Dehydration Research Articles

Collagen XIII Is the Key Molecule of Neurovascular Junctions in the Neuroendocrine System

Introduction: Axons of magnocellular neurosecretory cells project from the hypothalamus to the posterior lobe (PL) of the pituitary. In the PL, a wide perivascular space exists between the outer basement membrane (BM), where nerve axons terminate, and the inner BM lining the fenestrated capillaries. Hypothalamic axon terminals and outer BMs in the PL form neurovascular junctions. We previously had found that collagen XIII is strongly localized in the outer BMs. In this study, we investigated the role of collagen XIII in the PL of rat pituitaries. Methods: We first studied the expression of Col13a1, the gene encoding the α1 chains of collagen XIII, in rat pituitaries via quantitative real-time polymerase chain reaction and in situ hybridization. We observed the distribution of COL13A1 in the rat pituitary using immunohistochemistry and immunoelectron microscopy. We examined the expression of Col13a1 and the distribution of COL13A1 during the development of the pituitary. In addition, we examined the effects of water deprivation and arginine vasopressin (AVP) signaling on the expression of Col13a1 in the PL. Results: Col13a1 was expressed in NG2-positive pericytes, and COL13A1 signals were localized in the outer BM of the PL. The expression of Col13a1 was increased by water deprivation and was regulated via the AVP/AVPR1A/Gαq/11 cascade in pericytes of the PL. Conclusion: These results suggest that pericytes surrounding fenestrated capillaries in the PL secrete COL13A1 and are involved in the construction of neurovascular junctions. COL13A1 is localized in the outer BM surrounding capillaries in the PL and may be involved in the connection between capillaries and axon terminals.

Hydration status and biochemical profile of Quarter Horses in vaquejada training

The hydration status and biochemical profile were assessed and compared in two Quarter Horses groups (pull and helper), at three times (T) of a vaquejada training: at rest, before exercise (T0); after three sprints or races (T1); after an hour of rest from sprints (T2). There was no significant difference between the evaluation times in each group nor between the groups in the times evaluated for the parameters: capillary refill time, skin turgor, color and humidity of the mucosa, total plasma proteins, creatinine, urea and osmolarity, creatine kinase, aspartate aminotransferase, total calcium, phosphorus, and total magnesium. There was increase in the hematocrit and plasma glucose in both groups at T1, but without differences among the groups. The plasm lactate increased in T1. Only for plasma lactate there were changes between the groups, being higher in the pull at T1. It was concluded that, in response to the imposed exercise, the pull and helper groups showed similar hydration status with only slight dehydration, and maintained their biochemical rates preserved, except lactatemia which increased in both, but higher in the pull, suggesting that this group performs more intense anerobic metabolism in the vaquejada.

Characterization of carboxylated cellulose nanofibrils and oligosaccharides from Kraft pulp fibers and their potential elicitor effect on the gene expression of Capsicum annuum

Biomass-derived oligo- and polysaccharides may act as elicitors, i.e., bioactive molecules that trigger plant immune responses. This is particularly important to increase the resistance of plants to abiotic and biotic stresses. In this study, cellulose nanofibrils (CNF) gels were obtained by TEMPO-mediated oxidation of unbleached and bleached kraft pulps. The molecular structures were characterized with ESI and MALDI MS. Analysis of the fine sequences was achieved by MS and MS/MS of the water-soluble oligosaccharides obtained by acid hydrolysis of the CNF gels. The analysis revealed the presence of two families: one corresponding to homoglucuronic acid sequences and the other composed by alternating glucose and glucuronic acid units. The CNF gels, alone or with the addition of the water-soluble oligosaccharides, were tested on Chili pepper (Capsicum annuum). Based on the characterization of the gene expression with Next Generation Sequencing (NGS) of the C. annuum's total messenger RNA, the differences in growth of the C. annuum seeds correlated well with the downregulation of the pathways regulating photosynthesis. A downregulation of the response to abiotic factors was detected, suggesting that these gels would improve the resistance of the C. annuum plants to abiotic stress due to, e.g., water deprivation and cold temperatures.

Phenolic-rich extract from Bryophyllum pinnatum leaf cultivated under drought stress conditions modulates the antioxidant and anti-inflammatory response

Bryophyllum pinnatum (Lam) Pers (Crassulaceae) is used in traditional medicine to treat inflammatory diseases. There is preclinical and clinical evidence that proves its anti-inflammatory effect. This species is a good source of phenolic compounds such as flavonoids, being quercetin 3-O-L-arabinopyranosyl-(1→2)-O-L-rhamnopyranoside (Bp1), the main compound. However, to ensure the reproducibility of raw material as an active pharmaceutical ingredient, it is necessary to standardize the production chain from cultivation to the final product. The aim of this study was to understand whether water stress increases the phenolic content in B. pinnatum leaves and its effect on the modulation of anti-inflammatory and antioxidant responses. B. pinnatum was submitted to drought stress, with daily watering suspended for specified periods: 0, 5, 10, 20, and 30 days, along with a cyclic regimen involving 10 days of water deprivation followed by 10 days of regular watering for recovery (denoted as T0, T5t, T10t, T20t, T30t, and T10tcyc, respectively). For each water stress treatment (n = 10), there were control plants (n = 10) that received daily watering. After treatment, dry leaf extracts from each sample were prepared. Subsequently, the total flavonoids (TFC) and total phenolics (TPC) content were performed using spectrophotometric tests. Ultrafast liquid chromatography was used to quantify the main compound (Bp1) in the extracts. Extracts under different stress conditions showed no signs of cytotoxicity (RAW 264.7 cells) and were able to donate electrons in in vitro assays (CAT, reducing power, and DPPH). Extracts with high TPC (T20t and T30t) in the ear edema model induced by croton oil at a dose of 200 mg/kg orally showed an anti-inflammatory effect when compared to positive control, dexamethasone (1 mg/kg, orally). Regarding the Bp1 content, no major differences between the groups were observed. The results demonstrate that water stress is a promising and sustainable strategy for cultivating B. pinnatum to increase the phenolic content and positively modulate its pharmacological effects. Therefore, phenolic-rich extract of B. pinnatum can be obtained with low water resource consumption and it is a good source to use as an active ingredient in herbal medicines or supplements.

DNA methylation regulates the secondary metabolism of saponins to improve the adaptability of Eleutherococcus senticosus during drought stress

Plant growth and development can be significantly impacted by drought stress. Plants will adjust the synthesis and accumulation of secondary metabolites to improve survival in times of water constraint. Simultaneously, drought stress can lead to modifications in the DNA methylation status of plants, and these modifications can directly impact gene expression and product synthesis by changing the DNA methylation status of functional genes involved in secondary metabolite synthesis. However, further research is needed to fully understand the extent to which DNA methylation modifies the content of secondary metabolites to mediate plants’ responses to drought stress, as well as the underlying mechanisms involved. Our study found that in Eleutherococcus senticosus (E. senticosus), moderate water deprivation significantly decreased DNA methylation levels throughout the genome and at the promoters of EsFPS, EsSS, and EsSE. Transcription factors like EsMYB-r1, previously inhibited by DNA methylation, can re-bind to the EsFPS promotor region following DNA demethylation. This process promotes gene expression and, ultimately, saponin synthesis and accumulation. The increased saponin levels in E. senticosus acted as antioxidants, enhancing the plant’s adaptability to drought stress.

Unveiling key mechanisms: Transcriptomic meta-analysis of diverse nanomaterial applications addressing biotic and abiotic stresses in Arabidopsis Thaliana

The potential applications of nanomaterials in agriculture for alleviating diverse biotic and abiotic stresses have garnered significant attention. The reported mechanisms encompass promoting plant growth and development, alleviating oxidative stress, inducing defense responses, modulating plant-microbe interactions, and more. However, individual studies may not fully uncover the common pathways or distinguish the effects of different nanostructures. We examined Arabidopsis thaliana transcriptomes exposed to biotic, abiotic, and metal or carbon-based nanomaterials, utilizing 24 microarray chipsets and 17 RNA-seq sets. The results showed that: 1) from the perspective of different nanostructures, all metal nanomaterials relieved biotic/abiotic stresses via boosting metal homeostasis, particularly zinc and iron. Carbon nanomaterials induce hormone-related immune responses in the presence of both biotic and abiotic stressors. 2) Considering the distinct features of various nanostructures, metal nanomaterials displayed unique characteristics in seed priming for combating abiotic stresses. In contrast, carbon nanomaterials exhibited attractive features in alleviating water deprivation and acting as signaling amplifiers during biotic stress. 3) For shared pathway analysis, response to hypoxia emerges as the predominant and widely shared regulatory mechanism governing diverse stress responses, including those induced by nanomaterials. By deciphering shared and specific pathways and responses, this research opens new avenues for precision nano-agriculture, offering innovative strategies to optimize plant resilience, improve stress management, and advance sustainable crop production practices.

Harsh environmental conditions promote cooperative behavior in an epiphytic fern

ABSTRACT Harsh, unpredictable environments are known to favor cooperative groups in animals. Whether plants exhibit similar relationships is unknown. Staghorn ferns (Platycerium bifurcatum, Polypodiaceae) are epiphytes that form cooperative groups which build communal water and nutrient ‘nests’ at the tops of trees, a habitat characterized by water and nutrient stress. We conducted field observations to test whether staghorn ferns continue to live in large, reproductively active groups after they become dislodged from the canopy and fall to the forest floor, where they are less limited by water and nutrient deprivation. To rule out the potentially confounding effects of light limitation on the forest floor, we also conducted a multi-year glasshouse experiment where we transplanted individual plants into soil and onto vertically oriented boards under standardized light conditions. Results from field observations showed that dislodged colonies formed smaller groups that reproduced less than epiphytic colonies. Results from the glasshouse experiment showed that even when growing in full sun, terrestrial individuals tended to remain solitary, while epiphytic individuals tended to recruit new individuals into colonies. Results also showed that plants growing in potting soil and exposed to full sunlight sporulated more heavily than plants growing epiphytically. However, localities that are characterized by both elevated soil and light resources are generally not available to staghorn ferns in the wild, perhaps with the exception of large, epiphytic colonies with well-developed nests at the top of tree canopies. Overall results indicate that the harsh environmental conditions at the tops of trees trigger the formation of colonies in staghorn ferns, similarly to group living animals.

Environmental impact assessment of direct lithium extraction from brine resources: Global warming potential, land use, water consumption, and charting sustainable scenarios

Direct Lithium Extraction (DLE) has emerged as an alternative that bypasses lengthy evaporation processes to produce lithium from brine sources. This study scrutinizes both direct and indirect environmental impacts of DLE, specifically focusing on global warming, land use, and water consumption in Clayton Valley, Nevada. It was compared to traditional brine and hard rock extraction methods. The DLE method is closely tied to energy usage, and this study has explored various scenarios for power sources. The TRACI, ReCiPe, and AWARE methods of life cycle assessment were employed to evaluate the environmental footprint, indirect land use, and water footprint of lithium production from various sources. According to the study, producing one ton of lithium carbonate using the DLE method showed distinct emissions profiles. Specifically, when electricity was sourced from a diesel generator, the Nevada grid, or solar panels, the emissions totaled approximately 22, 17.3, and 7.6 tons of CO2eq, respectively. Switching power sources goes beyond affecting greenhouse gas emissions; it also influences land use impacts and individual water consumption, as evaluated in this study. The direct land use for DLE is as follows: 16, 493, 182, and 659 m²/ton of Lithium Carbonate Equivalent (LCE) for processing plant, processing plant, well field, processing plant, solar panel area, and all regions required with solar panels, respectively. In assessing the water footprint, the study determined varying water deprivation potentials depending on the electricity source utilized: 3.7 m³eq/kg of LCE with a diesel generator, 9.5 m³eq/kg of LCE with the Nevada grid, and 4.2 m³eq/kg of LCE with solar panels.

The 3% hypertonic saline infusion test for the differential diagnosis of diabetes insipidus and primary polydipsia: assessment of diagnostic accuracy

AIM: assessment of the diagnostic accuracy of a 3% hypertonic saline infusion test in relation to a set of clinical and laboratory data (including a water deprivation test and MRI data) for differential diagnoses of diabetes insipidus (DI) and primary polydipsia (PP).METHODS: An interventional cross-sectional study was carried out at Endocrinology Research Centre From September 2021 to September 2023 ninety patients with polyuria-polydipsia syndrome were included. In order to assess the diagnostic characteristics, all the subjects underwent two tests with osmotic stimulation: a 3% hypertonic saline infusion test and a water deprivation test. Adverse events were assessed.RESULTS: Based on the results of clinical, anamnestic, laboratory and instrumental data, and the results of a water deprivation test, a final diagnosis of DI was made in 48 (53%) patients and PP in 42 (47%) patients. The agreement between the two samples is significant — Kappa = 0.823, 95% CI (0.707, 0.939). The operational parameters of the 3% hypertonic saline infusion test are: sensitivity 98% (95% CI: 89%; 100%); specificity 98% (95% CI: 87%; 100%), positive and negative predictive values 98% (95% CI: 89%–100%) and 98% (95% CI: 87%–100%). Respectively. Chills occurred significantly more often (31% vs. 12%), and dizziness and headache were more pronounced during the 3% hypertonic saline infusion test. The median duration of the water deprivation test in patients was 11 hours, and median duration of 3% hypertonic saline infusion test was 1.5 hour (P<0.001).CONCLUSION: The 3% hypertonic saline infusion test has a high overall diagnostic accuracy 98%; 95% CI 92% to 100%)) in relation to the classical set of clinical, laboratory and instrumental data of patients (including a water deprivation test), However, it is important the advantage of the latter is its short duration and, as a consequence, better tolerability and probably better compliance, while no significant differences in adverse events frequencies during the tests were identified.

Restraint stress induces blood-brain barrier injury in rat amygdala by activating the Rho/ROCK signaling pathway

To investigate the role of Rho/ROCK signaling pathway in mediating restraint stress-induced blood-brain barrier (BBB) injury in the amygdala of rats. Sixty male SD rats were randomized equally into control group (with food and water deprivation for 6 h per day), restraint stress group (with restraint for 6 h per day), stress + fasudil treatment (administered by intraperitoneal injection at 1 mg/100 g 30 min before the 6-h restraint) group, and fasudil treatment alone group. The elevated plus-maze test was used to detect behavioral changes of the rats, serum corticosterone and S100B levels were determined with ELISA, and Evans Blue leakage in the brain tissue was examined to evaluate the changes in BBB permeability. The changes in expression levels of tight junction proteins in the amygdala were detected using immunofluorescence assay and Western blotting, and Rho/ROCK pathway activation was detected by Pull-down test and Western blotting. Ultrastructural changes of the cerebral microvascular endothelial cells were observed using transmission electron microscopy. Compared with those in the control group, the rats in restrain stress group and stress+fasudil group showed obvious anxiety-like behavior with significantly increased serum corticosterone level (P<0.001). Compared with those in the control group and stress+fasudil group, the rat models of restrain stress showed more obvious Evans Blue leakage and higher S100B expression (P<0.01) but lower expressions of tight junction proteins in the amygdala. Pull-down test and Western blotting confirmed that the expression levels of RhoA-GTP, ROCK2 and P-MLC 2 were significantly higher in stress group than in the control group and stress + fasudil group (P<0.05). Transmission electron microscopy revealed obvious ultrastructural changes in the cerebral microvascular endothelial cells in the rat models of restrain stress. Restraint stress induces BBB injury in the amygdala of rats by activating the Rho/ROCK signaling pathway.

Genomic responses to climate: Understanding local adaptation in the Andean tree species Nothofagus pumilio and implications for a changing world

Societal Impact StatementForest trees tend to be strongly genetically adapted to their local environments, but climate change will probably subject trees to novel combinations of precipitation, temperature, and photoperiod. Local adaptation was investigated in the ecologically and economically important Patagonian tree species Nothofagus pumilio by characterizing its genetic diversity in relation to the varied environmental conditions across its range. These insights are useful for conservation and management decisions, for example by identifying suitable populations to establish seed source plantations for restoration and characterizing relationships with environmental drivers of selection to better understand how this species will respond to climate change.SummaryNothofagus pumilio is a foundation tree species that inhabits a 2000‐km‐long range in the southern Andes, a region with two perpendicular environmental gradients: temperature and photoperiod (North–South), and precipitation (West–East). We investigated local adaptation patterns by searching for relationships between environmental clines and signatures of adaptation in candidate genes related to stress response, growth, and phenology. Using a paired site sampling design within a landscape genome analysis, we analyzed 493 adult N. pumilio trees in 20 sampling sites across the species' latitudinal range. We screened 47,336 single nucleotide polymorphism (SNP) loci in 1632 contigs (i.e., coding regions along the genome). Population structure and genetic diversity analyses preceded four genome scan analyses using genetic and environmental data. Population structure and genetic diversity are mainly oriented along the latitude axis. Genome scans identified 445 outlier SNPs, which are loci showing signatures of selection. Temperature and photoperiod variables were associated with notably more outliers than precipitation. However, the most frequent biological functions among genes were water deprivation response and cold response, suggesting that stress response is comprised of complex and polygenic traits that are affected by many environmental variables. Our findings suggest that N. pumilio shows signatures of local adaptation to extant climate conditions, including temperature, photoperiod, and precipitation. However, climate change is likely to alter existing relationships among environmental conditions to which this species is currently adapted. These changes may have unpredictable consequences for the species' future survival, adaptation potential, and the people who depend upon these forests.

Towards phenotyping adaptive traits in camels: A study of the influence of hypotonic saline solutions on blood cell area.

Single-humped camels are livestock of physical, physiological, and biochemical adaptations to hot desert environments and to water scarcity. The tolerance of camels to water deprivation and their exceptional capacity for rapid rehydration requires blood cells with membranes of specialized organization and chemical composition. The objectives of this study are to examine the changes in the area (a proxy for volume) of camel blood cells in solutions with decreasing concentrations of NaCl and consequently identify the conditions under which blood cells can be phenotyped in a large population. Whole-blood samples from three healthy adult female camels were treated with four different concentrations of NaCl and examined at six incubation-periods. Observationally, red blood cells in all treatments remained intact and maintained their elliptical shape while white blood cells experienced some damage, lysing at concentrations below 0.90%. Average basal (in 0.90% NaCl) RBC area was ~15 μm² and swelled in the various treatments, in some cases reaching twice its original size. Excluding the damaged cells, the average area of combined WBCs, ~32.7 μm², expanded approximately three times its original size. We find that camel WBCs, like their RBCs, are adapted to hypotonic environments, and are capable of expanding while maintaining their structural integrity.

Hydration state does not affect selected body temperature during gravidity or gravidity duration in pythons (Antaresia childreni)

The embryonic development of many ectothermic species are highly sensitive to temperature and typically have a higher thermal optima than do most other physiological processes. Thus, female ectotherms often maintain a higher and more carefully controlled body temperature when she is supporting developing embryos (early development in oviparous species, throughout development in viviparous species). Considering the positive correlation between body temperature and evaporative water loss, this response could potentially exacerbate female water imbalance in water-limited environments, suggesting that female water balance and egg development may be in conflict. Using Children's pythons (Antaresia childreni), we hypothesized that water deprivation reduces thermophily during gravidity. We split reproductive females into two thermal treatments: those provided with a continuously available thermal gradient of 25–45 °C and those kept at a constant 31 °C. We also had seven non-reproductive females that were provided a thermal gradient. Within each thermal treatment group, we alternatingly assigned females to either have or not have water throughout gravidity. We found that reproduction increased female body temperature, but this increase was not affected by water regime. Reproduction also increased plasma osmolality, and lack of water during gravidity exacerbated this effect. We also found that thermal treatment, but not water regime, significantly influenced gravidity duration, with females given a thermogradient having a shorter gravidity duration, likely as a result of having a higher average body temperature than did the females provided constant heat. Finally, we found that females provided water throughout gravidity had greater clutch masses than did females without water. Further research is needed to improve scientific understanding of the interactions among water balance, body temperature, and various physiological performances.

Modulation of early gene expression responses to water deprivation stress by the E3 ubiquitin ligase ATL80: implications for retrograde signaling interplay

BackgroundPrimary response genes play a pivotal role in translating short-lived stress signals into sustained adaptive responses. In this study, we investigated the involvement of ATL80, an E3 ubiquitin ligase, in the dynamics of gene expression following water deprivation stress. We observed that ATL80 is rapidly activated within minutes of water deprivation stress perception, reaching peak expression around 60 min before gradually declining. ATL80, despite its post-translational regulation role, emerged as a key player in modulating early gene expression responses to water deprivation stress.ResultsThe impact of ATL80 on gene expression was assessed using a time-course microarray analysis (0, 15, 30, 60, and 120 min), revealing a burst of differentially expressed genes, many of which were associated with various stress responses. In addition, the diversity of early modulation of gene expression in response to water deprivation stress was significantly abolished in the atl80 mutant compared to wild-type plants. A subset of 73 genes that exhibited a similar expression pattern to ATL80 was identified. Among them, several are linked to stress responses, including ERF/AP2 and WRKY transcription factors, calcium signaling genes, MAP kinases, and signaling peptides. Promoter analysis predicts enrichment of binding sites for CAMTA1 and CAMTA5, which are known regulators of rapid stress responses. Furthermore, we have identified a group of differentially expressed ERF/AP2 transcription factors, proteins associated with folding and refolding, as well as pinpointed core module genes which are known to play roles in retrograde signaling pathways that cross-referenced with the early ATL80 transcriptome.ConclusionsBased on these findings, we propose that ATL80 may target one or more components within the retrograde signaling pathways for degradation. In essence, ATL80 serves as a bridge connecting these signaling pathways and effectively functions as an alarm signal.

Oesophageal obstruction by trichobezoars in rescued jungle cat (Felis chaus)

AbstractOesophageal obstruction due to hairballs in cats is very rare. Excessive grooming behaviour in cats due to skin infection can lead to impaction in the digestive tract, resulting in deprivation of food and water and ultimately death. This report described a case of a rescued jungle cat showing signs of marked dehydration after death. On postmortem examination, a blockade of hairballs was observed in the oesophagus. Further examination of hair revealed that the hair was from the same species, not the prey species. This suggests that the over‐grooming behaviour of cats can lead to the over‐ingestion of hair, which might cause a blockage in the digestive tract, leading to death. The rescue centres should be well aware and prepared to diagnose such problems and manage the case accordingly for effective treatment of rescued animals.

Mutation in Arabidopsis mitochondrial Pentatricopeptide repeat 40 gene affects tolerance to water deficit

Main ConclusionThe Arabidopsis Pentatricopeptide repeat 40 (PPR40) insertion mutants have increased tolerance to water deficit compared to wild-type plants. Tolerance is likely the consequence of ABA hypersensitivity of the mutants.Plant growth and development depend on multiple environmental factors whose alterations can disrupt plant homeostasis and trigger complex molecular and physiological responses. Water deficit is one of the factors which can seriously restrict plant growth and viability. Mitochondria play an important role in cellular metabolism, energy production, and redox homeostasis. During drought and salinity stress, mitochondrial dysfunction can lead to ROS overproduction and oxidative stress, affecting plant growth and survival. Alternative oxidases (AOXs) and stabilization of mitochondrial electron transport chain help mitigate ROS damage. The mitochondrial Pentatricopeptide repeat 40 (PPR40) protein was implicated in stress regulation as ppr40 mutants were found to be hypersensitive to ABA and high salinity during germination. This study investigated the tolerance of the knockout ppr40-1 and knockdown ppr40-2 mutants to water deprivation. Our results show that these mutants display an enhanced tolerance to water deficit. The mutants had higher relative water content, reduced level of oxidative damage, and better photosynthetic parameters in water-limited conditions compared to wild-type plants. ppr40 mutants had considerable differences in metabolic profiles and expression of a number of stress-related genes, suggesting important metabolic reprogramming. Tolerance to water deficit was also manifested in higher survival rates and alleviated growth reduction when watering was suspended. Enhanced sensitivity to ABA and fast stomata closure was suggested to lead to improved capacity for water conservation in such environment. Overall, this study highlights the importance of mitochondrial functions and in particular PPR40 in plant responses to abiotic stress, particularly drought.

Hypokalemia Induced Partial Nephrogenic Diabetes Insipidus: A Case Report

Diabetes insipidus is a condition characterised by a large volume of diluted urine production andincreased thirst. In this case report, a 49-year-old gentleman presented with 3 months of polyuria andpolydipsia. He had a repeated history of hypokalemia. On the evaluation of polyuria and polydipsia,he was diagnosed with partial nephrogenic diabetes insipidus based on his inability to concentrateurine after a water deprivation test and his less than 50% response to exogenous desmopressin.On the evaluation of recurrent hypokalemia, the investigation reports met biochemical criteria forthe diagnosis of Gitelman syndrome. He was encouraged to increase his fluid intake as required,and potassium chloride supplementation relieved his symptoms. This case report demonstrates thereversibility of nephrogenic diabetes insipidus with a correction of hyperkalemia.

Appetitively motivated tasks in the IntelliCage reveal a higher motivational cost of spatial learning in male than female mice.

The IntelliCage (IC) permits the assessment of the behavior and learning abilities of mice in a social home cage context. To overcome water deprivation as an aversive driver of learning, we developed protocols in which spatial learning is motivated appetitively by the preference of mice for sweetened over plain water. While plain water is available at all times, only correct task responses give access to sweetened water rewards. Under these conditions, C57BL/6J mice successfully mastered a corner preference task with the reversal and also learned a more difficult time-place task with reversal. However, the rate of responding to sweetened water decreased strongly with increasing task difficulty, indicating that learning challenges and reduced success in obtaining rewards decreased the motivation of the animals to seek sweetened water. While C57BL/6J mice of both sexes showed similar initial taste preferences and learned similarly well in simple learning tasks, the rate of responding to sweetened water and performance dropped more rapidly in male than in female mice in response to increasing learning challenges. Taken together, our data indicate that male mice can have a disadvantage relative to females in mastering difficult, appetitively motivated learning tasks, likely due to sex differences in value-based decision-making.

Syntrichia ruralis: emerging model moss genome reveals a conserved and previously unknown regulator of desiccation in flowering plants.

Water scarcity, resulting from climate change, poses a significant threat to ecosystems. Syntrichia ruralis, a dryland desiccation-tolerant moss, provides valuable insights into survival of water-limited conditions. We sequenced the genome of S. ruralis, conducted transcriptomic analyses, and performed comparative genomic and transcriptomic analyses with existing genomes and transcriptomes, including with the close relative S. caninervis. We took a genetic approach to characterize the role of an S. ruralis transcription factor, identified in transcriptomic analyses, in Arabidopsis thaliana. The genome was assembled into 12 chromosomes encompassing 21 169 protein-coding genes. Comparative analysis revealed copy number and transcript abundance differences in known desiccation-associated gene families, and highlighted genome-level variation among species that may reflect adaptation to different habitats. A significant number of abscisic acid (ABA)-responsive genes were found to be negatively regulated by a MYB transcription factor (MYB55) that was upstream of the S. ruralis ortholog of ABA-insensitive 3 (ABI3). We determined that this conserved MYB transcription factor, uncharacterized in Arabidopsis, acts as a negative regulator of an ABA-dependent stress response in Arabidopsis. The new genomic resources from this emerging model moss offer novel insights into how plants regulate their responses to water deprivation.

Acoustic detection of the effects of prolonged fasting on newly hatched broiler chickens

Water and food deprivation during the first few hours of life can act as a significant stressor for birds, as it can negatively affect their physical and immunological development. By providing essential nutrients, new enriched hydrated gels help alleviate the potential risks associated with prolonged fasting periods. Broiler chickens vocalisations are considered reliable indicators of changes in stress, anxiety and well-being. In this study, the results of recorded broiler vocalisations are presented together with a statistical analysis of the acoustic parameterisation. We focused on the hours preceding the transport of chicks from the hatchery to the breeding farm, dividing the animals into a control group that replicated real conditions, and a treatment group with the administration of a hydrated gel. The objectives of this study were to validate the effectiveness of continuous audio recording in monitoring stress level in food-deprived chicks, and to identify the most significant acoustic parameters. The selection of the acoustic parameters was based on a previous study conducted on broiler farms, which showed a strong linear relationship between the number of vocalisations, spectral centroid, and the bandwidth. Significant differences were observed between the first and last three hours. Furthermore, 8 h after gel ingestion, vocalisations indicated reduced stress levels.