Physiological Changes Research Articles

Intermittent Fasting During Ramadan Increases the Absolute Number of Circulating Progenitor Stem Cells in Healthy Subjects.

Fasting regimens have shown profound impact on pro-longevity and tissue regeneration in diverse species. Physiological events can induce a regenerative response in adult stem cells. However, little is known about signaling and activation of adult stem cells which are modulated by fasting. This study analyzed the presence of hematopoietic stem/progenitor cells (HSPCs) and their circulation in the peripheral blood (PB) of healthy male adults practicing Ramadan fasting. Ten healthy male volunteers were enrolled in this prospective observational study. PB samples were collected twice daily on days 0, 10, 20, and 30 of Ramadan fasting (RF). Populations of stem cells and serum soluble factors were analyzed by flow cytometry. As a response to RF, we report an increase in the average absolute count of circulating of HSPCs, defined as LIN-CD45- and LIN-CD45+ cell subsets expressing the stem markers, CD34 and CD133. Changes in the number of HSPCs subsets reflected changes in the peripheral concentration of chemoattractant soluble factors during fasting. A chemotaxis assay showed a migratory property of HSPCs towards plasma, collected at D30 of fasting that contained a higher concentration of SCF and G-CSF. The relationship between RF and an increase in the number of circulating HSPCs in part, describes a regenerative response to the physiological changes during fasting and may open opportunities to define the role of dietary intervention in the stem cell therapy.

Non-Invasive Photoacoustic Cerebrovascular Monitoring of Early-Stage Ischemic Strokes In Vivo.

Early-stage stroke monitoring enables timely intervention that is crucial to minimizing neuronal damage and increasing the extent of recovery. By monitoring collateral circulation and neovascularization after ischemic stroke, the natural recovery process can be better understood, optimize further treatment strategies, and improve the prognosis. Photoacoustic computed tomography (PACT), a non-invasive imaging modality that captures multiparametric high-resolution images of vessel structures, is well suited for evaluating cerebrovascular structures and their function. Here 3D multiparametric transcranial PACT is implemented to monitor the early stage of a photothrombotic (PT)-stroke model in living rats. New vessels in the PT-induced region are successfully observed using PACT, and these observations are confirmed by histology. Then, using multiparametric PACT, it is found that the SO2 in the ischemic area decreases while the SO2 in newly formed vessels increases, and the SO2 in the PT region also recovers. These findings demonstrate PACT's remarkable ability to image and monitor cerebrovascular morphologic and physiological changes. They highlight the usefulness of whole-brain PACT as a potentially powerful tool for early diagnosis and therapeutic decision-making in treating ischemic stroke.

Recording the peculiarities of life activities fixed on the surface of the incisors of the spotted ground squirrel (Spermophilus suslicus, Rodentia, Sciuridae)

The increments on the surface of the incisors of young spotted ground squirrels are wide, of medium definition. They probably reflect intensive nutrition and growth of the body. Starting with the third month of life, growth slows down, the width of the growths is decreased, and they become narrower and more distinct. Deformations appear in the form of swellings of the incisor wall. The frequency of occurrence of the deformations in underyearlings reaches a peak in the second half of July. The same pattern is observed in adult ground squirrels. By this time, gophers reach their maximum body weight. The majority of adult ground squirrels kept in captivity also reach the maximum body weight in the first half of July, this indirectly indicating the relationship between the appearance of deformations and the achievement of maximum fatness. Under laboratory conditions, at a temperature not exceeding 22°C, overwintered males and dry females after reaching their maximum body weight, even in the presence of food, fall into a stupor resembling a state of hibernation. Their body temperature is only 1–1.5°C higher than the room temperature, the animals are lethargic, they do not open their eyes during manipulations, and the frequency of breaths is 4–6 per minute. These observations suggest that ground squirrels living in natural conditions also fall into a similar hibernation, since the proportion of overwintered males and females among the individuals caught in the middle of summer is decreased. The appearance of deformations at this time seems to be associated with a violation of the normal growth of the incisors during physiological changes in the body, these being caused by the onset of a transition from the active nutrition of plant food to endogenous consumption of fat reserves characteristic of the state of hibernation. The record of autumn-winter hibernation is characterized by very narrow increments or deformations, a change in the enamel boundary, as well as a change in the contour of the incisor surface. After spring awakening, growths are at first narrow and distinct, 150–160 µm each, subsequently increasing in width, which is probably due to a gradual transition from endogenous nutrition of the body with fat deposits during hibernation to intensive nutrition of green vegetation. Lactation of females usually does not affect daily gains.

Analysing physiological urinary hormonal changes in female red pandas during the breeding season.

This study aimed to contribute to the conservation of red pandas by improving the understanding of their oestrus cycle through examining urinary hormone changes during their breeding season. To minimize stress associated with blood sample collection, we used urine samples Sex hormone levels were measured over six months in pregnant and nonpregnant red pandas, to help understand changes in oestrogen concentrations during oestrus, post-mating progesterone concentrations and differences in ceruloplasmin concentrations. The results of the study revealed that female red pandas are polyoestrous, with a second oestrogen peak after mating. Progesterone changed in a cascading fashion, peaking and then gradually declining. Successfully mated females showed higher levels of progesterone than unsuccessfully mated females, which had no peak in progesterone after mating. Ceruloplasmin was measured to confirm pregnancy, but its value as a pregnancy diagnostic factor was not confirmed. These results provide significant insights into the reproductive physiology of red pandas and lay the foundation for additional research towards improving the management and breeding strategies for this threatened species.

Sexuality and pregnancy: Beliefs and dysfunctions in pregnant women.

Pregnancy brings out significant physiological, psychological, and sexual changes that may lead to sexual dysfunction. Our study aimed to explore common beliefs about sexuality during pregnancy among pregnant women and to assess sexual dysfunction in this population. We conducted a cross-sectional study between March and August 2022, involving pregnant women regardless of their pregnancy term. A self-administered questionnaire was digitized using Google Forms®, and the Female Sexual Function Index was used to identify the presence of sexual dysfunction. A total of 34 women with a mean age of 31.56 ± 3.25 years participated in our study. Among the participating women, 29.5% had questions about sexuality during pregnancy, 26.5% sought information from caregivers, and 41.2% received spontaneous information from their doctors. Regarding common beliefs, some pregnant women thought that sexual intercourse could harm the fetus (20.6%) or their own health (17.6%). Sexual dysfunction was found in 70.6%, and no significant associations were found between the presence of sexual dysfunction and the sociodemographic or clinical data related to ongoing pregnancy. The prevalence of female sexual dysfunction during pregnancy is quite high. Providing accurate information and advice from trained professionals can dispel misconceptions, demystify beliefs about sexuality, and improve the sexual performance of couples during pregnancy.

Impact of extended lairage periods on physio-metabolic status and meat quality in commercial broilers

ABSTRACT 1. This study investigated the impact of different lairage duration on physiology, metabolism and meat quality in commercial broilers. 2. A total of sixty, one-d-old Vencobb broilers were reared until 42 d of age and subjected to five lairage treatments (T0-T5), with the control with no lairage and then each timepoint increasing by 2 h. 3. Head, eye and feet temperature increased progressively (P˂0.05), from 21 to 42 d. During lairage, temperature for the head, eye and feet were significantly higher in birds held until T3-T4 (P˂0.05), than at T0-T2 and T5 treatments. 4. Serum total protein, creatinine, lipase and TBARS showed no variation due to lairage (p > 0.05). Glucose levels were highest at T4 (p < 0.05) than at T1-T3 or T5 and serum albumin increased only at T4 as compared to T5 (p < 0.05). Higher levels for blood triglycerides were recorded for T0, T1 and T5 (p < 0.05), than at T2-T4 and total blood antioxidants were significantly higher at T1 (p < 0.05), than at T0 and T2-T5 treatments, respectively. 5. There was no significant difference for meat pH, ERV and WHC (p > 0.05), while, higher tyrosine levels (p < 0.05) were noted for birds in T5 than for the rest of the lairage treatments (T0-T4). On the same trend, TBA concentration was highest for birds in T5, as compared to T4 (p < 0.05). 6. In conclusion, lairage over eight hours for commercial broilers is not recommended, as there are drastic changes in physiology, metabolism and deterioration of meat, reducing meat quality.

5-Aminolevulinic Acid (5-ALA)-Induced Drought Resistance in Maize Seedling Root at Physiological and Transcriptomic Levels

Drought stress seriously affects the growth, development, yield, and quality of maize. This study aimed to investigate the effects of exogenous 5-ALA on root morphology and physiological changes in maize seedlings and to detect its regulatory network. The results showed that adding 25 mg/L 5-ALA accelerated root morphogenesis (root average diameter, main root length, total root length, and root surface area) and promoted dry matter accumulation and free radical removal. Transcriptome analysis showed that after applying exogenous 5-ALA, differently expressed genes (DEGs) were mainly involved in histidine metabolism, amino acid biosynthesis, plasma membrane components, secondary active sulfate transmembrane transporter activity, and anion reverse transporter activity. Two inbred lines specifically responded to organelle and structural molecular activity, and 5-ALA may regulate maize roots to achieve drought tolerance through these two pathways. In addition, candidate genes that may regulate maize root growth were screened by weighted gene co-expression network analysis (WGCNA). These genes may play important roles in alleviating drought stress through lignin synthesis, heat shock proteins, iron storage and transport, calcium binding proteins, and plasma membrane regulation of exogenous regulator 5-ALA. Our results may provide a theoretical basis for clarifying the response of maize seedling roots to drought and the mechanism of exogenous hormones in alleviating drought.

Neurochemical dynamics during two hypnotic states evidenced by magnetic resonance spectroscopy

This study explores neurochemical changes in the brain during hypnosis, targeting the parieto-occipital (PO) and posterior superior temporal gyrus (pSTG) regions using proton magnetic resonance spectroscopy (MRS). We examined 52 healthy, hypnosis experienced participants to investigate how two different hypnotic states of varying depth impacted brain neurochemistry in comparison to each other and to their respective non-hypnagogic control conditions. Alongside neurochemical assessments, we recorded respiration and heart rate variability (HRV) to further explore possible associations between physiological correlates of hypnotic depth. Significant changes in myo-Inositol concentration relative to total creatine were observed in the PO region during the deeper hypnosis state, possibly indicating reduced neuronal activity. No significant neurochemical shifts were detected in the pSTG region. Additionally, our findings revealed notable physiological changes during hypnosis. Respiratory rates were significantly slowed in both hypnotic states compared to the respective controls, with more pronounced slowing in the deeper hypnotic state. This study contributes a first-time insight into neurochemical responses during hypnotic states. We hope offering a foundation for further research in understanding the neurobiological correlates of hypnosis in both, basic science and—down the line—clinical applications.

Taste triggers a homeostatic temperature control in hungry flies.

Hungry animals consistently show a desire to obtain food. Even a brief sensory detection of food can trigger bursts of physiological and behavioral changes. However, the underlying mechanisms by which the sensation of food triggers the acute behavioral response remain elusive. We have previously shown in Drosophila that hunger drives a preference for low temperature. Because Drosophila is a small ectotherm, a preference for low temperature implies a low body temperature and a low metabolic rate. Here, we show that taste-sensing triggers a switch from a low to a high temperature preference in hungry flies. We show that taste stimulation by artificial sweeteners or optogenetics triggers an acute warm preference, but is not sufficient to reach the fed state. Instead, nutrient intake is required to reach the fed state. The data suggest that starvation recovery is controlled by two components: taste-evoked and nutrient-induced warm preferences, and that taste and nutrient quality play distinct roles in starvation recovery. Animals are motivated to eat based on time of day or hunger. We found that clock genes and hunger signals profoundly control the taste-evoked warm preferences. Thus, our data suggest that the taste-evoked response is one of the critical layers of regulatory mechanisms representing internal energy homeostasis and metabolism.

Taste triggers a homeostatic temperature control in hungry flies

Hungry animals consistently show a desire to obtain food. Even a brief sensory detection of food can trigger bursts of physiological and behavioral changes. However, the underlying mechanisms by which the sensation of food triggers the acute behavioral response remain elusive. We have previously shown in Drosophila that hunger drives a preference for low temperature. Because Drosophila is a small ectotherm, a preference for low temperature implies a low body temperature and a low metabolic rate. Here, we show that taste-sensing triggers a switch from a low to a high temperature preference in hungry flies. We show that taste stimulation by artificial sweeteners or optogenetics triggers an acute warm preference, but is not sufficient to reach the fed state. Instead, nutrient intake is required to reach the fed state. The data suggest that starvation recovery is controlled by two components: taste-evoked and nutrient-induced warm preferences, and that taste and nutrient quality play distinct roles in starvation recovery. Animals are motivated to eat based on time of day or hunger. We found that clock genes and hunger signals profoundly control the taste-evoked warm preferences. Thus, our data suggest that the taste-evoked response is one of the critical layers of regulatory mechanisms representing internal energy homeostasis and metabolism.

Biogenic volatile organic compounds (BVOCs) emissions and physiological changes in Pinus densiflora and Quercus acutissima seedlings under elevated particulate matter (PM)

Urban trees effectively reduce air pollution, including particulate matter (PM), which is a major concern in East Asia. While acting as biofilters, urban trees can be affected by PM exposure, which hinders their growth and physiological functions, thereby reducing their pollution mitigation ability. Trees absorb pollutants but also emit biogenic volatile organic compounds (BVOCs), which can act as precursors to other forms of air pollution. To better understand the effects of PM on urban trees, this study examined how two tree species, Pinus densiflora and Quercus acutissima, respond to elevated PM levels under controlled conditions at a concentration of 300 μg m−3. The aim was to investigate how increased PM levels affect BVOCs emissions and physiological responses in seedlings, and how these physiological changes influence BVOCs emission pattern. The results revealed species-specific responses in BVOCs emissions under PM stress with being especially oxygenated monoterpenes more than non‑oxygenated monoterpenes. Increased PM adsorption was found to reduce photosynthetic abilities, including photosynthesis (Anet), carboxylation capacity (Vcmax), and electron transport rate (J). This reduction in photosynthetic efficiency was further evidenced by decreased chlorophyll content and light absorption, which were assessed through chlorophyll fluorescence measurements. Additionally, the study evaluated oxidative stress indicators, such as lipid peroxidation and the accumulation of reactive oxygen species (ROS), to provide a comprehensive understanding of the species' responses to elevated PM conditions. The study found that elevated PM conditions were closely linked to an increase in oxygenated monoterpenes, which was associated with both oxidative stress and impaired physiological function. These observations emphasize the need for strategic urban tree selection to enhance air quality and suggest that understanding species-specific BVOCs emissions in response to PM is crucial for optimizing urban green spaces for health and environmental benefits.

Oxidative and endoplasmic reticulum stress in diabetes-related hearing loss: Protective effects of thioredoxin

Diabetes mellitus (DM) induces complex physiological changes in the inner ear environment. This study investigates the roles of oxidative stress (OS) and endoplasmic reticulum stress (ERS) in diabetic hearing loss and explores the potential of thioredoxin (Trx) in regulating OS, ERS, and apoptosis-related factors to mitigate the progression of hearing impairment. We conducted auditory and serological assessments in 63 patients with type 2 diabetes and 30 healthy controls. Type 2 diabetes models were induced in wild-type and Trx transgenic (Tg) mice, with auditory brainstem response (ABR) used to evaluate hearing changes. Cochlear tissues were isolated to analyse markers of apoptosis, OS, and ERS. Both patients with diabetes and mouse models exhibited hearing loss, alongside increased serum levels of Trx1, TXNIP, and AOPP, indicating oxidative damage. H&E and succinate dehydrogenase (SDH) staining revealed varying degrees of hair cell loss from the base to the apex of the cochlea in diabetic mice, with decreased expression of the hair cell protein prestin gene. Notably, Tg mice showed significant delay in hearing loss progression. In vitro, advanced glycation end-products (AGEs) induced OS and ERS in cochlear-like HEI-OC1 cells, while Trx overexpression enhanced Nrf2 activity, alleviating AGE-induced cellular stress. In conclusion, Trx exhibits protective effects against diabetes-related hearing loss, potentially by enhancing Nrf2/HO-1/SOD2 function to reduce OS and ERS.

Deep learning model for detection acute cardiogenic pulmonary edema in cases of preeclampsia

&lt;span lang="EN-US"&gt;The physiological changes during the pregnancy period increase the risk of developing pulmonary edema and acute respiratory failure. This condition falls under critical medical emergencies associated with maternal mortality. This study utilized a convolutional neural networks (CNN) architectural model employing chest Xray dataset images. CNN utilizes the convolution process by moving a convolutional kernel of a certain size across an image, allowing the computer to derive new representative information from the multiplication of portions of the image with the utilized filter.&lt;/span&gt;&lt;span lang="EN-US"&gt;To simplify, the vanishing gradient issue occurs when information dissipates before reaching its destination due to the lengthy path between input and output layers. This study was developed model for detection acute cardiogenic pulmonary Edema in pre-eclampsia cases using chest Xray images, implemented using PyTorch, Keras, and MxNet. The validated model achieved its optimum with accuracy 90.65% and binary cross-entropy loss (BCELoss) value of 0.4538. It exhibited an improved sensitivity value of 83.514% using a 5% dataset and a specificity value of 57.273%. This indicates an increase in sensitivity value by 83.514% using a 5% data set and a specificity value of 57.273%. The research results demonstrate an improvement in accuracy compared to several similar studies that also utilized CNN models.&lt;/span&gt;

Impact of homologous overexpression of PR10a gene on improving salt stress tolerance in transgenic Solanum tuberosum

Abiotic stresses severely affected crop productivity and considered to be a major yield limiting factor for crop plant. The tolerance to these stresses is a very complex phenomenon involving a wide array of molecular, biochemical and physiological changes in plant cells. Therefore, it is challenging to understand the molecular basis of abiotic stress tolerance to manipulate it for improving abiotic stress tolerance of major crops. Biotechnological approaches and genetic engineering including homologous gene overexpression can be implemented to understand gene functions under well-defined conditions. The Pathogenesis-related proteins (PR10) such as PR10a play multiple roles in biotic and abiotic stress tolerance and, hence, plant development. A PR10a gene from potato cv. Deseree was introduced into three cultivars of potato (Solanum tuberosum L.) by Agrobacterium tumefaciens-mediated genetic transformation. Transgenic plants were selected on a medium containing 1.0 mg/l phosphinothricin (PPT) and confirmed by polymerase chain reaction (PCR), herbicide (BASTA®) leaf paint assay, and Real-Time- quantitative PCR analyses (qPCR). All of the selected transformants showed completely tolerance to the application of PPT application. Experiments designed for testing salt tolerance revealed that there was enhanced salt tolerance of the transgenic lines in vitro in terms of morphological (plant FW, plant DW and plant height) and antioxidant activates as compared to the non-transgenic control plants. qRT-PCR showed that the expression of PR10a gene in the transgenic potato is higher than that in non-transgenic control under salt stress. The relative PR10a gene-expression patterns in the transgenic plants shed lights into the molecular response of homologues overexpressed PR10a potato to salt-stress conditions. The obtained results provide insights on the fact that PR10a plays a major role regarding salt stress tolerance in potato plants

Model-Based Dose Selection of a Sphingosine-1-Phosphate Modulator, Etrasimod, in Patients with Various Degrees of Hepatic Impairment

Background/Objectives: Etrasimod is a newly FDA-approved Sphingosine-1-Phosphate modulator indicated for moderate and severe ulcerative colitis. It is extensively metabolized in the liver via the cytochrome P450 system and may accumulate markedly in patients with hepatic dysfunction, exposing them to toxicity. The aim of the current study is to utilize a physiologically-based pharmacokinetic modeling approach to evaluate the impact of hepatic impairment on the pharmacokinetic behavior of etrasimod and to appropriately select dosage regimens for patients with chronic liver disease; Methods: PK-Sim was used to develop the etrasimod PBPK model, which was verified using clinical data from healthy subjects and subsequently adapted to reflect the physiological changes associated with varying degrees of hepatic dysfunction; Results: Simulations indicated that hepatic clearance of etrasimod is clearly reduced in patients with Child–Pugh B and C liver impairment. Based on these findings, dosing adjustments were proposed to achieve therapeutic exposures equivalent to those in individuals with normal liver function. In the Child–Pugh B and C population groups, 75% and 62.5%, respectively, of the standard dose were enough to have comparable exposure to the healthy population. These adjusted dosages aim to mitigate the risk of drug toxicity while maintaining efficacy; Conclusions: The PBPK model provides a robust framework for individualizing drug therapy in patients with hepatic impairment, ensuring safer and more effective treatment outcomes. Further clinical studies are warranted to verify these dosing recommendations and to refine the model for broader clinical applications.

Biodegradable microplastics induce profound changes in lettuce (Lactuca sativa) defense mechanisms and to some extent deteriorate growth traits

The development of agricultural technologies has intensified the use of plastic in this sector. Products of plastic degradation, such as microplastics (MPs), potentially threaten living organisms, biodiversity and agricultural ecosystem functioning. Thus, biodegradable plastic materials have been introduced to agriculture. However, the effects of biodegradable plastic substitutes on soil ecosystems are even less known than those of traditional ones. Here, we studied the effects of environmentally relevant concentrations of MPs prepared from a biodegradable plastic (a starch-polybutylene adipate terephthalate blend, PBAT-BD-MPs) on the growth and defense mechanisms of lettuce (Lactuca sativa) in CLIMECS system (CLImatic Manipulation of ECosystem Samples). PBAT-BD-MPs in the highest concentrations negatively affected some traits of growth, i.e., dry weight percentage, specific leaf area, and both C and N contents. We observed more profound changes in plant physiology and biochemistry, as PBAT-BD-MPs decreased chlorophyll content and triggered a concerted response of plant defense mechanisms against oxidative stress. In conclusion, exposure to PBAT-BD-MPs induced plant oxidative stress and activated plant defense mechanisms, leading to oxidative homeostasis that sustained plant growth and functioning. Our study highlights the need for in-depth understanding of the effect of bioplastics on plants.

Management of labor and delivery in space

In the zero-gravity environment of space, astronauts experience significant physiological and biochemical changes. Upon returning to Earth, they undergo another transformation and must participate in rehabilitation to readapt to Earth's gravity. Notably, female astronauts of the European Space Agency and NASA are currently prohibited from becoming pregnant during their missions. However, there is no such prohibition for pregnancy during commercial space missions. for a mother-astronaut, the physiological changes are multi-staged and complex. These changes encompass various phases: during pregnancy, throughout the active phase of labor, while being in space, and finally, upon returning to Earth. Comparing the physiological changes a woman undergoes during pregnancy with those experienced due to the absence of gravity provides valuable insights.

Deep phenotyping the right ventricle to establish translational MRI biomarkers for characterization of adaptive and maladaptive states in pulmonary hypertension

Deep phenotyping the right ventricle (RV) is essential for understanding the mechanisms of adaptive and maladaptive RV responses to pulmonary hypertension (PH). In this study, feature selection coupled with machine learning classification/ranking of specific cardiac magnetic resonance imaging (MRI) features from cine-MRI, flow-sensitized, and extracellular-volume techniques were used to assess RV remodelling in monocrotaline (MCT) and Sugen hypoxia (SuHx) PH rats. Early physiological changes associated with RV adaptation were detected along with prediction of RV maladaptive outcomes. Key adaptation features included haemodynamic alterations of pulmonary blood flow ejection and wave reflection, mild RV dilatation, progressive RV hypertrophy with subtle extracellular volume growth of RV wall. A dominant component of maladaptation was the extracellular matrix increase at RV insertion points and septum, observations compatible with histopathologic and RNA-sequencing results. The upregulation of mammalian target of rapamycin (mTOR) paralleled by AMP-activated protein kinase (AMPK) deactivation was seen at 4-week MCT and 8-week SuHx, along with reduced sarcoplasmic/endoplasmic reticulum Ca2+ATPase (SERCA2) expression, strongly associated with the RV systolic malfunction seen at this stage in vivo. The here established MRI features can serve as potential imaging biomarkers to evaluate PH treatment efficacy in preclinical studies and build up translational markers for the PH clinic.

Physiological parameters dictate bearing pattern in different mango cultivars: Study from Sub-tropical India

The bearing habit of mango has long been a subject of interest for pomologists. The difference in bearing pattern among various mango cultivars is attributed to complex physiological interaction. Despite multiple studies on mango bearing, detailed investigations in this area remain limited. This study aims to explore the interrelationship between the bearing patterns and the associated physiological changes in different mango cultivars. The physiological parameters were examined at various growth stages in Baramasi (a perennial bearer), Amrapali (a regular bearer) and Langra and Alphonso (irregular bearer) of mango (Mangifera indica L.). Significant variations were observed in chlorophyll content, internal carbon dioxide concentration, photosynthetic rate and flowering intensity. An increase in internal carbon dioxide concentration led to reduced carbon dioxide uptake, which impacted net photosynthesis production. A direct correlation between flowering intensity and photosynthetic rate was identified, while a nonlinear relationship between photosynthetic rate and total carbohydrate content was also noted. The study suggests that variations in the photosynthetic rate and the subsequent source-sink relationship may contribute to the differences in bearing patterns across mango cultivars. While further studies are needed for more conclusive results, this research can be valuable for pomologists, physiologists and breeders working with mango.

Juvenile hormone regulates reproductive diapause through both canonical and noncanonical pathways in the bean bug Riptortus pedestris

Diapause is an adaptive developmental arrest commonly utilized by animals to cope with seasonal changes. Central to this process are hormonal events that bridge photoperiodic cues and physiological changes. In insect reproductive diapause, the absence of juvenile hormone (JH) serves as the primary endocrine event that governs key diapause traits, including ovarian developmental arrest and lipid accumulation. Conventionally, it is believed that the effects of JH are conveyed through the receptor Methoprene-tolerant (Met) and its transcriptional factor Krüppel homolog 1 (Kr-h1). However, our study with the bean bug Riptortus pedestris reveals that JH independently regulates lipid accumulation, bypassing Met and Kr-h1 pathways. R. pedestris enters reproduction under long-day (LD) conditions, while diapause occurs under short-day (SD) conditions. Treatment of SD females with the JH mimic methoprene stimulated reproductive activities, enhancing ovary development and reducing lipid accumulation. In contrast, silencing genes essential for JH biosynthesis in LD females led to pronounced diapause characteristics, including ovarian developmental arrest and substantial lipid accumulation. Interestingly, disruptions in the JH action genes, either Met or Kr-h1, solely affected ovary development, leaving lipid accumulation unchanged, indicating an independent pathway for regulating JH in lipid accumulation. This was further confirmed by RNA interference experiments in SD females, where knockdown of Met or Kr-h1 did not alter the effects of methoprene on lipid reduction. Collectively, these results suggest that JH controls ovary development through the established Met-Kr-h1 pathway, while it modulates lipid accumulation through an alternative, yet to be identified noncanonical pathway during reproductive diapause in R. pedestris.