GmEID1 modulates light signaling through the Evening Complex to control flowering time and yield in soybean.

Soybean (Glycine max) morphogenesis and flowering time are accurately regulated by photoperiod, which determine the yield potential and limit soybean cultivars to a narrow latitudinal range. The E3 and E4 genes, which encode phytochrome A photoreceptors in soybean, promote the expression of the legume-specific flowering repressor E1 to delay floral transition under long-day (LD) conditions. However, the underlying molecular mechanism remains unclear. Here, we show that the diurnal expression pattern of GmEID1 is opposite to that of E1 and targeted mutations in the GmEID1 gene delay soybean flowering regardless of daylength. GmEID1 interacts with J, a key component of circadian Evening Complex (EC), to inhibit E1 transcription. Photoactivated E3/E4 interacts with GmEID1 to inhibit GmEID1-J interaction, promoting J degradation resulting in a negative correlation between daylength and the level of J protein. Notably, targeted mutations in GmEID1 improved soybean adaptability by enhancing yield per plant up to 55.3% compared to WT in field trials performed in a broad latitudinal span of more than 24°. Together, this study reveals a unique mechanism in which E3/E4-GmEID1-EC module controls flowering time and provides an effective strategy to improve soybean adaptability and production for molecular breeding.

The evening complex integrates photoperiod signals to control flowering in rice.

Plants use photoperiodism to activate flowering in response to a particular daylength. In rice, flowering is accelerated in short-day conditions, and even a brief exposure to light during the dark period (night-break) is sufficient to delay flowering. Although many of the genes involved in controlling flowering in rice have been uncovered, how the long- and short-day flowering pathways are integrated, and the mechanism of photoperiod perception is not understood. While many of the signaling components controlling photoperiod-activated flowering are conserved between Arabidopsis and rice, flowering in these two systems is activated by opposite photoperiods. Here we establish that photoperiodism in rice is controlled by the evening complex (EC). We show that mutants in the EC genes LUX ARRYTHMO (LUX) and EARLY FLOWERING3 (ELF3) paralogs abolish rice flowering. We also show that the EC directly binds and suppresses the expression of flowering repressors, including PRR37 and Ghd7. We further demonstrate that light acts via phyB to cause a rapid and sustained posttranslational modification of ELF3-1. Our results suggest a mechanism by which the EC is able to control both long- and short-day flowering pathways.

Evening prolonged relatively low melanopic equivalent daylight illuminance light exposure increases arousal before and during sleep without altering sleep structure.

Light can influence many psychophysiological functions beyond vision, including alertness, circadian rhythm, and sleep, namely the non-image forming (NIF) effects of light. Melanopic equivalent daylight illuminance (mel-EDI) is currently recommended as the predictor of the NIF effects of light. Although light dose is also critical for entraining and regulating circadian cycle, it is still unknown whether relatively low mel-EDI light exposure for prolonged duration in the evening would affect pre-sleep arousal and subsequent sleep. In all, 18 healthy college students (10 females, mean [standard deviation] age 21.67 [2.03] years) underwent 2 experimental nights with a 1 week interval in a simulated bedroom environment. During experimental nights, participants were either exposed to high or low mel-EDI light (73 versus 38 lx mel-EDI, 90 versus 87 photopic lx at eye level, 150 photopic lx at table level) for 3.5 h before regular bedtime, and their sleep was monitored by polysomnography. Subjective sleepiness, mood, and resting-state electroencephalography during light exposure were also investigated. Results showed no significant differences in sleep structure and sleep quality between the two light conditions, whereas 3.5 h of exposure to high versus low mel-EDI light induced marginally higher physiological arousal in terms of a lower delta but higher beta power density before sleep, as well as a lower delta power density during sleep. Moreover, participants felt happier before sleep under exposure to high versus low mel-EDI light. These findings together with the current literature suggest that evening prolonged relatively low mel-EDI light exposure may mildly increase arousal before and during sleep but affected sleep structure less.

Greater sensitivity of the circadian system of women to bright light, but not dim-to-moderate light.

Women typically sleep and wake earlier than men and have been shown to have earlier circadian timing relative to the light/dark cycle that synchronizes the clock. A potential mechanism for earlier timing in women is an altered response of the circadian system to evening light. We characterized individual-level dose-response curves for light-induced melatonin suppression using a within-subjects protocol. Fifty-six participants (29 women, 27 men; aged 18-30 years) were exposed to a range of light illuminances (10, 30, 50, 100, 200, 400, and 2000 lux) using melatonin suppression relative to a dim control (<1 lux) as a marker of light sensitivity. Women were free from hormonal contraception. To examine the potential influence of sex hormones, estradiol and progesterone was examined in women and testosterone was examined in a subset of men. Menstrual phase was monitored using self-reports and estradiol and progesterone levels. Women exhibited significantly greater melatonin suppression than men under the 400-lux and 2000-lux conditions, but not under lower light conditions (10-200 lux). Light sensitivity did not differ by menstrual phase, nor was it associated with levels of estradiol, progesterone, or testosterone, suggesting the sex differences in light sensitivity were not acutely driven by circulating levels of sex hormones. These results suggest that sex differences in circadian timing are not due to differences in the response to dim/moderate light exposures typically experienced in the evening. The finding of increased bright light sensitivity in women suggests that sex differences in circadian timing could plausibly instead be driven by a greater sensitivity to phase-advancing effects of bright morning light.

The association between diet quality and chrononutritional patterns in young adults.

PURPOSE: Young adults eat erratically and later in the day which may impact weight and cardiometabolic health. This cross-sectional study examined relationships between chrononutritional patterns and diet quality in two young adult populations: a university and community sample. METHODS: Three days of dietary data were collected including food images captured using wearable cameras. Chrononutritional variables were extracted: time of first and last eating occasions, caloric midpoint (time at which 50% of daily energy was consumed), number of eating occasions per day, eating window, day-to-day variability of the above metrics, and evening eating (≥20:00h). The Healthy Eating Index for Australian Adults scored diet quality. Statistical analyses controlled for gender, body mass index, and socio-economic status. RESULTS: No significant associations between chrononutritional patterns and diet quality were found for all participants (n = 95). However, differences in diet quality were found between university (n = 54) and community (n = 41) samples with average diet quality scores of 59.1 (SD 9.7) and 47.3 (SD 14.4), respectively. Of those who extended eating ≥20:00 h, university participants had better diet quality (62.9±SE 2.5 vs. 44.3±SE 2.3, p < 0.001) and discretionary scores (7.9±SE 0.9 vs. 1.6±SE 0.6, p < 0.001) than community participants. University participants consumed predominately healthful dinners and fruit ≥20:00h whereas community participants consumed predominately discretionary foods. CONCLUSION: For the general young adult population, meal timing needs to be considered. Food choices made by this cohort may be poorer during evenings when the desire for energy-dense nutrient-poor foods is stronger. However, meal timing may be less relevant for young adults who already engage in healthy dietary patterns.

A critical role of the soybean evening complex in the control of photoperiod sensitivity and adaptation.

Photoperiod sensitivity is a key factor in plant adaptation and crop production. In the short-day plant soybean, adaptation to low latitude environments is provided by mutations at the J locus, which confer extended flowering phase and thereby improve yield. The identity of J as an ortholog of Arabidopsis ELF3, a component of the circadian evening complex (EC), implies that orthologs of other EC components may have similar roles. Here we show that the two soybean homeologs of LUX ARRYTHMO interact with J to form a soybean EC. Characterization of mutants reveals that these genes are highly redundant in function but together are critical for flowering under short day, where the lux1 lux2 double mutant shows extremely late flowering and a massively extended flowering phase. This phenotype exceeds that of any soybean flowering mutant reported to date, and is strongly reminiscent of the "Maryland Mammoth" tobacco mutant that featured in the seminal 1920 study of plant photoperiodism by Garner and Allard [W. W. Garner, H. A. Allard, J. Agric. Res. 18, 553-606 (1920)]. We further demonstrate that the J-LUX complex suppresses transcription of the key flowering repressor E1 and its two homologs via LUX binding sites in their promoters. These results indicate that the EC-E1 interaction has a central role in soybean photoperiod sensitivity, a phenomenon also first described by Garner and Allard. EC and E1 family genes may therefore constitute key targets for customized breeding of soybean varieties with precise flowering time adaptation, either by introgression of natural variation or generation of new mutants by gene editing.

Dim light in the evening causes coordinated realignment of circadian rhythms, sleep, and short-term memory.

Light provides the primary signal for entraining circadian rhythms to the day/night cycle. In addition to rods and cones, the retina contains a small population of photosensitive retinal ganglion cells (pRGCs) expressing the photopigment melanopsin (OPN4). Concerns have been raised that exposure to dim artificial lighting in the evening (DLE) may perturb circadian rhythms and sleep patterns, and OPN4 is presumed to mediate these effects. Here, we examine the effects of 4-h, 20-lux DLE on circadian physiology and behavior in mice and the role of OPN4 in these responses. We show that 2 wk of DLE induces a phase delay of ∼2 to 3 h in mice, comparable to that reported in humans. DLE-induced phase shifts are unaffected in Opn4-/- mice, indicating that rods and cones are capable of driving these responses in the absence of melanopsin. DLE delays molecular clock rhythms in the heart, liver, adrenal gland, and dorsal hippocampus. It also reverses short-term recognition memory performance, which is associated with changes in preceding sleep history. In addition, DLE modifies patterns of hypothalamic and cortical cFos signals, a molecular correlate of recent neuronal activity. Together, our data show that DLE causes coordinated realignment of circadian rhythms, sleep patterns, and short-term memory process in mice. These effects are particularly relevant as DLE conditions-due to artificial light exposure-are experienced by the majority of the populace on a daily basis.

Evolution and seed dormancy shape plant genotypic structure through a successional cycle.

Dormancy has repeatedly evolved in plants, animals, and microbes and is hypothesized to facilitate persistence in the face of environmental change. Yet previous experiments have not tracked demography and trait evolution spanning a full successional cycle to ask whether early bouts of natural selection are later reinforced or erased during periods of population dormancy. In addition, it is unclear how well short-term measures of fitness predict long-term genotypic success for species with dormancy. Here, we address these issues using experimental field populations of the plant Oenothera biennis, which evolved over five generations in plots exposed to or protected from insect herbivory. While populations existed above ground, there was rapid evolution of defensive and life-history traits, but populations lost genetic diversity and crashed as succession proceeded. After >5 y of seed dormancy, we triggered germination from the seedbank and genotyped >3,000 colonizers. Resurrected populations showed restored genetic diversity that reduced earlier responses to selection and pushed population phenotypes toward the starting conditions of a decade earlier. Nonetheless, four defense and life-history traits remained differentiated in populations with insect suppression compared with controls. These findings capture key missing elements of evolution during ecological cycles and demonstrate the impact of dormancy on future evolutionary responses to environmental change.

Oenothera biennis with strong copper toxicity resistance enriches trace copper in seeds under copper pollution soil.

Excess copper (Cu) imparts negative effects on plant growth and productivity in soil. To develop the ability of O. biennis to govern pollution soil containing excessive Cu, we investigated seed germination, seedling growth, and seed yield. Furthermore, Cu content and the expression levels of Cu transport related genes in different tissues were measured under exogenous high concentration Cu. O. biennis seeds were sensitive to excess Cu, with an observed reduction in the germination rate, primary root length, fresh weight, and number of seeds germinated daily. Consecutive Cu stress did not cause fatal damage to evening primrose, yet it slowed down plant growth slightly by reducing the leaf water, chlorophyll, plant yield, and seed oil contents while increasing the soluble sugar, proline, malondialdehyde, and H2O2 contents. The Cu content in different organs of O. biennis was disrupted by excess Cu. In particular, the Cu content in O. biennis seeds and seed oil increased and subsequently decreased with the increase of exogenous Cu, reaching a peak under 600 mg·kg-1 consecutive Cu. Furthermore, the 4-month 900 mg·kg-1 Cu treatment did not induce the excessive accumulation of Cu in peels, seeds, and seed oil, maintaining the Cu content within the range required by the Chinese National Food Safety Standards. The treatment also resulted in an upregulation of Cu-uptake (ObCOPT5, ObZIP4, and ObYSL2) and vigorous efflux (ObHMA1) of transport genes, of which expression levels were significant positive correlation (p < 0.05) with the Cu content. Among all organs, the stem replaced the root as the organ exhibited the greatest ability to absorb and store Cu, and even the Cu transport genes could still function continuously in stem under excess Cu. This work identified a species that can tolerate high Cu content in soil while maintaining a high yield. Furthermore, the results revealed the enrichment of Cu to occur primarily in the O. biennis stem rather than the seeds and peel under excess Cu.

Co-Processed Crystalline Solids of Ivermectin with Span® 60 as Solubility Enhancers of Ivermectin in Natural Oils.

Despite being discovered over five decades ago, little is still known about ivermectin. Ivermectin has several physico-chemical properties that can result in it having poor bioavailability. In this study, polymorphic and co-crystal screening was used to see if such solid-state modifications can improve the oil solubility of ivermectin. Span® 60, a lipophilic non-ionic surfactant, was chosen as co-former. The rationale behind attempting to improve oil solubility was to use ivermectin in future topical and transdermal preparations to treat a range of skin conditions like scabies and head lice. Physical mixtures were also prepared in the same molar ratios as the co-crystal candidates, to serve as controls. Solid-state characterization was performed using X-ray powder diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The FTIR spectra of the co-crystal candidates showed the presence of Span® 60's alkyl chain peaks, which were absent in the spectra of the physical mixtures. Due to the absence of single-crystal X-ray data, co-crystal formation could not be confirmed, and therefore these co-crystal candidates were referred to as co-processed crystalline solids. Following characterization, the solid-state forms, physical mixtures and ivermectin raw material were dissolved in natural penetration enhancers, i.e., avocado oil (AVO) and evening primrose oil (EPO). The co-processed solids showed increased oil solubility by up to 169% compared to ivermectin raw material. The results suggest that co-processing of ivermectin with Span® 60 can be used to increase its oil solubility and can be useful in the development of oil-based drug formulations.

Circadian regulation of the GLYCINE-RICH RNA-BINDING PROTEIN gene by the master clock protein CIRCADIAN CLOCK-ASSOCIATED 1 is important for plant innate immunity.

Recent studies have demonstrated the importance of temporal regulation of pathogen defense by the circadian clock. However, our understanding of the molecular basis underlying this role of the circadian clock is still in its infancy. We report here the mechanism by which the Arabidopsis master clock protein CCA1 regulates an output target gene GRP7 for its circadian expression and function in pathogen defense. Our data firmly establish that CCA1 physically associates with the GRP7 promoter via the predicted CCA1-binding motif, evening element (EE). A site-directed mutagenesis study showed that while individual EE motifs differentially contribute to robust circadian expression of GRP7, abolishing all four EE motifs in the proximal GRP7 promoter disrupts rhythmicity of GRP7 expression and results in misalignment of defense signaling mediated by GRP7 and altered pathogen responses. This study provides a mechanistic link of the circadian regulation of an output gene to its biological function in pathogen defense, underscoring the importance of temporal control of plant innate immunity.

On the origin and evolution of the dual oscillator model underlying the photoperiodic clockwork in the suprachiasmatic nucleus.

Decades have now passed since Colin Pittendrigh first proposed a model of a circadian clock composed of two coupled oscillators, individually responsive to the rising and setting sun, as a flexible solution to the challenge of behavioral and physiological adaptation to the changing seasons. The elegance and predictive power of this postulation has stimulated laboratories around the world in searches to identify and localize such hypothesized evening and morning oscillators, or sets of oscillators, in insects, rodents, and humans, with experimental designs and approaches keeping pace over the years with technological advances in biology and neuroscience. Here, we recount the conceptual origin and highlight the subsequent evolution of this dual oscillator model for the circadian clock in the mammalian suprachiasmatic nucleus; and how, despite our increasingly sophisticated view of this multicellular pacemaker, Pittendrigh's binary conception has remained influential in our clock models and metaphors.

A clock for all seasons in the subterranean.

In 1976, Pittendrigh and Daan established a theoretical framework which has coordinated research on circadian clock entrainment and photoperiodism until today. The "wild clocks" approach, which concerns studying wild species in their natural habitats, has served to test their models, add new insights, and open new directions of research. Here, we review an integrated laboratory, field and modeling work conducted with subterranean rodents (Ctenomys sp.) living under an extreme pattern of natural daily light exposure. Tracking animal movement and light exposure with biologgers across seasons and performing laboratory experiments on running-wheel cages, we uncovered the mechanisms of day/night entrainment of the clock and of photoperiodic time measurement in this subterranean organism. We confirmed most of the features of Pittendrigh and Daan's models but highlighted the importance of integrating them with ecophysiological techniques, methodologies, and theories to get a full picture of the clock in the wild. This integration is essential to fully establish the importance of the temporal dimension in ecological studies and tackling relevant questions such as the role of the clock for all seasons in a changing planet.

Report from a randomized control trial: improved alignment between circadian biology and sleep-wake behavior as a mechanism of depression symptom improvement in evening-type adolescents with depressive symptoms.

STUDY OBJECTIVES: An evening circadian preference is common among adolescents. It is characterized by a behavioral predilection for later sleep and wake timing and is associated with higher rates of Major Depressive Disorder (MDD). The present study aims to (a) test the effectiveness of a cognitive behavioral sleep intervention (Transdiagnostic Sleep and Circadian Intervention; TranS-C) in a sample of adolescents with an evening circadian preference and clinically significant depressive symptoms and (b) evaluate improved alignment between circadian biology and sleep-wake behavior as a potential mechanism in the relationship between sleep and depression symptom improvement. METHODS: Adolescents with an evening circadian preference and clinically significant depressive symptoms were randomized to receive TranS-C (n = 24) or a psychoeducation condition (PE; n = 18). Alignment between circadian biology and sleep-wake behavior was measured using objective biological measurement. Measures of sleep and circadian rhythm were taken at pre- and posttreatment, and depression symptoms were measured at pre- and posttreatment and 6- and 12-month follow-up. RESULTS: Mixed effects modeling revealed that compared with an active control condition, TranS-C resulted in a significant reduction in MDD severity at 12-month follow-up. A MacArthur mediation analysis conducted to explore alignment between circadian biology and sleep-wake behavior as a mediator of depression severity reduction through 12-month follow-up revealed a significant interaction between change in alignment between circadian biology and sleep-wake behavior and treatment arm, indicating that improved alignment between circadian biology and sleep-wake behavior at posttreatment was associated with improvements in depression outcomes at 12-month follow-up under the treatment condition. CONCLUSIONS: These results provide novel evidence for improved alignment between circadian biology and sleep-wake behavior as a specific mechanism of depression improvement, provide key clues into the complex relationship between sleep and depression, and have significant clinical implications for adolescents with depression.

Circadian aspects in the aetiology and pathophysiology of insomnia.

Because the endogenous circadian pacemaker is a very strong determinant of alertness/sleep propensity across the 24 h period, its mistiming may contribute to symptoms of insomnia (e.g., difficulties initiating sleep and maintaining sleep) and to the development of insomnia disorder. Despite the separation of insomnia and circadian rhythm disorders in diagnostic nosology implying independent pathophysiology, there is considerable evidence of co-morbidity and interaction between them. Sleep onset insomnia is associated with later timed circadian rhythms and can be treated with morning bright light to shift rhythms to an earlier timing. It is also possible that the causal link may go in both directions and that having a delayed circadian rhythm can result in enough experiences of delayed sleep onset to lead to some conditioned insomnia or insomnia disorder further exacerbating a delayed circadian rhythm. Early morning awakening insomnia is associated with an advanced circadian phase (early timing) and can be treated with evening bright light resulting in a delay of rhythms and an improved ability to sleep later in the morning and to obtain more sleep. There is some evidence suggesting that sleep maintenance insomnia is associated with a blunted amplitude of circadian rhythm that may be treated with increased regularity of sleep and light exposure timing. However, this is an insomnia phenotype that requires considerably more circadian research as well as further insomnia clinical research with the other insomnia phenotypes incorporating circadian timing measures and treatments.

A micro-randomized pilot study to examine the impact of just-in-time nudging on after-dinner snacking in adults with type 2 diabetes: A study protocol.

AIM: To determine whether a digital nudge soon after dinner reduces after-dinner snacking events as measured objectively by continuous glucose monitoring (CGM) in patients with type 2 diabetes (T2D). METHODS: This is a single-site micro-randomized trial (MRT). People with T2D, aged 18-75 years, managed with diet or a stable dose of oral antidiabetic medications for at least 3 months, and who habitual snack after dinner at least 3 nights per week, will be recruited. Picto-graphic nudges were designed by mixed research methods. After a 2-week lead-in phase to determine eligibility and snacking behaviours by a CGM detection algorithm developed by the investigators, participants will be micro-randomized daily (1:1) to a second 2-week period to either a picto-graphic nudge delivered-in-time (Intui Research) or no nudge. During lead-in and MRT phases, 24-hour glucose will be measured by CGM, sleep will be tracked by an under-mattress sleep sensor, and dinner timing will be captured daily by photographing the evening meal. RESULTS: The primary outcome is the difference in the incremental area under the CGM curve between nudging and non-nudging days during the period from 90 minutes after dinner until 04:00 AM. Secondary outcomes include the effect of baseline characteristics on treatment, and comparisons of glucose peaks and time-in-range between nudging and non-nudging days. The feasibility of 'just-in-time' messaging and nudge acceptability will be evaluated, along with the analysis of sleep quality measures and their night-to-night variability. CONCLUSIONS: This study will provide preliminary evidence of the impact of appropriately timed digital nudges on 24 -hour intertitial glucose levels resulting from altered after-dinner snacking in people with T2D. An exploratory sleep substudy will provide evidence of a bidirectional relationship between after-dinner snacking behaviour, glycaemia and sleep. Ultimately, this study will allow for the design of a future confirmatory study of the potential for digital nudging to improve health related behaviours and health outcomes.

Effect of timing of administration on lipid-lowering efficacy of statins-meta-analysis.

BACKGROUND: To investigate the effect of timing of statin administration on lipid-lowering efficacy. METHODS: Computer searches of Pubmed, Embase, Cochrane Library, and Web of Science databases from 1986 to 2023. The impact of administration time on the lipid-lowering efficacy of statin drugs was investigated. Following a series of screenings, a funnel plot was constructed to assess its symmetry, and Egger and Beggar tests were conducted using StataMP-64 to evaluate publication bias. Meta-analysis was performed using RevMan 5.3 to combine MD values. RESULTS: Fifteen papers (1352 participants) met and included the criteria. The results of the meta-analysis showed that the effect of morning and evening administration time on plasma triglycerides (TG) (P > 0.05) and plasma high-density lipoprotein cholesterol (HDL-C) (P > 0.05) was not statistically significant. There were significant reductions in total cholesterol (TC) (MD: 0.15 mmol/L, 95% CI: 0.06-0.23, P < 0.01) and low-density lipoprotein cholesterol (LDL-C) (MD: 0.10 mmol/L, 95% CI: - 0.00-0.20, P < 0.01) in the night group. According to the analysis results of the half-life of statins, only short half-life statins showed that nocturnal administration reduced LDL-C (MD: 0.21 mmol/L, 95% CI: 0.09-0.33, P < 0.01) and TC (MD: 0.32 mmol/L, 95% CI: 0.18-0.46, P < 0.01) levels and was better than morning administration. Long half-life statins did not show significant differences. In addition, the administration time of short half-life statins also showed that night administration tended to reduce TG (MD: 0.16 mmol/L, 95% CI: 0.02-0.30, P < 0.05) levels. In subgroup analysis according to clinical factors in patients aged < 55 years, there was no significant difference in the timing of administration between the two groups; the efficacy of statins in lowering lipids in patients aged ≥ 55 years was significantly different in the TC group (P < 0.01) and LDL-C group (P < 0.01). The administration time of the TC group (P < 0.05) and LDL-C group (P < 0.05) in the Americas, Europe, and Asian groups was significantly different for statins. In addition, the American group also showed that the administration time of the two groups was significantly different from the TG group (P < 0.05). CONCLUSION: The efficacy of administering short half-life statin drugs at night in reducing plasma levels of TC, LDL-C, and TG surpasses that of morning administration. However, this study did not determine the impact of timing of statin administration in patients taking long half-life statins on the efficacy of the medication. Therefore, it is recommended to consider patient adherence when. The study was registered on PROSPERO (International Prospective Register of Systematic Reviews) as CRD42022372105 (available at https://www.crd.york.ac.uk/prospero/ ).

Molecular mechanisms of Evening Complex activity in Arabidopsis.

The Evening Complex (EC), composed of the DNA binding protein LUX ARRHYTHMO (LUX) and two additional proteins EARLY FLOWERING 3 (ELF3) and ELF4, is a transcriptional repressor complex and a core component of the plant circadian clock. In addition to maintaining oscillations in clock gene expression, the EC also participates in temperature and light entrainment, acting as an important environmental sensor and conveying this information to growth and developmental pathways. However, the molecular basis for EC DNA binding specificity and temperature-dependent activity were not known. Here, we solved the structure of the DNA binding domain of LUX in complex with DNA. Residues critical for high-affinity binding and direct base readout were determined and tested via site-directed mutagenesis in vitro and in vivo. Using extensive in vitro DNA binding assays of LUX alone and in complex with ELF3 and ELF4, we demonstrate that, while LUX alone binds DNA with high affinity, the LUX-ELF3 complex is a relatively poor binder of DNA. ELF4 restores binding to the complex. In vitro, the full EC is able to act as a direct thermosensor, with stronger DNA binding at 4 °C and weaker binding at 27 °C. In addition, an excess of ELF4 is able to restore EC binding even at 27 °C. Taken together, these data suggest that ELF4 is a key modulator of thermosensitive EC activity.

Activities and social contact as antecedents to sleep onset time in U.S. adolescents.

This study evaluated adolescents' evening patterns in activities, social contact, and location to better understand antecedents to adolescents' sleep onset time (SOT). The SOT is important for sleep duration and related health outcomes. Using a nationally representative sample of 15- to 18-year-old adolescents from the American Time Use Survey (N = 10,341; 47% female; 57% white), structural equation modeling demonstrated that late SOTs mediated links between evening activities, social contact, locations, and shorter sleep durations. Passive leisure, time in public locations, and time with friends late in the evenings were associated with later SOTs, whereas homework and active leisure did not. Parents and practitioners can use this information to carefully evaluate evening activities, social contact, and location to support healthy SOTs for adolescents across time.

Evening primrose oil attenuates oxidative stress, inflammation, fibrosis, apoptosis, and ultrastructural alterations induced by metanil yellow in the liver of rat: a histological, immunohistochemical, and biochemical study.

The food color metanil yellow (Myl) is hazardous to several body systems. Evening primrose oil (EPO) was reported to have anti-inflammatory and anti-oxidant properties. The present work investigated the impact of Myl on the hepatic structure and function of rats and evaluated the protective effect of EPO. Forty adult male rats were divided into four groups: control, EPO (5 g/kg/day), Myl (200 mg/kg/day), and EPO- Myl group. Myl significantly increased liver enzymes, advanced glycation end products (AGE), oxidative stress parameters, pro-inflammatory cytokines, nuclear factor kappa B (NF-κB), and inducible nitric oxide synthase (iNOS). Blood vessels in the liver were dilated and congested, with cellular infiltration around them and associated with fibrosis. The hepatocytes were vacuolated and had dark nuclei. The immunohistochemical expression of iNOS, glial fibrillary acidic protein (GFAP), and Bax was significantly elevated. Ultrastructurally, the hepatocytes showed lipid droplets, irregular condensed nuclei with widened perinuclear space, dilated rER, mitochondria with destructed cristae, and multiple vacuoles. Dilated congested blood sinusoids and collagen fiber bundles were seen between hepatocytes. Interestingly, these alterations were less pronounced in rats co-administrated with EPO and Myl. In conclusion, EPO can protect liver against the toxic effects of Myl due to its anti-inflammatory and anti-oxidant activities.