy-dependent pH-triggered water removal, the thickness of the ELM-retinal pigment epithelium (ELM-RPE), and its correlate (iii) the hyporeflective band (HB) signal intensity at the photoreceptor tips. Visual performance was assessed by optokinetic tracking.
RESULTS
In 2 and 24 month-old mice, MCP/AR in both inferior and superior retina was smaller in light than in dark; no dark-light differences were noted in 12 month-old mice. Dark-adapted inferior and superior, and light-adapted superior, ELM-RPE thickness increased with age. The dark-light difference in ELM-RPE thickness remained constant across all ages. All ages showed a decreased HB signal intensity magnitude in dark relative to light. In 12 month-old mice, the dark-light difference in HB magnitude was greater than in younger and older mice. Anatomically, outer nuclear layer thickness decreased with age. Visual performance indices were reduced at 24 month-old compared to 2 month-old mice.
CONCLUSION
While the working hypothesis was not supported herein, the results raise the possibility of a mid-life adaptation in rod mitochondrial function during healthy aging in B6J mice based on OCT biomarkers, a plasticity that occurred prior to declines in visual performance.
PubMed: 38046657
DOI: 10.3389/fnins.2023.1280453 -
PloS One 2023People quickly and involuntarily form impressions of others based on their facial physical attributes, which can modulate critical social interactions. Skin pigmentation...
People quickly and involuntarily form impressions of others based on their facial physical attributes, which can modulate critical social interactions. Skin pigmentation is one of the most variable and conspicuous facial traits among human populations. Empirical evidence suggests that these variations reflect ancestral ecological selective pressures balancing cutaneous vitamin D synthesis with the protection of the dermis from ultraviolet radiation. Nevertheless, skin pigmentation may currently be subject to additional selective pressures. For instance, the colonial era in Central and South America developed a highly stratified society based on ethnic origins, and light skin pigmentation became associated with higher social status and deference. This association could have originated through historical social learning that promoted favorable social perceptions towards individuals with lighter skin color and unfavorable perceptions towards individuals with darker skin color, which could still be present in the perception of current populations. Facial skin pigmentation is also sexually dimorphic, with males tending to exhibit darker skin than females, a difference that could be driven by sexual selection. To explore whether social learning and sexual selection represent additional selective pressures on skin pigmentation, we tested how this facial trait influences fundamental social perceptions in a Mexican population (N = 700, 489 female). We sampled facial images of eight European American males with natural lighter facial skin and eight males from an indigenous pre-Columbian community from Mexico, the Me'Phaa, with natural darker facial skin. We produced stimuli from these images by varying the skin pigmentation while preserving the facial shape. Stimuli were rated on attractiveness, trustworthiness, perceived health, dominance, aggressiveness, and femininity/masculinity. We found that the natural light-skinned faces were perceived as more attractive, trustworthy, and healthy but less dominant than the natural dark faces. Furthermore, by varying the facial skin color in these original groups, we altered the perceptions of them, mainly their attractiveness. These results partially support the hypothesis that dark facial skin color may help males compete for mates. Also, the results strongly support the view that lighter facial skin color became associated with social benefits through social learning in this Mexican population. Our findings, when viewed through the lens of cultural evolution, align with previous research in social psychology and anthropology. They hold the potential to offer a comprehensive understanding of the origin of this social phenomenon of cultural transmission, which currently plays a role in the formation of racial attitudes, stereotyping, and racial inequality in Mexican and other Latin American populations.
Topics: Male; Animals; Humans; Female; Skin Pigmentation; Judgment; Ultraviolet Rays; Mexico; Masculinity; Hominidae; Social Perception
PubMed: 38032952
DOI: 10.1371/journal.pone.0279858 -
The Science of the Total Environment Feb 2024The versatile capacity of purple phototrophic bacteria (PPB) for producing valuable bioproducts has gathered renewed interest in the field of resource recovery and waste...
The versatile capacity of purple phototrophic bacteria (PPB) for producing valuable bioproducts has gathered renewed interest in the field of resource recovery and waste valorisation. However, greater knowledge regarding the viability of applying PPB technologies in outdoor, large-scale systems is required. This study assessed, for the first time, the upscaling of the phototrophic polyhydroxyalkanoate (PHA) production technology in a pilot-scale system operated in outdoor conditions. An integrated system composed of two up-flow anaerobic sludge blanket (UASB) reactors (for fermentation of wastewater with molasses), and two high-rate algal ponds retrofitted into PPB ponds, was operated in a wastewater treatment plant under outdoor conditions. UASB's adaptation to the outdoor temperatures involved testing different operational settings, namely hydraulic retention times (HRT) of 48 and 72 h, and molasses fermentation in one or two UASBs. Results have shown that the fermentation of molasses in both UASBs with an increased HRT of 72 h was able to ensure a suitable operation during colder conditions, achieving 3.83 ± 0.63 g COD/L, compared to the 3.73 ± 0.85 g COD/L achieved during warmer conditions (molasses fermentation in one UASB; HRT 48 h). Furthermore, the PPB ponds were operated under a light-feast/dark-aerated-famine strategy and fed with the fermented wastewater and molasses from the two UASBs. The best PHA production was obtained during the summer of 2018 and spring of 2019, attaining 34.7 % gPHA/gVSS with a productivity of 0.11 gPHA L day and 36 % gPHA/gVSS with a productivity of 0.14 gPHA L day, respectively. Overall, this study showcases the first translation of phototrophic PHA production technology from an artificially illuminated laboratory scale system into a naturally illuminated, outdoor, pilot-scale system. It also addresses relevant process integration aspects with UASBs for pre-fermenting wastewater with molasses, providing a novel operational strategy to achieve photosynthetic PHA production in outdoor full-scale systems.
Topics: Wastewater; Polyhydroxyalkanoates; Ponds; Sewage; Bacteria; Bioreactors
PubMed: 38029992
DOI: 10.1016/j.scitotenv.2023.168899 -
Ecology and Evolution Nov 2023is a true cave insect living in the dark areas of caves. It has the characteristics of sparse skin pigmentation, degeneration of the compound eyes and monocular eyes,...
is a true cave insect living in the dark areas of caves. It has the characteristics of sparse skin pigmentation, degeneration of the compound eyes and monocular eyes, and obvious preference for high-humidity and low-temperature environments. Given the highly specialized, rare, and limited distribution, is considered an endangered species and also a first-level national protected insect in China. Cave creatures often undergo dramatic morphological changes in their sensory systems to adapt to the cave environment. Most previous studies mainly focused on morphological adaptive changes in cave insects, and only a few studied the changes at the gene level. In this study, we performed transcriptome analysis of and constructed phylogenetic trees of genes that are related to environmental adaptation, including chemosensory, visual-related, reproduction-related, temperature adaptation-related, and winged morph differentiation-related genes. Besides, the expression levels of environmental adaption-related genes in different tissues, including antennae, heads, thoraxes, abdomens, legs, and tails, were analyzed. The results showed the loss of chemosensory genes and vision-related genes, the conservation of reproduction-related genes and temperature adaptation-related genes, and the conservation of wing-related genes despite the loss of wings, and the results were consistent with other cave insects. The identification and expression study of genes possibly related to the environmental adaptability in provided basic data for the protection of this endangered species and increased knowledge about insect evolution in general.
PubMed: 38020696
DOI: 10.1002/ece3.10717 -
Proceedings. Biological Sciences Nov 2023Convergent evolution is widely regarded as a signature of adaptation. However, testing the adaptive consequences of convergent phenotypes is challenging, making it...
Convergent evolution is widely regarded as a signature of adaptation. However, testing the adaptive consequences of convergent phenotypes is challenging, making it difficult to exclude non-adaptive explanations for convergence. Here, we combined feather reflectance spectra and phenotypic trajectory analyses with visual and thermoregulatory modelling to test the adaptive significance of dark plumage in songbirds of the California Channel Islands. By evolving dark dorsal plumage, island birds are generally less conspicuous to visual-hunting raptors in the island environment than mainland birds. Dark dorsal plumage also reduces the energetic demands associated with maintaining homeothermy in the cool island climate. We also found an unexpected pattern of convergence, wherein the most divergent island populations evolved greater reflectance of near-infrared radiation. However, our heat flux models indicate that elevated near-infrared reflectance is not adaptive. Analysis of feather microstructure suggests that mainland-island differences are related to coloration of feather barbs and barbules rather than their structure. Our results indicate that adaptive and non-adaptive mechanisms interact to drive plumage evolution in this system. This study sheds light on the mechanisms driving the association between dark colour and wet, cold environments across the tree of life, especially in island birds.
Topics: Animals; Songbirds; Feathers; Phenotype; Body Temperature Regulation; Channel Islands; Pigmentation; Islands
PubMed: 37964520
DOI: 10.1098/rspb.2023.1914 -
Graefe's Archive For Clinical and... Jun 2024Visual function is a complex process in which external visual stimuli are interpreted. Patients with retinal diseases and prolonged follow-up times may experience... (Review)
Review
PURPOSE
Visual function is a complex process in which external visual stimuli are interpreted. Patients with retinal diseases and prolonged follow-up times may experience changes in their visual function that are not detected by the standard visual acuity measure, as they are a result of other alterations in visual function. With the advancement of different methods to evaluate visual function, additional measurements have become available, and further standardization suggests that some methods may be promising for use in clinical trials or routine clinical practice. The objectives of this article are to review these additional measurements and to provide guidance on their application.
METHODS
The Vision Academy's membership of international retinal disease experts reviewed the literature and developed consensus recommendations for the application of additional measures of visual function in routine clinical practice or clinical trials.
RESULTS
Measures such as low-luminance visual acuity, contrast sensitivity, retinal fixation and microperimetry, and reading performance are measures which can complement visual acuity measurements to provide an assessment of overall visual function, including impact on patients' quality of life. Measures such as dark adaptation, color vision testing, binocular vision testing, visual recognition testing, and shape discrimination require further optimization and validation before they can be implemented in everyday clinical practice.
CONCLUSION
Additional measurements of visual function may help identify patients who could benefit from earlier diagnosis, detection of disease progression, and therapeutic intervention. New and additional functional clinical trial endpoints are required to fully understand the early stages of macular disease, its progression, and the response to treatment.
Topics: Humans; Visual Acuity; Contrast Sensitivity; Macula Lutea; Retinal Diseases; Vision Tests; Dark Adaptation; Visual Field Tests; Quality of Life
PubMed: 37938378
DOI: 10.1007/s00417-023-06272-1