Molecular Mechanisms Research Articles

Understanding the Role of the SMN Complex Component GEMIN5 and Its Functional Relationship with Demethylase KDM6B in the Flunarizine-Mediated Neuroprotection of Motor Neuron Disease Spinal Muscular Atrophy

Dysregulated RNA metabolism caused by SMN deficiency leads to motor neuron disease spinal muscular atrophy (SMA). Current therapies improve patient outcomes but achieve no definite cure, prompting renewed efforts to better understand disease mechanisms. The calcium channel blocker flunarizine improves motor function in Smn-deficient mice and can help uncover neuroprotective pathways. Murine motor neuron-like NSC34 cells were used to study the molecular cell-autonomous mechanism. Following RNA and protein extraction, RT-qPCR and immunodetection experiments were performed. The relationship between flunarizine mRNA targets and RNA-binding protein GEMIN5 was explored by RNA-immunoprecipitation. Flunarizine increases demethylase Kdm6b transcripts across cell cultures and mouse models. It causes, in NSC34 cells, a temporal expression of GEMIN5 and KDM6B. GEMIN5 binds to flunarizine-modulated mRNAs, including Kdm6b transcripts. Gemin5 depletion reduces Kdm6b mRNA and protein levels and hampers responses to flunarizine, including neurite extension in NSC34 cells. Moreover, flunarizine increases the axonal extension of motor neurons derived from SMA patient-induced pluripotent stem cells. Finally, immunofluorescence studies of spinal cord motor neurons in Smn-deficient mice reveal that flunarizine modulates the expression of KDM6B and its target, the motor neuron-specific transcription factor HB9, driving motor neuron maturation. Our study reveals GEMIN5 regulates Kdm6b expression with implications for motor neuron diseases and therapy.

Transcriptome Analysis of Differentially Expressed Genes and Molecular Pathways Involved in C2C12 Cells Myogenic Differentiation.

Muscles are essential tissues responsible for movement, stability, and metabolism, playing a crucial role in human health and well-being. A comprehensive understanding of muscle differentiation processes is imperative for combating muscle degenerative diseases such as muscular dystrophy. In this study, C2C12 cells were induced to differentiate into myotubes in vitro. Phenotypic changes were observed utilizing Gimsa and immunofluorescent staining techniques. RNA sequencing was conducted at distinct time points (0, 2, 4, and 7days) during the differentiation process. To elucidate the underlying molecular mechanisms, differential expression analysis, gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and Gene Set Enrichment Analysis (GSEA) were performed. Soft clustering of time series gene expression was employed to establish the expression patterns of differentially expressed genes (DEGs) at various time points during myogenesis. Additionally, quantitative reverse transcription PCR was utilized to validate gene expression from RNA-seq data at the mRNA level. Throughout the myogenic differentiation of C2C12 cells, notable morphological changes were observed, with myoblasts forming multinucleated myotubes by day 4 and plump elongated structures by day 7. Gene expression analysis revealed a substantial increase in DEGs as differentiation progressed, with a significant rise in DEGs from day 0 to day 7. Enrichment analysis highlighted key biological processes and pathways involved, including signal transduction and immune system processes, as well as pathways like chemokine and calcium signaling. Noise-robust soft clustering identified distinct temporal gene expression patterns, categorizing genes into upregulated, downregulated, and biphasic response clusters. The MYH family exhibited diverse expression changes, with Myh3, Myh13, Myh6, Myh7, Myh2, Myh8, Myh14, Myh7b, Myh1, and Myh4 upregulated, Myh10, Myh9, and Myh12 downregulated. Key transcription factors displayed dynamic expression patterns, which was crucial for the regulation of myoblast differentiation. A comprehensive and dynamic transcriptomic analysis of the C2C12 myoblast differentiation process has significantly enhanced our understanding of the key genes and biological pathways involved in myogenesis.

Peroxisome proliferator-activated receptor δ suppresses the cytotoxicity of CD8+ T cells by inhibiting RelA DNA binding activity.

The molecular mechanisms regulating CD8+ cytotoxic T lymphocytes (CTLs) are not fully understood. Here, we show that the peroxisome proliferator-activated receptor ƍ (PPAR-δ) suppresses CTL cytotoxicity by inhibiting RelA DNA binding. Treatment of ApcMin/+ mice with the PPAR-δ agonist GW501516 reduced the activation of normal and tumor-associated intestinal CD8+ T cells and increased intestinal adenoma burden. PPAR-δ knockout or knockdown in CTLs increased their cytotoxicity against colorectal cancer cells, whereas overexpression of PPAR-δ or agonist treatment decreased it. Correspondingly, perforin, granzyme B, and interferon γ (IFN-γ) protein and mRNA levels were higher in PPAR-δ knockout or knockdown CTLs and lower in PPAR-δ overexpressing or agonist-treated CTLs. Mechanistically, we found that PPAR-δ binds to RelA, interfering with RelA-p50 heterodimer formation in the nucleus, thereby inhibiting its DNA binding in CTLs. Thus, PPAR-δ is a critical regulator of CTL effector function.

The protective role of RACK1 in hepatic ischemia‒reperfusion injury-induced ferroptosis.

Although ferroptosis plays a crucial role in hepatic ischemia‒reperfusion injury (IRI), the molecular mechanisms underlying this process remain unclear. We aimed to explore the potential involvement of the receptor for activated C kinase 1 (RACK1) in hepatic IRI-triggered ferroptosis. Using hepatocyte-specific RACK1 knockout mice and alpha mouse liver 12 (AML12) cells, we conducted a series of in vivo and in vitro experiments. We found that RACK1 has a protective effect on hepatic IRI-induced ferroptosis. Specifically, RACK1 was found to interact with AMPKα through its 1-93 amino acid (aa) region, which facilitates the phosphorylation of AMPKα at threonine 172 (Thr172), ultimately exerting an antiferroptotic effect. Furthermore, the long noncoding RNA (lncRNA) ZNFX1 Antisense 1 (ZFAS1) directly binds to aa 181-317 of RACK1. ZFAS1 has a dual impact on RACK1 by promoting its ubiquitin‒proteasome-mediated degradation and inhibiting its expression at the transcriptional level, which indirectly exacerbates hepatic IRI-induced ferroptosis. These findings underscore the protective role of RACK1 in hepatic IRI-induced ferroptosis and showcase its potential as a prophylactic target for hepatic IRI mitigation.

Characterizing m6A modification factors and their interactions in colorectal cancer: implications for tumor subtypes and clinical outcomes

BackgroundThe study aims to comprehensively combine colorectal cancer data cohorts in order to analyze the effects of various DNA methylation-coding genes on colorectal cancer patients. The annual incidence and mortality of colorectal cancer are very high, and there are no effective treatments for advanced colorectal cancer. DNA methylation is a method widely used to regulate epigenetics in the molecular mechanism study of tumors.MethodThree single-cell cohorts GSE166555, GSE146771, and EMTAB8107, and five transcriptome cohorts GSE17536, GSE39582, GSE72970, and TCGA-CRC (TCGA-COAD and TCGA-READ) were applied in this study. 2 erasers (ALKBH5 and FTO), There are 7 writers (METTL3, METTL14, WTAP, VIRMA, RBM15, RBM15B, and ZC3H13) and 11 readers (YTHDC1, IGF2BP1, IGF2BP2, IGF2BP3, YTHDF1, YTHDF3, YTHDC2, and HNRNPA2B1, YTHDF2, HNRNPC and RBMX), a total of 20 M6A regulators, were used as the basis of the dataset in this study and were applied to the construction of molecular typing and prognostic models. Drugs that are differentially sensitive in methylation-regulated gene-related prognostic models were identified using the ConsensusClusterPlus package, which was also used to identify distinct methylation regulatory expression patterns in colorectal cancer and to model the relationship between tissue gene expression profiles and drug IC50 values. Finally, TISCH2 assessed which immune cells were significantly expressed with M6A scores. The immunosuppression of M6A methylation is spatially explained.ResultsThis study used data from 583 CRC patients in the TCGA-CRC cohort. Firstly, the mutation frequency and CNV variation frequency of 20 m6A modification-related factors were analyzed, and the corresponding histogram and heat map were drawn. The study next analyzed the expression variations between mutant and wild forms of the VIRMA gene and explored differences in the expression of these variables in tumor and normal tissues. In addition, the samples were divided into different subgroups by molecular clustering method based on m6A modification, and each subgroup’s expression and clinicopathological characteristics were analyzed. Finally, we compared prognostic differences, tumor microenvironment (TME) characteristics, immune cell infiltration, and gene function enrichment among different subpopulations. We also developed a colorectal cancer m6A-associated gene signature and validated its prognostic effects across multiple cohorts. Finally, using single-cell RNA sequencing data, we confirmed that tumor cells show elevated expression of m6A-related gene signatures.DiscussionThis study explored the mutation frequency, expression differences, interactions, molecular clustering, prognostic effect, and association with tumor characteristics of m6A modification-related factors in CRC and validated them at the single-cell level. These results clarify the association between m6A alteration and colorectal cancer (CRC) and offer important insights into the molecular recognition and management of cancer.

Loss of CCDC188 causes male infertility with defects in the sperm head-neck connection in mice.

Acephalic spermatozoa syndrome (ASS) represents a rare genetic and reproductive disease, which is defined as semen composed of mostly headless spermatozoa. The connecting piece in the neck region, also known as the head-to-tail coupling apparatus (HTCA), plays a crucial role in the tight linkage between the sperm head and tail. Dysfunction of this structure can lead to separation of sperm heads and tails, and male infertility. Using the mouse as an experimental model, several proteins have been identified as associated with the HTCA and disruption of these proteins causes acephalic spermatozoa. However, the molecular mechanism underlying this morphologic anomaly and HTCA remains elusive. In this study, we focused on coiled-coil domain containing 188 (Ccdc188), which shows testis-enriched expression. To elucidate the physiological role of CCDC188, we generated a knockout (KO) mouse line using the CRISPR/Cas9 system. Ccdc188 KO male mice were sterile, indicating that CCDC188 is indispensable for male fertility. Most Ccdc188-null spermatozoa were acephalic. Transmission electron microscopy revealed that while the sperm HTCA could assemble properly without CCDC188, the HTCA failed to attach to the nucleus during spermiogenesis, leading to sperm head and neck separation. In addition, we found almost all of the spermatozoa in the cauda epididymis lacked a mitochondrial sheath. Taken together, we demonstrated that CCDC188 plays a crucial role in forming a tight sperm head-neck junction.

Emerging fatal gout disease in Chinese goslings linked to acute kidney injury induced by novel goose astrovirus infection

A novel goose astrovirus (GAstV) has broken out across China in recent years, causing widespread damage to the poultry industry. In goslings infected with GAstV, the leading cause of death is visceral gout. However, our understanding of the mechanism of gout formation in GAstV infection is largely inadequate. The aim of this study was to examine the pathogenicity of a GAstV strain and explore the molecular mechanisms of visceral gout caused by viral infection in goslings. The virulent GAstV strain HR2105/1 was effectively isolated from the visceral tissue of goslings in gout-affected areas. The whole genome of the HR2105/1 strain was sequenced and analyzed. Subsequently, we established a gosling gout models with experimental GAstV infection. Finally, we conducted a study on the mechanism of GAstV induced acute kidney injury. Phylogenetic analysis of the complete genome sequence showed that it was closely related to the strain circulating in China since 2016, and it was grouped within the GAstV-1 cluster. The clinical signs were reproduced by experimental infection of healthy goslings with the isolated strain and were found to be similar to those reported in clinical cases. Moreover, the virus exhibits strong renal tropism. Infection with the GAstV strain HR2105/1 was found to cause acute kidney injury, as evidenced by increased levels of uric acid and creatinine as well as severe pathological damage. Mechanistic experiments with Masson and Picrosirius Red staining revealed fibrosis in renal tissues after GAstV infection. Furthermore, TUNEL staining revealed that GAstV infection triggered renal cell apoptosis. Additionally, RT-qPCR revealed that GAstV infection caused an excessive inflammatory response by upregulating the expression of IL-1β, IL-6, IL-10, TGF-β, and iNOS in renal tissues. Overall, our findings demonstrate that GAstV infection causes renal damage by inducing renal cell apoptosis, fibrosis, and excessive inflammatory response, which subsequently leads to hyperuricemia and lethal visceral gout formation. This is the first systematic study on the etiology of lethal gout in goslings caused by GAstV infection, and we believe that the findings can guide vaccine development and therapeutic targets for GAstV-associated renal diseases.

Dual role of the S5 segment in type 1 ryanodine receptor channel gating

The type 1 ryanodine receptor (RyR1) is a Ca2+ release channel in the sarcoplasmic reticulum that is essential for skeletal muscle contraction. RyR1 forms a channel with six transmembrane segments, in which S5 is the fifth segment and is thought to contribute to pore formation. However, its role in channel gating remains unclear. Here, we performed a functional analysis of several disease-associated mutations in S5 and interpreted the results with respect to the published RyR1 structures to identify potential interactions associated with the mutant phenotypes. We demonstrate that S5 plays a dual role in channel gating: the cytoplasmic side interacts with S6 to reduce the channel activity, whereas the luminal side forms a rigid structural base necessary for S6 displacement in channel opening. These results deepen our understanding of the molecular mechanisms of RyR1 channel gating and provide insight into the divergent disease phenotypes caused by mutations in S5.

Unraveling Morphological, Physiological, and Transcriptomic Alterations Underlying the Formation of Little Leaves in Phytoplasma-Infected Sweet Cherry Trees.

Phytoplasmas are minute phytopathogenic bacteria that induce excessive vegetative growth, known as witches'-broom (WB), in many infected plant species during the later stages of infection. The WB structure is characterized by densely clustered little (small) leaves, which are frequently accompanied by chlorosis (yellowing). The mechanisms behind the formation of little leaves within WB structures (LL-WB) are poorly understood. To address this gap, the LL-WB formation was extensively studied using sweet cherry virescence (SCV) phytoplasma-infected sweet cherry plants. Based on morphological examinations, signs of premature leaf senescence were observed in LL-WB samples, including reduced leaf size, chlorosis, and alterations in shape. Subsequent physiological analyses indicated decreased sucrose and glucose levels and changes in hormone concentrations in LL-WB samples. Additionally, the transcriptomic analysis revealed impaired ribosome biogenesis and DNA replication. As an essential process in protein production, the compromised ribosome biogenesis and the inhibited DNA replication led to cell cycle arrest, thus affecting leaf morphogenesis and further plant development. Moreover, the expression of marker genes involved in premature leaf senescence was significantly altered. These results indicate a complicated interplay between the development of leaves, premature leaf senescence, and the pathogen-induced stress responses in SCV phytoplasma-infected sweet cherry trees. The results of this study provide insight into understanding the underlying molecular mechanisms driving the formation of little leaves and interactions between plants and pathogens. The findings might help control phytoplasma diseases in sweet cherry cultivation.

A perspective on the time‐dependent structure and properties of amorphous polymer

AbstractA molecular mechanism of viscoelastic deformation is presented. Amorphous polymers are characterized as a heterogeneous network of nanoscale cells. A “cell” is a homogeneous region within the network. Each cell phase fluctuates between the glassy and elastomer states with a period τ. The values of τ vary from cell to cell over several orders of magnitude and are strong functions of temperature. Whether a given cell responds as glassy or elastomeric depends on the ratio between its period of phase fluctuation (τj) and the period of observation (1/f), where f is the test frequency. We express this ratio, the Deborah number, as (τj × f), and present equations for modulus and energy loss as functions of (τj × f). The condition (τj × f) = 1 defines the glass transition of a cell, which arises cell‐by‐cell over a range of temperature, or over a range of time under stress. Viscoelastic deformation occurs if a cell changes phase while under stress. Energy stored during glassy state deformation is lost if the cell fluctuates to the elastomeric state. Stress is out of phase with strain, because strain rate controls the level of stress in glassy cells between phase fluctuations.Highlights A molecular mechanism of viscoelasticity is presented that does not involve viscous flow. Amorphous polymer is a heterogeneous network of nanoscale cells. Cells fluctuate in phase between glassy and elastomeric states due to their size. Time‐dependent properties are caused by time‐dependent structure. Energy is lost when glass phase cells under stress fluctuate to the elastomer phase.

The androgen receptor in mesenchymal progenitors regulates skeletal muscle mass via Igf1 expression in male mice

Androgens exert their effects primarily by binding to the androgen receptor (AR), a ligand-dependent nuclear receptor. While androgens have anabolic effects on skeletal muscle, previous studies reported that AR functions in myofibers to regulate skeletal muscle quality, rather than skeletal muscle mass. Therefore, the anabolic effects of androgens are exerted via nonmyofiber cells. In this context, the cellular and molecular mechanisms of AR in mesenchymal progenitors, which play a crucial role in maintaining skeletal muscle homeostasis, remain largely unknown. In this study, we demonstrated expression of AR in mesenchymal progenitors and found that targeted AR ablation in mesenchymal progenitors reduced limb muscle mass in mature adult, but not young or aged, male mice, although fatty infiltration of muscle was not affected. The absence of AR in mesenchymal progenitors led to remarkable perineal muscle hypotrophy, regardless of age, due to abnormal regulation of transcripts associated with cell death and extracellular matrix organization. Additionally, we revealed that AR in mesenchymal progenitors regulates the expression of insulin-like growth factor 1 (Igf1) and that IGF1 administration prevents perineal muscle atrophy in a paracrine manner. These findings indicate that the anabolic effects of androgens regulate skeletal muscle mass via, at least in part, AR signaling in mesenchymal progenitors.

WISP1 and Macrophage Migration Inhibitory Factor in Respiratory Inflammation: Novel Insights and Therapeutic Potentials for Asthma and COPD

Recent advancements highlight the intricate interplay between the extracellular matrix (ECM) and immune responses, notably in respiratory diseases such as asthma and Chronic Obstructive Pulmonary Disease (COPD). The ECM, a dynamic structural framework within tissues, orches-trates a plethora of cellular processes, including immune cell behavior and tissue repair mecha-nisms. WNT1-inducible-signaling pathway protein 1 (WISP1), a key ECM regulator, controls immune cell behavior, cytokine production, and tissue repair by modulating integrins, PI3K, Akt, β-catenin, and mTOR signaling pathways. WISP1 also induces macrophage migration inhibitory factor (MIF) expression via Src kinases and epidermal growth factor receptor (EGFR) activation. MIF, through its wide range of activities, enhances inflammation and tissue restructuring. Rec-ognized for its versatile roles in regulating the immune system, MIF interacts with multiple immune components, such as the NLRP3 inflammasome, thereby sustaining inflammatory pro-cesses. The WISP1–MIF axis potentially unveils complex molecular mechanisms governing im-mune responses and inflammation. Understanding the intricate roles of WISP1 and MIF in the pathogenesis of chronic respiratory diseases such as asthma and COPD could lead to the identi-fication of novel targets for therapeutic intervention to alleviate disease severity and enhance patient outcomes.

Metabolome and Transcriptome Profiling Reveals Age-Associated Variations in Meat Quality and Molecular Mechanisms of Taihe Black-Bone Silky Fowls

Metabolome and Transcriptome Profiling Reveals Age-Associated Variations in Meat Quality and Molecular Mechanisms of Taihe Black-Bone Silky Fowls

Neuroprotective Effect of Codonopsis pilosula Polysaccharide on Aβ25-35-Induced Damage in PC12 Cells via the p38MAPK Signaling Pathways

Objectives: Plant polysaccharides have attracted increasing attention due to their high efficiency and low toxicity. Codonopsis pilosula polysaccharide (CPP) is an essential substance extracted from Codonopsis pilosula, known for its excellent antioxidant and neuroprotective effects. However, it is still unclear how CPP improves nerve protection and what its underlying molecular mechanisms are. This study aimed to investigate the neuroprotective effect of CPP on Aβ25-35-induced damage in PC12 cells and its underlying molecular mechanisms. Methods: The neuroprotective effect of CPP was evaluated using Aβ25-35-induced damage in pheochFfromocytoma (PC12) cells as an in vitro cell model. The cells were treated with CPP alone or in combination with SB203580 (an inhibitor of p38MAPK) in Aβ25-35 culture. The cell viability was assessed using a 3-(4,5-Dimethylthiazol-2-yl)-2,diphenyltetrazolium (MTT) assay. Furthermore, reactive oxygen species (ROS) were detected using flow cytometry. The production levels of intracellular superoxide dismutase (SOD), dismutase (SOD), glutathione (GSH), catalase (CAT), and malondialdehyFde (MDA) were determined using the colorimetric method. Annexin V-FITC and propidium iodide (PI) staining, as well as 33258 were performed using fluorescence microscopy. Moreover, the effect of adding SB203580 was studied to determine the changes in cell apoptosis induced by CPP treatment and Aβ25-35 induction. Results: The CPP markedly inhibited Aβ25-35-induced reduction in the viability and apoptosis of PC12 cells. CPP also reduced the Aβ25-35-induced increase in the expression of the apoptosis factors and the levels of free radicals (ROS and MDA) and reversed the Aβ25-35-induced suppression of antioxidant activity. Additionally, inhibition of p38MAPK via the addition of their antagonists reversed the observed anti-apoptosis effects of CPP. Conclusions: CPP can efficiently provide neuroprotection against Aβ25-35-induced damage in PC12 cells brought about via oxidation and apoptosis reactions, and the underlying mechanisms involve the p38MAPK pathways. Therefore, CPP could potentially be useful as a neuroprotective agent in natural medicine, pharmacy, and the food industry.

Efficacy and Mechanism of Alprostadil in Diabetes Mellitus Combined with Peripheral Atherosclerosis.

The aim is to investigate the clinical efficacy of Alprostadil in diabetes mellitus (DM) combined with peripheral atherosclerosis and to investigate the molecular mechanisms. Patients included 154 cases with DM combined with peripheral atherosclerosis and were divided into the conventional group (77 cases) and the Alprostadil group (77 cases). Both groups of patients were given conventional treatment, and the Alprostadil group was given Alprostadil treatment on the basis of the conventional group. The therapeutic efficacy and clinical symptom improvement were compared, and the adverse reactions were observed. An in vitro cell model was constructed using high glucose (HG) (50 mM) and oxidized low-density lipoprotein (50 μg/mL) treatment. The total effective rate of treatment in the Alprostadil group was higher than that in the conventional group. The biochemical indices of whole blood viscosity, plasma viscosity, erythrocyte pressure volume, and fibrinogen, as well as the level of inflammatory factors in the Alprostadil group were lower than those in the conventional group. The incidence rate of adverse reactions of Alprostadil administration was lower than that in the conventional group (P = .030). Alprostadil inhibited platelet aggregation and promoted platelet spreading. Alprostadil had an ameliorative effect on HG- and oxidized low-density lipoprotein cholesterol (ox-LDL)-induced human umbilical vascular endothelial cells (HUVECs), and promoted apoptosis and inflammatory response of HUVECs. Clinically, the use of Alprostadil as an adjunct to conventional therapy for the treatment of DM combined with peripheral atherosclerosis has high clinical efficacy. In addition, Alprostadil has a significant ameliorative effect on high glucose- and ox-LDL-induced HUVECs.

DeltaRex-G, tumor targeted retrovector encoding a CCNG1 inhibitor, for CAR-T cell therapy induced cytokine release syndrome

Cytokine release syndrome is a serious complication of chimeric antigen receptor-T cell therapy and is triggered by excessive secretion of inflammatory cytokines by chimeric T cells which could be fatal. Following an inquiry into the molecular mechanisms orchestrating cytokine release syndrome, we hypothesize that DeltaRex-G, a tumor targeted retrovector encoding a cytocidal CCNG1 inhibitor gene, may be a viable treatment option for corticosteroid-resistant cytokine release syndrome. DeltaRex-G received United States Food and Drug Administration Emergency Use Authorization to treat Covid-19-induced acute respiratory distress syndrome, which is due to hyperactivated immune cells. A brief administration of DeltaRex-G would inhibit a certain proportion of hyperactive chimeric T cells, consequently reducing cytokine release while retaining chimeric T cell efficacy.

High-quality chromosome-level genomic insights into molecular adaptation to low-temperature stress in Madhuca longifolia in southern subtropical China

BackgroundMadhuca longifolia, the energy-producing and medicinal tropical tree originally from southern India, faces difficulties in adapting to the low temperatures of late autumn and early winter in subtropical southern China, impacting its usability. Therefore, understanding the molecular mechanisms controlling the ability of this species to adapt to environmental challenges is essential for optimising horticulture efforts. Accordingly, this study aimed to elucidate the molecular responses of M. longifolia to low-temperature stress through genomic and transcriptomic analyses to inform strategies for its effective cultivation and utilisation in colder climates.ResultsHerein, the high-quality reference genome and genomic assembly for M. longifolia are presented for the first time. Using Illumina sequencing, Hi-C technology, and PacBio HiFi sequencing, we assembled a chromosome-level genome approximately 737.92 Mb in size, investigated its genomic features, and conducted an evolutionary analysis of the genus Madhuca. Additionally, using transcriptome sequencing, we identified 17,941 differentially expressed genes related to low-temperature response. Through bioinformatics analysis of the WRKY gene family, 15 genes crucial for M. longifolia low-temperature resistance were identified.ConclusionsThis research not only lays the groundwork for the successful ecological adaptation and cultivation of M. longifolia in China’s southern subtropical regions but also offers valuable insights for the genetic enhancement of cold tolerance in tropical species, contributing to their sustainable horticulture and broader industrial, medicinal, and agricultural use.

Can the male germline offer insight into mammalian brain size expansion?

Recent advances in single-cell transcriptomic data have greatly expanded our understanding of both spermatogenesis and the molecular mechanisms of male infertility. However, this growing wealth of data could also shed light on a seemingly unrelated biological problem: the genetic basis of mammalian brain size expansion throughout evolution. It is now increasingly recognized that the testis and brain share many cellular and molecular similarities including pivotal roles for the RAS/MAPK and PI3K/AKT/mTOR pathways, mutations in which are known to have a pronounced impact on cell proliferation. Most notably, in the stem cell lineages of both organs, new mutations have been shown to increase cellular output over time. These include 'selfish' mutations in spermatogonial stem cells, which disproportionately increase the proportion of mutant sperm, and-to draw a parallel-human-specific mutations in neural stem cells which, by increasing the number of neurons, have been implicated in neocortical expansion. Here we speculate that the origin for many 'expansion'-associated mutations is the male germline and that as such, a deeper understanding of the mechanisms controlling testicular turnover may yield fresh insight into the biology and evolution of the brain.

Genome-Wide Association Study of Resistance to Largemouth Bass Ranavirus (LMBV) in Micropterus salmoides

The disease caused by Largemouth bass ranavirus (LMBV) is one of the most severe viral diseases in largemouth bass (Micropterus salmoides). It is crucial to evaluate the genetic resistance of largemouth bass to LMBV and develop markers for disease-resistance breeding. In this study, 100 individuals (45 resistant and 55 susceptible) were sequenced and evaluated for resistance to LMBV and a total of 2,579,770 variant sites (SNPs-single-nucleotide polymorphisms (SNPs) and insertions–deletions (InDels)) were identified. A total of 2348 SNPs-InDels and 1018 putative candidate genes associated with LMBV resistance were identified by genome-wide association analyses (GWAS). Furthermore, GO and KEGG analyses revealed that the 10 candidate genes (MHC II, p38 MAPK, AMPK, SGK1, FOXO3, FOXO6, S1PR1, IL7R, RBL2, and GADD45) were related to intestinal immune network for IgA production pathway and FoxO signaling pathway. The acquisition of candidate genes related to resistance will help to explore the molecular mechanism of resistance to LMBV in largemouth bass. The potential polymorphic markers identified in this study are important molecular markers for disease resistance breeding in largemouth bass.

Functional characterization of protein SUMOylation in the miRNA transcription regulation during heat stress in Arabidopsis.

MicroRNAs (miRNAs) play an essential role as non-coding-RNA-type epigenetic regulators in response to high-temperature stress in plants. There are crucial roles for global transcriptional regulation under SUMO (small ubiquitin-related MOdifier) stress response (SSR). However, the molecular mechanisms underlying its downstream regulation remain unclear. In this study, SUMO-specific chromatin immunoprecipitation sequencing analysis detected specific binding in the promoter region of miRNAs under high-temperature stress. A correlation analysis between this binding and miRNA profiling revealed that the location of SUMO on the chromosome was correlated with the expression pattern of miRNAs, particularly miR398a and miR824a. In contrast, knockout mutants of the SSR-dependent SUMO E3 ligase SAP AND MIZ 1 in Arabidopsis exhibited opposing trends in target gene expression for the SUMO-related miRNAs compared to the wild type. Multi-omics correlation analyses identified 34 SUMO-candidate proteins that might be involved in the regulation of miRNA response to high-temperature stress. Therefore, we propose a potential model whereby high-temperature exposure induces nuclear entry of SUMO molecules, modifying specific transcription factors that bind to miRNA gene promoters and potentially regulate miRNA expression.