Chloroplast biogenesis is dependent on master regulators from the GOLDEN2-LIKE (GLK) family of transcription factors. However, glk mutants contain residual chlorophyll, indicating that other proteins must be involved. Here, we identify MYB-related transcription factors as regulators of chloroplast biogenesis in the liverwort Marchantia polymorpha and angiosperm Arabidopsis thaliana.
View Article and Find Full Text PDFCryopreserved human heart valves fill a crucial role in the treatment for congenital cardiac anomalies, since the use of alternative mechanical and xenogeneic tissue valves have historically been limited in babies. Heart valve models have been used since 1998 to better understand the impact of cryopreservation variables on the heart valve tissue components with the ultimate goals of improving cryopreserved tissue outcomes and potentially extrapolating results with tissues to organs. Cryopreservation traditionally relies on conventional freezing, employing cryoprotective agents, and slow cooling to sub-zero centigrade temperatures; but it is plagued by the formation of ice crystals and cell damage upon thawing.
View Article and Find Full Text PDFLegionnaires' disease is an atypical pneumonia caused by Legionella pneumophila ( pneumonia that features slow onset, nonproductive cough, fatigue, headache, sore throat, myalgias, and malaise. It can be difficult to diagnose, as it presents with extrapulmonary symptoms, and delay in treatment can be fatal. Here, we present the case of a previously healthy 32-year-old Caucasian male with Legionnaires disease who only presented to the clinic with abdominal pain and diarrhea.
View Article and Find Full Text PDFMaternal mortality continues to rise in the United States and disproportionately affects those in Alabama. Lack of patient education on warning signs is a preventable cause of maternal mortality. This article aims to systematically quantify existing research investigating the effect of patient education on maternal outcomes.
View Article and Find Full Text PDFCompared with the ancestral C3 state, C4 photosynthesis occurs at higher rates with improved water and nitrogen use efficiencies. In both C3 and C4 plants, rates of photosynthesis increase with light intensity and are maximal around midday. We determined that in the absence of light or temperature fluctuations, photosynthesis in maize (Zea mays) peaks in the middle of the subjective photoperiod.
View Article and Find Full Text PDFC photosynthesis has evolved by repurposing enzymes found in C plants. Compared with the ancestral C state, accumulation of C cycle proteins is enhanced. We used de-etiolation of C and C to understand this process.
View Article and Find Full Text PDFLeaves of shade-avoiding plants such as Arabidopsis (Arabidopsis thaliana) change their growth pattern and position in response to low red to far-red ratios (LRFRs) encountered in dense plant communities. Under LRFR, transcription factors of the phytochrome-interacting factor (PIF) family are derepressed. PIFs induce auxin production, which is required for promoting leaf hyponasty, thereby favoring access to unfiltered sunlight.
View Article and Find Full Text PDFIn C plants, the enzymatic machinery underpinning photosynthesis can vary, with, for example, three distinct C acid decarboxylases being used to release CO in the vicinity of RuBisCO. For decades, these decarboxylases have been used to classify C species into three biochemical sub-types. However, more recently, the notion that C species mix and match C acid decarboxylases has increased in popularity, and as a consequence, the validity of specific biochemical sub-types has been questioned.
View Article and Find Full Text PDFVirtual Reality (VR) experienced through head-mounted displays often leads to vection, discomfort and sway in the user. This study investigated the effect of motion direction and eccentricity on these three phenomena using optic flow patterns displayed using the Valve Index. Visual motion stimuli were presented in the centre, periphery or far periphery and moved either in depth (back and forth) or laterally (left and right).
View Article and Find Full Text PDFC photosynthesis evolved repeatedly from the ancestral C state, improving photosynthetic efficiency by ~50%. In most C lineages, photosynthesis is compartmented between mesophyll and bundle sheath cells, but how gene expression is restricted to these cell types is poorly understood. Using the C model Arabidopsis thaliana, we identified cis-elements and transcription factors driving expression in bundle sheath strands.
View Article and Find Full Text PDFBinary expression systems like the LexA-LexAop system provide a powerful experimental tool kit to study gene and tissue function in developmental biology, neurobiology, and physiology. However, the number of well-defined LexA enhancer trap insertions remains limited. In this study, we present the molecular characterization and initial tissue expression analysis of nearly 100 novel StanEx LexA enhancer traps, derived from the index line.
View Article and Find Full Text PDFPrey animals have evolved a wide variety of behaviours to combat the threat of predation, and these have been generally well studied. However, one of the most common and taxonomically widespread antipredator behaviours of all has, remarkably, received almost no experimental attention: so-called 'protean' behaviour. This is behaviour that is sufficiently unpredictable to prevent a predator anticipating in detail the future position or actions of its prey.
View Article and Find Full Text PDFTemperature is a key environmental variable influencing plant growth and survival. Protection against high temperature stress in eukaryotes is coordinated by heat shock factors (HSFs), transcription factors that activate the expression of protective chaperones such as HEAT SHOCK PROTEIN 70 (HSP70); however, the pathway by which temperature is sensed and integrated with other environmental signals into adaptive responses is not well understood. Plants are exposed to considerable diurnal variation in temperature, and we have found that there is diurnal variation in thermotolerance in Arabidopsis thaliana, with maximal thermotolerance coinciding with higher HSP70 expression during the day.
View Article and Find Full Text PDFCertain striped patterns can induce illusory motion, such as those used in op-art. The visual system and the vestibular system work together closely, and so it is possible that illusory motion from a visual stimulus can result in uncertainty in the vestibular system. This increased uncertainty may be measureable in terms of the magnitude of head movements.
View Article and Find Full Text PDFPlants have significantly more transcription factor (TF) families than animals and fungi, and plant TF families tend to contain more genes; these expansions are linked to adaptation to environmental stressors. Many TF family members bind to similar or identical sequence motifs, such as G-boxes (CACGTG), so it is difficult to predict regulatory relationships. We determined that the flanking sequences near G-boxes help determine in vitro specificity but that this is insufficient to predict the transcription pattern of genes near G-boxes.
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