Later Stages Of Maturation Research Articles

Identification of the central tolerance checkpoint for autoreactive proteinase 3+ B cells in human bone marrow

Major target antigens of ANCA-associated vasculitis (AAV) are myeloperoxidase (MPO) and proteinase 3 (PR3). High-affinity MPO- and PR3-ANCA immunoglobulins are produced by antigen-experienced, class-switched autoreactive B cells. To prevent autoreactivity, B cells are subjected to several self-tolerance checkpoints, from the early immature stages in the bone marrow (BM), collectively called “central tolerance”, to late mature stages, collectively called “peripheral tolerance”; the latter was recently elucidated for autoreactive PR3+ B cells.Here we investigated central tolerance controlling immature PR3+B cells in the BM before their migration into the periphery as transitional B cells. We applied an established flow cytometry-based method using labeled recombinant PR3 (rPR3) to identify the PR3+B cells to compare the phenotype of PR3+B cells in paired samples of BM mononuclear cells (BMMC) and peripheral blood mononuclear cells (PBMC) of non-vasculitis controls (No-AAV), and PBMC of patients with PR3-ANCA-associated vasculitis (PR3-AAV).We observed that the proportion of PR3+B cells within BMMC was higher (median [IQR]; 1.98 % [1.77–2.75]) than within PBMC of No-AAV (0.9 % [0.63–1.44], p < 0.01 by paired comparison) and similar to their proportion within PBMC of patients with PR3-AAV (1.82 % [1.66–3.21]; p > 0.05). Within CD24++CD38++ B cells, the subset of B cell migrating from BM to the periphery, BMMC contained a greater proportion of PR3+B cells as compared to PBMC in No-AAV (3.35 % [1.99–4.92] versus 1.23 % [0.62–1.55], p < 0.01), showing different surface markers of maturation (i.e. higher proportion of CD27−CD10+ and lower expression of CD21, IgD, IgM). Importantly, we observed a significant decline of the PR3+ fraction from the immature subset (IgD−IgM+; 2.80 % [1.23–4.02]) to the early transitional subset (IgD+IgM+; 1.76 % [0.96–2.68], p < 0.01) in BMMC, while no significant reduction was observed between the early transitional of BMMC and the transitional compartment of PBMC in No-AAV (1.26 % [0.62–1.56], p > 0.05).In conclusion, to prevent PR3-related autoimmunity, autoreactive PR3+B cells pass a stringent selection in the BM, and their removal by central tolerance checkpoint activity occurs mainly between T1-like/immature to T2-like/early transitional B cells of BMMC.

Influence of Secondary Metabolites According to Maturation of Perilla (Perilla frutescens) on Respiratory Protective Effect in Fine Particulate Matter (PM2.5)-Induced Human Nasal Cell.

Fine particulate matter (PM2.5) exposure worsens chronic respiratory diseases through oxidative stress and inflammation. Perilla frutescens (L.) has potential respiratory protective properties, but the impact of growth stages on its beneficial metabolites is unclear. We aimed to evaluate how different growth stages affect phenolic acids, flavonoids, and polycosanols in perilla seeds and flowers and their efficacy in countering PM2.5-induced damage. Perilla seeds and flowers from five varieties at 10, 20, 30, and 40 days post-flowering were analyzed for metabolite content. Their antioxidant, anti-inflammatory, and respiratory protective effects were tested in RPMI 2650 cells. Our findings indicated that perilla flowers contained higher levels of functional components than seeds and exhibited significant variation with maturation. Phenolic acids of perilla flowers were highest at the early stages of maturation after flowering. However, individual flavones of perilla flowers were the highest at the late maturation stages after flowering. Extracts from perilla flowers harvested 20 days after flowering exhibited significant respiratory protection, effectively inhibiting inflammatory cytokines, mucus secretion, and oxidative stress markers. In conclusion, the flower parts of perilla, particularly those harvested 20 days after flowering, are useful materials for obtaining phenolic compounds, including rosmarinic acid, with high antioxidant and respiratory enhancement effects.

Genetic iron overload aggravates, and pharmacological iron restriction improves, MDS pathophysiology in a preclinical study

AbstractAlthough iron overload is a common feature in myelodysplastic syndromes (MDSs), it remains unclear how iron excess is detrimental for disease pathophysiology. Taking advantage of complementary approaches, we analyzed the impact of iron overload and restriction achieved through genetic activation of ferroportin (FPN) via the C326S mutation (FPNC326S) and pharmacologic inhibition (vamifeport) of the iron exporter FPN, respectively, in a MDS mouse model. Although FPNC326S-induced iron overload did not significantly improve the late stages of erythroid maturation, vamifeport-mediated iron restriction ameliorated anemia and red blood cell maturation in MDS mice, through the reduction of oxidative stress and apoptosis in erythroid progenitors. Iron overload aggravated, and restriction alleviated, reactive oxygen species formation, DNA damage, and cell death in hematopoietic stem and progenitor cells, resulting in altered cell survival and quality. Finally, myeloid bias, indicated by expanded bone marrow myeloid progenitors and circulating immature myeloid blasts, was exacerbated by iron excess and attenuated by iron restriction. Overall, vamifeport treatment resulted in improved anemia and significant survival increment in MDS mice. Interestingly, the combined therapy with vamifeport and the erythroid maturation agent luspatercept has superior effect in improving anemia and myeloid bias as compared with single treatments and offers additive beneficial effects in MDS. Our results prove, to our knowledge, for the first time in a preclinical model, that iron plays a pathologic role in transfusion-independent MDS. This is likely aggravated by transfusional iron overload, as suggested by observations in the FPNC326SMDS model. Ultimately, the beneficial effects of pharmacologic FPN inhibition uncovers the therapeutic potential of early prevention of iron toxicity in transfusion-independent MDS.

Study on the Changes in the Microbial Community in Rhizosphere Soil of Blueberry Plants at Different Growth Stages

In order to clarify the relationship between mineral nutrients and rhizosphere microorganisms at different growth and development stages of blueberry (Vaccinium spp.), this work studied the dynamic changes in element content and microbial quantity in different parts of blueberry plants. The test material was a 12-year-old half-highbush blueberry variety (‘Beilu’). The changes in the mineral nutrient elements in leaves, branches and the soil of blueberry plants were studied at the full bloom stage (T1), green fruit stage (T2), mature stage (T3) and late mature stage (T4), and the correlations of the average contents of mineral elements in the four periods were studied. The bacterial community in the rhizosphere soil was determined and analyzed using 16S rRNA high-throughput sequencing technology. The results showed that the changes in other mineral elements in various parts of blueberry plants varied in different periods. Nitrogen (N) showed a downward trend in branches, leaves and soil, especially in leaves (p &lt; 0.05). The N contents in T2, T3 and T4 decreased by 9.9%, 26.4% and 29.9%, respectively. The N contents in the leaves and branches showed a downward trend at different growth stages, especially in leaves. The phosphorus (P) content in leaves showed a trend of increasing first and then decreasing, while it continued to increase in branches. The content of potassium (K) in leaves changed significantly, where it increased first and then decreased. The content of calcium (Ca) in leaves decreased first and then increased, while the content of magnesium (Mg) in branches and leaves decreased first and then increased, and the relative change was significant. The contents of iron (Fe) and zinc (Zn) in leaves decreased first and then increased, while the contents of manganese (Mn) and copper (Cu) were relatively stable. Cu decreased first and then increased in leaves and soil, and it increased first and then decreased in branches. The mineral nutrients in different growth stages of blueberry showed significant correlation in leaves, branches and soil. Mn in leaves was significantly positively correlated with P, Ca, Mg, Mn, Cu and Zn in soil (p &lt; 0.01). Nitrogen and calcium in leaves were significantly correlated with manganese and phosphorus in soil, respectively. Ca in branches was significantly positively correlated with N and K in soil and was significantly positively correlated with Zn in soil (p &lt; 0.01). Magnesium was significantly negatively correlated with iron in soil. The bacterial community structure of the blueberry rhizosphere soil changed significantly over time (p &lt; 0.05), and the relative abundance showed the following trend: T4 &gt; T2 &gt; T3 &gt; T1. At the phylum level, Proteobacteria, Acidobacteria, Actinobacteria, Chloroflexi and Verrucomicrobia were the dominant bacteria in different periods. Candidatus solibacter and Bryobacter were significantly higher in T1 and T3 than in T1 and T4. Bradyrhizobium flora increased significantly at T3. Sphingomonas increased significantly at T1 (p &lt; 0.05).

Tectonic Physical Simulation Experiments: Evolution from Qualitative Exploration to Quantitative Analysis and Future Prospects

This review synthesizes the historical development, research methodologies, and current scientific issues of tectonic physical simulation experiments, while also looking forward to future research directions in the field. Since the early 19th century when James Hall first simulated fold formation, the field has undergone a transition from qualitative studies to quantitative analysis. We analyze key research and technological advancements across the early exploration, mid-term development, and late maturation stages, with a particular focus on the introduction and application of the similarity principles, as well as the incorporation of Particle Image Velocimetry (PIV) technology. Despite significant progress, challenges remain in the selection of experimental materials, precise application of similarity principles, and experimental precision. Future research should explore new materials, interdisciplinary collaboration, and the application of big data technology to enhance the accuracy and reliability of simulation experiments.

Comparative Transcriptomic and Lipidomic Analysis of Fatty Acid Accumulation in Three Camellia oleifera Varieties During Seed Maturing.

Camellia oleifera, a major woody oil crop in China, produces tea oil rich in unsaturated fatty acids, earning it names like liquid gold and eastern olive oil. This study provides an integrated investigation of the transcriptome and lipidome within seeds at the maturing process across three C. oleifera varieties, revealing a significant relationship between fatty acid production and genes involved in lipid synthesis. Through transcriptomic analysis, 26,344 genes with varied expression were found. Functional enrichment analysis highlighted that pathways related to starch and sucrose metabolism, plant hormone signal transduction, and lipid accumulation were highly enriched among the differentially expressed genes. Coordinated high expression of key genes (ACCase, KAS I, KAS II, KAS III, KAR, HAD, EAR, SAD, LPAAT, LACS, DGAT, PDAT) during the late maturation stage contributes largely to high oil content. Additionally, expression variations of SAD and FADs among different varieties were explored. The analysis suggests that high expression of genes such as FAD3, FAD7, and FAD8 notably increased linolenic acid content. This research provides new insights into the molecular mechanisms of oil biosynthesis in C. oleifera, offering valuable references for improving yield and quality.

Plasmablast response during acute SARS-CoV-2 infection

Plasmablasts are a population of short-lived B cells that appear in the circulation shortly after vaccination and during acute infection. Plasmablasts are formed from resting B lymphocytes, from which they differ in their ability to secrete antibodies, making them similar to plasma cells. Plasmablasts are terminally differentiated cells that can form at various nodes and branches of the B cell response. The plasmablast response is an indicator of the success of vaccination and also helps in predicting antibody levels after recovery or vaccination. However, the definition and classification of plasmablasts faces great experimental and theoretical difficulties. The aim of the work was to determine the characteristics of the plasmablast response during acute SARS-CoV-2 infection. The study included patients (n = 28) with a severe form of COVID-19. Blood sampling was carried out once on the 10–18th day from the moment of hospitalization. B cells were isolated by immunomagnetic separation. Cells were phenotyped using flow cytometry. Secretion of IgM and IgG was determined by ELISpot method. B cell subsets were isolated using a cell sorter. Patients with COVID-19 had an approximately fourfold increase in total plasmablast levels compared to healthy donors. An even more pronounced excess over the negative control was observed for RBD-specific plasmablasts. In terms of their composition, plasmablasts were one third IgM⁺ cells. This distribution between B-cell BCR receptor isotypes was consistent with the primary nature of the immune response in COVID-19. Approximately a third of plasmablasts carried the CD138 antigen. CD138 marker is characteristic of the late stage of plasmablast maturation and is also found on plasma cells. The CD27+CD38⁺ population was divided according to the expression of the CD138 antigen. Using the ELISpot method, we have shown that a significant portion of circulating plasmablasts are antibody-secreting cells. Among circulating plasmablasts, both early and late plasmablasts can be distinguished, which are characterized by the absence of a surface BCR, but which carry the CD138 antigen. Determining how plasmablasts relate to other B cell populations is of paramount importance for the development of new treatments for COVID-19 and for the creation of promising vaccines against SARS-CoV-2 infection.

Ultrastructure of the Spermiogenesis in Halyomorpha halys (Hemiptera: Pentatomidae): X-Irradiation and New Insights on the Centriolar Region Organization.

Halyomorpha halys (Heteroptera: Pentatomidae) is an insect pest native to Asia that has spread over the last two decades to most of the North America, parts of South America, Europe and North Africa. Its impact is significant as it can feed on more than 300 host plants, rendering affected fruits and vegetable crops unsellable or of lower quality. Various chemical and biological methods have been used to control this pest, with varying degrees of success. The sterile insect technique (SIT) is a pest control method involving the sterilization of insects via ionizing radiation and their subsequent mass release into the field. In the present contribution, the spermiogenesis of H. halys was studied from an ultrastructural point of view in both irradiated and non-irradiated adult males. In both cases, we observed ultrastructural characteristics typical of hemipteran sperm cells: bridges connecting the mitochondrial derivatives and the axonemal microtubules, the absence of accessory bodies, and the presence of two or three crystalline inclusions within the mitochondrial derivatives, an acrosome composed of tightly packed tubules, and an atypical, plaque-shaped microtubular organizing center (MTOC) in the centriolar region. Moreover, in the same region, we seldom observed the presence of two centrioles in the spermatids, one of which disappeared at a later stage of maturation. This feature is a novelty for insect spermiogenesis. The cysts of irradiated adults were not all uniformly affected by the radiation. However, irradiated cysts sometimes exhibited a general disorganization of sperm arrangement, incomplete divisions of sperm cells resulting in multiple copies of the same organelle within the same cell, failure to reabsorb the cytoplasm, and the lack of axonemes. Finally, rod-shaped viruses or virus-like particles were observed in vasa deferentia independently of irradiation.

Morphological and Molecular Characteristics of Perineuronal Nets in the Human Prefrontal Cortex-A Possible Link to Microcircuitry Specialization.

Perineuronal nets (PNNs) are a type of extracellular matrix (ECM) that play a significant role in synaptic activity and plasticity of interneurons in health and disease. We researched PNNs' regional and laminar representation and molecular composition using immunohistochemistry and transcriptome analysis of Brodmann areas (BA) 9, 14r, and 24 in 25 human postmortem brains aged 13-82 years. The numbers of VCAN- and NCAN-expressing PNNs, relative to the total number of neurons, were highest in cortical layers I and VI while WFA-binding (WFA+) PNNs were most abundant in layers III-V. The ECM glycosylation pattern was the most pronounced regional difference, shown by a significantly lower proportion of WFA+ PNNs in BA24 (3.27 ± 0.69%) compared to BA9 (6.32 ± 1.73%; P = 0.0449) and BA14 (5.64 ± 0.71%; P = 0.0278). The transcriptome of late developmental and mature stages revealed a relatively stable expression of PNN-related transcripts (log2-transformed expression values: 6.5-8.5 for VCAN and 8.0-9.5 for NCAN). Finally, we propose a classification of PNNs that envelop GABAergic neurons in the human cortex. The significant differences in PNNs' morphology, distribution, and molecular composition strongly suggest an involvement of PNNs in specifying distinct microcircuits in particular cortical regions and layers.

Assembling a Coculture System to Prepare Highly Pure Induced Pluripotent Stem Cell-Derived Neurons at Late Maturation Stages.

Generation of human induced pluripotent stem cell (hiPSC)-derived motor neurons (MNs) offers an unprecedented approach to modeling movement disorders such as dystonia and amyotrophic lateral sclerosis. However, achieving survival poses a significant challenge when culturing induced MNs, especially when aiming to reach late maturation stages. Utilizing hiPSC-derived motor neurons and primary mouse astrocytes, we assembled two types of coculture systems: direct coculturing of neurons with astrocytes and indirect coculture using culture inserts that physically separate neurons and astrocytes. Both systems significantly enhance neuron survival. Compared with these two systems, no significant differences in neurodevelopment, maturation, and survival within 3 weeks, allowing to prepare neurons at maturation stages. Using the indirect coculture system, we obtained highly pure MNs at the late mature stage from hiPSCs. Transcriptomic studies of hiPSC-derived MNs showed a typical neurodevelopmental switch in gene expression from the early immature stage to late maturation stages. Mature genes associated with neurodevelopment and synaptogenesis are highly enriched in MNs at late stages, demonstrating that these neurons achieve maturation. This study introduces a novel tool for the preparation of highly pure hiPSC-derived neurons, enabling the determination of neurological disease pathogenesis in neurons at late disease onset stages through biochemical approaches, which typically necessitate highly pure neurons. This advancement is particularly significant in modeling age-related neurodegeneration.

Spinal motor neuron development and metabolism are transcriptionally regulated by Nuclear Factor IA.

Neural circuits governing all motor behaviors in vertebrates rely on the proper development of motor neurons and their precise targeting of limb muscles. Transcription factors are essential for motor neuron development, regulating their specification, migration, and axonal targeting. While transcriptional regulation of the early stages of motor neuron specification is well-established, much less is known about the role of transcription factors in the later stages of maturation and terminal arborization. Defining the molecular mechanisms of these later stages is critical for elucidating how motor circuits are constructed. Here, we demonstrate that the transcription factor Nuclear Factor-IA (NFIA) is required for motor neuron positioning, axonal branching, and neuromuscular junction formation. Moreover, we find that NFIA is required for proper mitochondrial function and ATP production, providing a new and important link between transcription factors and metabolism during motor neuron development. Together, these findings underscore the critical role of NFIA in instructing the assembly of spinal circuits for movement.

Single-neuron analysis of aging-associated changes in learning reveals impairments in transcriptional plasticity.

The molecular mechanisms underlying age-related declines in learning and long-term memory are still not fully understood. To address this gap, our study focused on investigating the transcriptional landscape of a singularly identified motor neuron L7 in Aplysia, which is pivotal in a specific type of nonassociative learning known as sensitization of the siphon-withdraw reflex. Employing total RNAseq analysis on a single isolated L7 motor neuron after short-term or long-term sensitization (LTS) training of Aplysia at 8, 10, and 12 months (representing mature, late mature, and senescent stages), we uncovered aberrant changes in transcriptional plasticity during the aging process. Our findings specifically highlight changes in the expression of messenger RNAs (mRNAs) that encode transcription factors, translation regulators, RNA methylation participants, and contributors to cytoskeletal rearrangements during learning and long noncoding RNAs (lncRNAs). Furthermore, our comparative gene expression analysis identified distinct transcriptional alterations in two other neurons, namely the motor neuron L11 and the giant cholinergic neuron R2, whose roles in LTS are not yet fully elucidated. Taken together, our analyses underscore cell type-specific impairments in the expression of key components related to learning and memory within the transcriptome as organisms age, shedding light on the complex molecular mechanisms driving cognitive decline during aging.

Nature and occurrence, geochemical characteristics, and families of the crude oils in Sirt Basin, Libya: Implication for super rift basin petroleum system

In this study, we investigated the nature and characteristics of petroleum fluids in a super-global basin situated in the central north of Libya. With over 100 discovered fields (comprising oil and gas), this study aimed to understand the basin's petroleum accumulation mechanism (PAM), thereby shedding light on the factors contributing to significant petroleum discoveries in North Africa (Libya). The primary objective of this study was to provide a detailed regional refined oil family distribution and new insights into the total petroleum system (TPS) of the basin. This analysis was based on the integration of regional geology and organic geochemistry. Additionally, we utilized the physical properties of petroleum, such as API and sulphur content (%S), to obtain a better understanding of the regional physical nature of petroleum types and properties. Organic geochemical data for the basin fields were compiled, focusing on key biological marker and carbon isotope (‰ δ13C) data for saturated and aromatic compounds. These data were used to understand the origin, depositional source, and thermal maturity of the generated, migrated, and accumulated petroleum fluids. The study established specific types of organofacies and their relationships with petroleum phase characteristics, including type and quality, categorized into known groups (e.g., B, C, and D/E). Hierarchical cluster analysis (HCA) and map-based presentation approaches were used to determine the spatial types and distributions of oil and gas families in the basin. This was achieved by selecting the input parameters from various datasets and defining the significant parameters to characterize the distribution patterns. The findings indicate that the bulk fluid of the Sirt Basin primarily resembled Brent oil, which was characterized by a very low sulphur content (less than 1.4%). The API gravity ranged from 30 to 65, reflecting a diverse range of oil types within the basin. The crude oils in the basin were primarily derived from marine organofacies, predominantly from type B. This inference is supported by related biomarkers such as regular steranes and isoprenoids. Furthermore, the analysis of carbon isotopes provided a similar indication, with values ranging from −32 to −27 for ‰ δ13C for saturates and −31.2 to −25.4 ‰ δ13C for aromatic compounds. The thermal maturity biomarker ratio (Ts/Ts + Tm) of the Sirt Basin crude oils varied from 0.35 to 0.92, suggesting different levels of thermal maturity, typically ranging from the mid to late mature stages. This observation is consistent with the indication based on the 22S/22S + 22R ratio. The basin exhibited four dominant oil families and eight subfamilies with the same geochemical characteristics (HCA-based analysis), including early and later generations, relatively sulphurized oils, and condensate families.

Cytotoxicity of Quantum Dots in Receptor-Mediated Endocytic and Pinocytic Pathways in Yeast.

Despite the promising applications of the use of quantum dots (QDs) in the biomedical field, the long-lasting effects of QDs on the cell remain poorly understood. To comprehend the mechanisms underlying the toxic effects of QDs in yeast, we characterized defects associated with receptor-mediated endocytosis (RME) as well as pinocytosis using Saccharomyces cerevisiae as a model in the presence of cadmium selenide/zinc sulfide (CdSe/ZnS) QDs. Our findings revealed that QDs led to an inefficient RME at the early, intermediate, and late stages of endocytic patch maturation at the endocytic site, with the prolonged lifespan of GFP fused yeast fimbrin (Sac6-GFP), a late marker of endocytosis. The transit of FM1-43, a lipophilic dye from the plasma membrane to the vacuole, was severely retarded in the presence of QDs. Finally, QDs caused an accumulation of monomeric red fluorescent protein fused carbamoyl phosphate synthetase 1 (mRFP-Cps1), a vacuolar lumen marker in the vacuole. In summary, the present study provides novel insights into the possible impact of CdSe/ZnS QDs on the endocytic machinery, enabling a deeper comprehension of QD toxicity.

Sexual Dimorphism's impact on adipogenesis: A three-dimensional in vitro model treated with 17β-estradiol and testosterone

Using a three-dimensional (3-D) in vitro culture model, we report the dose dependent effect of 17β-estradiol and testosterone on the adipogenic differentiation and maturation of human adipose derived stem cells (hASCs) obtained from female and male patients. Considering sexual dimorphism, we expected male and female adipocytes to respond differently to the sex steroids. Both male and female hASC spheroids were exposed to 100 nM and 500 nM of 17β-estradiol and testosterone either at the beginning of the adipogenic maturation (Phase I) to discourage intracellular triglyceride accumulation or exposed after adipogenic maturation (Phase II) to reduce the intracellular triglyceride accumulation. The results show that 17β-estradiol leads to a dose dependent reduction in intracellular triglyceride accumulation in female hASC spheroids compared to the both untreated and testosterone-treated cells. Affirming our hypothesis, 17β-estradiol prevented intracellular triglyceride accumulation during Phase I, while it stimulated lipolysis during Phase II. PPAR-γ and adiponectin gene expression also reduced upon 17β-estradiol treatment in female cells. Interestingly, 17β-estradiol and testosterone had only a modest effect on the male hASC spheroids. Collectively, our findings suggest that 17β-estradiol can prevent fat accumulation in adipocytes during early and late stages of maturation in females.

Sec7 regulatory domains scaffold autoinhibited and active conformations

The late stages of Golgi maturation involve a series of sequential trafficking events in which cargo-laden vesicles are produced and targeted to multiple distinct subcellular destinations. Each of these vesicle biogenesis events requires activation of an Arf GTPase by the Sec7/BIG guanine nucleotide exchange factor (GEF). Sec7 localization and activity is regulated by autoinhibition, positive feedback, and interaction with other GTPases. Although these mechanisms have been characterized biochemically, we lack a clear picture of how GEF localization and activity is modulated by these signals. Here, we report the cryogenic electron microscopy structure of full-length Sec7 in its autoinhibited form, revealing the architecture of its multiple regulatory domains. We use functional experiments to determine the basis for autoinhibition and use structural predictions to produce a model for an active conformation of the GEF that is supported empirically. This study therefore elucidates the conformational transition that Sec7 undergoes to become active on the organelle membrane surface.

Spraying L-phenylalanine during fruit development alleviates chilling injury in harvested muskmelons by regulating membrane lipid metabolism

L-phenylalanine (L-Phe) is an aromatic essential amino acid. Although postharvest L-Phe treatment can alleviate chilling injury (CI) of fruit by scavenging excessive reactive oxygen species (ROS), there are no reports on whether L-Phe spraying during fruit development affects the CI of harvested muskmelon by regulating membrane lipid metabolism. In this study, plants and fruit of muskmelon (cv. Manao) were sequentially sprayed with 8 mM L-Phe four times at the young fruit stage, early expansion stage, late expansion stage and mature stage. The effect of L-Phe spraying during fruit development on CI of harvested muskmelon fruit was studied and to the related mechanism of membrane lipid metabolism was investigated. The results showed that L-Phe sprays activated phospholipase A2 (PLA2) and increased the content of unsaturated fatty acids such as linoleic acid, linolenic acid and oleic acid, and improved the double bond index of unsaturated fatty acids (DBI) in harvested muskmelons during cold storage. L-Phe sprays inhibited the phospholipase C (PLC) and phospholipase D (PLD), increased the content of phosphatidylinositol (PI) and phosphatidylcholine (PC), but decreased the content of phosphatidic acid (PA) in harvested muskmelons during cold storage. In addition, L-Phe sprays inhibited lipoxygenase (LOX), reduced malondialdehyde (MDA) levels and cell membrane permeability, and effectively reduced the CI index of harvested muskmelons during cold storage. Taken together, L-Phe sprays during fruit development alleviated CI in harvested muskmelons by regulating membrane lipid metabolism.

Molecular and Carbon Isotopic Compositions of Crude Oils from the Kekeya Area of the Southwest Depression, Tarim Basin: Implications for Oil Groups and Effective Sources

Molecular and stable carbon isotopic compositions of 32 crude oils from the Kekeya area of the Southwest Depression, Tarim Basin, were analyzed comprehensively to clarify oil groups and trace oil sources. The results indicate that lacustrine shale sequences within the Upper-Middle Permian Pusige Formation (P3–2p) are the major effective oil sources; the thermal maturation effects exert the crucial impact on geochemical compositions of crude oils. In the Kekeya structural belt, crude oils produced from the Lower-Neogene, Middle-Paleogene and Middle-Cretaceous sandstone reservoirs were generated mainly from deeply buried P3–2p at the late-to-high maturity stage. These condensates are depleted in terpanes, steranes and triaromatic steranes and enriched in adamantanes and diamantanes. The evaluated thermal maturity levels of crude oils by terpanoids and steranes are generally lower than that of diamondoids, implying at least two phases of oil charging. In the Fusha structural belt, oils produced from the Lower-Jurassic reservoirs (J1s) of Well FS8 were generated from the local P3–2p at the middle to late mature stage. On the contrary, these oils are relatively rich in molecular biomarkers such as terpanes and steranes and depleted in diamondoids with only adamantanes detectable. The P3–2p-associated oils can migrate laterally from the Kekeya to Fusha structural belt, but not to the location of Well FS8. The Middle-Lower Jurassic (J1–2) lacustrine shales as the major oil sources are limited to the area around Well KS101 in the Kekeya structural belt. Crude oils originated from J1–2 and P3–2p can mix together within the Cretaceous reservoirs of Well KS101 by presenting the concurrence of high concentrations of terpane and sterane biomarkers and diamondoids as well as 2–4% 13C-enriched n-alkanes than those of P3–2p derived oils. This study provides a better understanding of hydrocarbon sources and accumulation mechanisms and hence petroleum exploration in this region.

The Role of Chorein Deficiency in Late Spermatogenesis.

VPS13A, also known as chorein, whose loss of function causes chorea-acanthocytosis (ChAc), is characterized by Huntington's-disease-like neurodegeneration and neuropsychiatric symptoms in addition to acanthocytosis in red blood cells. We previously reported that ChAc-model mice with a loss of chorein function exhibited male infertility, with asthenozoospermia and mitochondrial dysmorphology in the spermatozoa. Here, we report a novel aspect of chorein dysfunction in male fertility, particularly its role in spermatogenesis and mitochondrial integrity. An increase in anti-malondialdehyde antibody immunoreaction within the testes, predominantly observed at the advanced stages of sperm formation in chorein-deficient mice, suggests oxidative stress as a contributing factor to mitochondrial dysfunction and impaired sperm maturation. The chorein immunoreactivity in spermatids of wild-type mice accentuates its significance in sperm development. ChAc-model mice exhibit mitochondrial ultrastructural abnormalities, specifically during the late stages of sperm maturation, suggesting a critical timeframe for chorein's action in spermiogenesis. We observed an increase in TOM20 protein levels, indicative of disrupted mitochondrial import mechanisms. The concurrent decrease in metabolic enzymes such as IDH3A, LDHC, PGK2, and ACAT1 suggests a complex chorein-mediated metabolic network that is essential for sperm vitality. Additionally, heightened separation of cytoplasmic droplets from sperm highlights the potential membrane instability in chorein-deficient spermatozoa. Metabolomic profiling further suggests a compensatory metabolic shift, with elevated glycolytic and TCA-cycle substrates. Our findings suggest that chorein is involved in anti-ferroptosis and the maturation of mitochondrial morphology in the late stages of spermatogenesis, and its deficiency leads to asthenozoospermia characterized by membrane instability, abnormal cytosolic glycolysis, abnormal mitochondrial function, and a disrupted TCA cycle. Further analyses are required to unravel the molecular mechanisms that directly link these findings and to elucidate the role of chorein in spermatogenesis as well as its broader implications.

Drainage Morphometric analysis of Yagachi watershed area, Karnataka State, India

The Yagachi River watershed in Karnataka State has been chosen for a thorough analysis to recognize the drainage system, morphometric features, and vulnerability of the watershed area to erosion. As a prerequisite to the analysis of morphometric features utilizing ArcGIS software, the stream networks and sub-watersheds (viz., SW01, SW02, SW03 and SW04) were delineated by making use of topographic sheets and the Digital Elevation Model (DEM). Yagachi watershed covers an area of 551.45 sq. km and observed predominant drainage patterns are sub-parallel and dendritic with sixth-order drainage. Higher stream orders (U=6), implying greater surface runoff and sediment load, and low mean stream length values in the upper reaches, signifying youthful morphological development and strong erosion potential, are characteristics of streams in the watershed. Drainage density values (1.262 to 1.930 km/km2), particularly at upper reaches in the NW part of the watershed, fine to very fine drainage texture values (7.572 and 8.337), moderate to high values of length of overland flow (Lg) and constant of channel maintenance (CCM) indicate steep to moderate slopes, fairly significant surface runoff, and high erosive power of the streams and greater sediment load. The elongated form of the watershed is shown by the computed lower form factor (Ff) and elongation ratio (Re) values. Relief characteristics of the watershed area, although suggest that the study area is vulnerable to erosion and in youth stage, in reality, the area is characterised more by the features of the late mature stage of landform development. The observed anomaly is attributed to the mountain-plain environment as the steeply sloped hill ranges of Bababudan formations are located in the northwestern parts of the Yagachi watershed area. However, the sub-watershed SW03 with high stream length, drainage density and relief value with fine drainage texture is relatively more susceptible to erosion.