Search Results (72)

C. c. rubrofuscus is an economically important species in South China. During breeding, some individuals develop skeletal softening, but the underlying mechanisms remain unclear. In this study, five-month-old C. c. rubrofuscus were classified into a hard-bone group and a softened-bone group based on X-ray radiography. A systematic comparison was then conducted between the two groups, including analyses of external morphology, skeletal morphology, vertebral bone mineral density (BMD), calcium (Ca) and phosphorus (P) levels in serum and bone tissue, bone histology, and the expression of autophagy-related genes and proteins. The prevalence of the softened-bone phenotype was approximately 14% in the cultured population. Compared with the hard-bone group, the softened-bone group showed significantly lower vertebral BMD, significantly increased serum Ca levels, significantly decreased serum P levels, and markedly reduced Ca and P contents in bone tissue. In addition, varying degrees of deformity were observed in the ribs, caudal intermuscular spines, and urostyle. Histological examination further revealed severe skeletal malformations in the softened-bone group, characterized by irregular cortical bone thickness in the ribs and pterygiophores, together with a significantly reduced osteocyte density. Meanwhile, microtubule-associated protein 1 light chain 3 (LC3) levels were significantly increased, whereas sequestosome 1 (p62) levels were significantly decreased. The upregulated expression of autophagy-related genes suggested dysregulated autophagy, which may contribute to osteocyte loss. Collectively, these results indicate that the softened-bone phenotype in C. c. rubrofuscus is not associated with obvious changes in external body morphology. However, disrupted Ca-P homeostasis, together with altered autophagy, may impair osteocyte viability and bone mineralization, ultimately leading to bone softening and skeletal deformity. These findings provide a theoretical basis for further investigation of the mechanisms underlying bone softening and deformity in C. c. rubrofuscus and for the genetic improvement and selective breeding of cyprinid fish to reduce the occurrence of the softened-bone trait. Full article

Intracellular calcium (Ca²⁺) signaling is a central regulator of corticogenesis, governing haveneural stem cell behavior, fate transitions, neuronal migration, and circuit assembly. Beyond its canonical role as a second messenger, Ca²⁺ shapes cytoskeletal organization by modulating microtubule dynamics essential for mitotic spindle function, radial glial scaffold, nucleokinesis, and neurite extension. This review synthesizes evidence from in vivo, ex vivo, and in vitro studies to delineate Ca²⁺-dependent pathways and Ca²⁺-binding proteins that couple, within restricted Ca²⁺ microdomains in space and time, to microtubule regulation during mammalian cortical development. We highlight mechanistic nodes involving calmodulin, Ca²⁺/calmodulin-dependent kinases (CaMKs), S100 proteins, cadherins/protocadherins, centrins (CENs), and Ca²⁺ sensors such as STIM1 and calneurons, which collectively coordinate spindle orientation, progenitor division modes, radial migration, and neurite outgrowth. Finally, we discuss how perturbations in Ca²⁺-controlled cytoskeletal programs may contribute to abnormal cortical cytoarchitecture and neurodevelopmental disease. By integrating Ca²⁺ microdomain transients with microtubule control modules, this review provides a unified framework for understanding how Ca²⁺ orchestrates key cellular events during mammalian corticogenesis and propose that Ca²⁺ oscillatory codes are translated into direct or indirect microtubule/cytoskeletal remodeling transitions that determine neural stem cell fate, migration, and maturation, to accurately establish cortical architecture and function. Full article

Parkinson’s disease (PD) is a common neurodegenerative disorder marked by progressive loss of dopaminergic neurons in the substantia nigra pars compacta and the accumulation of Lewy bodies, intracellular inclusions enriched in α-synuclein. Synphilin-1 interacts with α-synuclein, localizes to Lewy bodies, and has been implicated in inclusion formation and neuroprotection in cellular and animal models; however, its physiological function in vivo remains poorly defined. Here, we generated and characterized a synphilin-1 knockout (Sph-1 KO) mouse by targeted genetic deletion of the Sph-1 locus and performed a comprehensive phenotyping battery including behavioral testing as well as biochemical, histological, structural, and ultrastructural analyses. Sph-1 KO mice survived to nearly two years of age and showed normal body weight, lifespan, motor performance, learning and memory, anxiety-like behavior, attention, and gross brain morphology. Western blot analyses indicated that levels of α-synuclein and synaptic proteins were largely unchanged. While outer mitochondrial membrane proteins were unaffected, the mitochondrial matrix protein HSP60 was reduced, consistent with altered mitochondrial proteostasis in the absence of synphilin-1. Strikingly, histochemical analyses, magnetic resonance imaging, and electron microscopy revealed early-onset hydrocephalus in Sph-1 KO mice associated with severe loss and disorganization of motile ependymal cilia in the ventricular lining, a cell type that normally expresses high levels of synphilin-1. Ultrastructural and immunohistochemical analyses revealed disrupted ependymal architecture, mislocalization of acetylated α-tubulin to the cytoplasm, cellular swelling, and enlarged, aberrant mitochondria, whereas cortical neurons appeared largely structurally unaffected. Together, these findings identify synphilin-1 as a key regulator of microtubule organization and cytoskeletal/organelle homeostasis in ependymal cells, required to maintain motile ciliogenesis, cerebrospinal fluid flow, and ventricular integrity. This unexpected role for synphilin-1 in ciliated brain epithelia, along with a reduction in the critical mitochondrial chaperone HSP60, broadens our understanding of synphilin-1 biology and provides a new framework for its potential relevance to PD-associated pathology. Full article

Fruit branch length in cotton is a key trait influencing plant architecture and suitability for mechanisation; elucidating its molecular regulatory mechanisms is crucial for breeding varieties with desirable plant architecture. In this study, an F₂ segregating population was established using the long-fruit-branch upland cotton line L16 and the short-fruit-branch line S14 as parents. By integrating morphological, cytological, and omics approaches, we systematically analysed the underlying mechanisms of variation in fruit branch length. Phenotypic analysis indicated that the inter-node elongation rate of the first fruit branch in L16 was significantly higher than that in S14. Tissue section observations revealed that the length of cortical parenchyma cells in L16 was significantly greater than that in S14, suggesting that the difference in fruit branch length primarily stems from variations in the extent of cortical parenchyma cell elongation. BSA-Seq analysis identified five QTL regions significantly associated with fruit branch length, encompassing 82 coding genes. Further RNA-Seq analysis of the fruit branch initiation stage (T0) and rapid elongation stage (T1) identified 3106 differentially expressed genes common to both stages. GO and KEGG enrichment analyses revealed that these genes were significantly enriched in pathways related to plant hormone signalling, the cytoskeleton, and microtubule organisation. By integrating BSA-Seq and RNA-Seq data, three candidate genes were screened that simultaneously harboured non-synonymous mutations and were significantly highly expressed in the short fruit branch line S14. Combined with bioinformatics analysis, GH_D02G0744 was predicted to be the most likely key candidate gene regulating cotton fruit branch length. This study provides important genetic resources to elucidate the molecular regulatory mechanisms of cotton fruit branch length and lays a theoretical foundation for molecular breeding to improve cotton plant architecture. Full article

In this study, the ultrastructural characteristics of the mature spermatozoon of the cestode Gerbillitaenia psammomi, a parasite of the fat sand rat (Psammomys obesus) in the south of Tunisia, were examined by means of transmission electron microscopy. The spermatozoon is of Levron et al.’s type VI. This type of sperm cell is mainly characterized by the presence of a single axoneme of the 9 + ‘1’ pattern typical of the trepaxonematan Platyhelminthes, crest-like bodies, a periaxonemal sheath, twisted cortical microtubules, and a spiraled nucleus. The spermatozoon of G. psammomi possesses two crest-like bodies of different length. The results obtained in the present study suggest certain similarities with the remaining analyzed catenotaeniids; namely, Catenotaenia pusilla, Skrjabinotaenia (Meggittina) gerbilli, and Spasskijela lobata. The results are compared and discussed according to several characteristics found in the catenotaeniids and other studied cestodes, particularly those of the order Cyclophyllidea. Full article

Different components of the cytoskeleton are very important determinants of brain development. They orchestrate multiple cellular processes involved in all phases of cerebral cortex development. In this review, we summarize current knowledge on the components of the cytoskeleton—microtubules, actin filaments, and intermediate filaments—and their roles in cortical development. We provide a detailed analysis of how cytoskeleton molecules control neuronal progenitor proliferation, neuronal migration, polarization, axon and dendrite specification and outgrowth, and synaptogenesis. We further examine how pathogenic variants in genes encoding cytoskeletal proteins or their regulators disrupt particular steps of neurogenesis and contribute to major neurodevelopmental disorders (NDDs). Focusing on NDDs such as microcephaly, lissencephaly, corpus callosum agenesis, and synaptopathies, we discuss consequences of cytoskeletal dysfunctions causing altered cellular behavior and clinical phenotypes. By linking molecular defects to developmental and phenotypic consequences, this review highlights the cytoskeleton as a central element in neurodevelopmental pathologies and underscores its potential as a target for future therapeutic strategies. Full article

Background: We evaluated the potential neuroprotective effects of naloxone in moderate traumatic brain injury (TBI), focusing on its ability to alleviate neuroinflammation, reduce cognitive impairment, and to influence Janus tyrosine kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling markers. Methods: Male C57BL/6J mice were used to establish an in vivo model of moderate TBI using a stereotaxic impactor. Immediately post-injury, naloxone was administered intraperitoneally (1 mg/kg/day) for 7 days. A total of 72 mice were divided into four groups: Normal, normal with naloxone, TBI, and TBI with naloxone (18 mice in each group). Immunohistochemical analyses and cognitive functions were evaluated across the groups. Results: TBI mice treated with naloxone exhibited significantly reduced brain swelling and cortical tissue loss compared to untreated mice. Naloxone reduced Transforming growth factor beta 2 (TGF-β2) and increased interleukin 11 (IL-11) expression in the brain. Additionally, levels of JAK2, STAT3, and B-cell lymphoma 2 (Bcl-2) were significantly elevated following treatment, while expressions of Tumor protein p53 (p53), Caspase 3, Microtubule-associated proteins 1A/1B light chain 3B (LC3B), and Sequestosome 1 (p62) were reduced. Fluorescence intensities of ionized calcium binding adaptor molecule (Iba-1) and dichloro-dihydro-fluorescein diacetate (DCFH-DA) were enhanced, indicating decreased microglial activation and reactive oxygen species (ROS) production due to naloxone treatment. Cognitive function tests revealed improved performance in TBI mice treated with naloxone, demonstrated by decreased alteration rates in the Y-maze test and improved preference index scores in the novel object recognition (NOR) test. Conclusions: Naloxone shows potential for neuroprotection and enhanced cognitive performances, which may be associated with modulation of JAK2/STAT3 signaling in a mouse model of moderate TBI. Full article

Cortical microtubules comprise heterodimeric units of α- and β-tubulin which have been shown to guide the deposition of cellulose microfibrils in plant cell walls where their arrangement is important in determining cell morphology and cell wall properties. Tubulin genes are highly expressed in woody tissues and a functional study has demonstrated a role for a β-tubulin gene family member in affecting the orientation of cellulose microfibrils in wood fibre cells, an important trait in determining the mechanical properties of wood fibres. To further understand the role of tubulins in plant cell trait determination, this study identified and investigated the expression of the α- and β-tubulin gene families in Eucalyptus and then, using transgenesis techniques, investigated the role of specific eucalypt tubulin isoforms in determining secondary cell wall traits of wood fibres in plant stems. This study found that the α- and β-tubulin gene families in Eucalyptus are relatively small compared to other species and show higher expression in woody stem tissue when compared to leaf. Functional studies revealed that cambial cells transformed with α- and β-tubulin overexpression and knockdown vectors, either on their own or in combination, lead to changes in the angle of microfibrils in the secondary cell wall of wood fibre cells with Class I- and Class I-like gene family members explicitly involved. This study demonstrates the importance of tubulins in determining the mechanical properties of wood fibres through a mechanism involving specific tubulin isoform expression during wood fibre formation. Full article

Malformations of cortical development (MCD) are a group of neurodevelopmental disorders caused by abnormalities in cerebral cortex development, leading to conditions such as intellectual disability and refractory epilepsy. The prenatal phenotypes of MCD are complex and non-specific, complicating accurate diagnosis and prognosis assessment. Genetic testing, particularly chromosomal microarray analysis (CMA) and whole-exome sequencing (WES), has become an important tool for prenatal diagnosis. This review synthesizes current research on prenatal MCD, focusing on the integration of imaging and genetic diagnostic strategies based on the biological foundation of cortical development and the classification system of MCD. Prenatal MCD phenotypes show significant developmental stage clustering, with proliferation-phase abnormalities (62.9%) being the most common and microcephaly as the core phenotype. Genetic studies have revealed a high degree of genetic heterogeneity in MCD, with etiologies encompassing chromosomal abnormalities and a wide range of single-gene mutations. These mutations are clustered by phenotype: microcephaly is associated with neuronal proliferation/DNA repair genes; macrocephaly is driven by genes in the PI3K-AKT-mTOR and RAS-MAPK signaling pathways; and gyral and sulcal abnormalities are closely linked to microtubule-associated genes and migration pathways. De novo mutations account for the majority of pathogenic genetic alterations identified in MCD (50.6%); up to 75.1% of pathogenic mutations cannot be detected by routine prenatal screening. Based on this, the review emphasizes that for fetuses with suspected MCD, NGS, with WES at its core, plays an increasingly important role in achieving early and accurate prenatal diagnosis. Future research should prioritize the advancement of integrated diagnostic methods and large-scale cohort studies to further elucidate genotype–phenotype associations. Full article

Accumulation of the microtubule-associated protein TAU into inclusions is a hallmark of tauopathies including Alzheimer’s disease (AD), potentially driven by impaired protein degradation and dysregulated ubiquitination. To explore the role of deubiquitinating enzymes (DUBs), we performed siRNA knockdown screens targeting 93 murine DUBs in rTg4510 cortical cultures. Knockdown and pharmacological inhibition of the ubiquitin-specific proteases 7 (Usp7) and 10 (Usp10) significantly reduced seeded TAU aggregation without affecting soluble TAU levels. These effects were observed in both cortical and organotypic hippocampal slice cultures from rTg4510 mice, as well as in wildtype neurons seeded with AD-derived pathological TAU. Inhibition of Usp7 and Usp10 was associated with increased polyubiquitination of residual TAU inclusions in rTg4510 cortical cultures. These findings suggest that Usp7 and Usp10 contribute to pathological TAU accumulation by modulating ubiquitin-dependent degradation pathways. Targeting USP7 and USP10 may offer a novel therapeutic strategy for AD and related tauopathies. Full article

Tubulin cytoskeleton rearrangements play an important role in the cell differentiation of symbiotic nodules in legumes. However, the organization of the tubulin cytoskeleton has been investigated only for four legume species forming determinate nodules (with limited nodule meristem activity). In this study, microtubule organization was studied in three species (Vigna radiata, V. unguiculata, and Lotus corniculatus) with determinate nodules using confocal laser scanning microscopy and quantitative analyses. Histological organization in young nodules of V. radiata and V. unguiculata resembled the recently reported zonation in young nodules of Glycine max. In addition, bacteroids in nodules of these species were significantly enlarged compared to free-living bacteria. Organization of endoplasmic and cortical microtubules in young infected cells and uninfected cells and that of cortical microtubules in nitrogen-fixing cells demonstrated general patterns for determinate nodules, whereas endoplasmic microtubules in nitrogen-fixing cells showed species-specific patterns. Thus, the presence of both general and species-specific patterns of tubulin cytoskeleton organization was confirmed in determinate nodules. Full article

The insulin-regulated aminopeptidase (IRAP; oxytocinase) is part of the M1 aminopeptidase family and is highly expressed in many tissues, including the neocortex and hippocampus of the brain. IRAP is involved in various physiological functions and has been identified as a receptor for the endogenous hexapeptide Angiotensin IV (Ang IV). The binding of Ang IV inhibits the enzymatic activity of IRAP and has been proven to enhance learning and memory in animal models. The macrocyclic compound 9 (C9) is a potent synthetic IRAP inhibitor developed from the previously reported inhibitor HA08. In this study, we have examined compound C9 and its effects on cognitive markers drebrin, microtubule-associated protein 2 (MAP2), and glial fibrillary acidic protein (GFAP) in primary hippocampal and cortical cultures. Cells from Sprague Dawley rats were cultured for 14 days before treatment with C9 for 4 consecutive days. The cells were analysed for protein expression of drebrin, MAP2, GFAP, glucose transporter type 4 (GLUT4), vesicular glutamate transporter 1 (vGluT1), and synapsin I using immunocytochemistry. The gene expression of related proteins was determined using qPCR, and viability assays were performed to evaluate toxicity. The results showed that protein expression of drebrin and MAP2 was increased, and the corresponding mRNA levels were decreased after treatment with C9 in the hippocampal cultures. The ratio of MAP2-positive neurons and GFAP-positive astrocytes was altered and there were no toxic effects observed. In conclusion, the IRAP inhibitor compound C9 enhances the expression of the pro-cognitive markers drebrin and MAP2, which further confirms IRAP as a relevant pharmaceutical target and C9 as a promising candidate for further investigation. Full article

Microtubule-associated proteins (MAPs) play a pivotal role in the assembly and stabilization of microtubules, which are essential for plant cell growth, development, and morphogenesis. A class of plant-specific MAPs, MAP65, plays largely unexplored roles in moso bamboo (Phyllostachys edulis). This study identified 19 PeMAP65 genes in moso bamboo, systematically examining their phylogenetic relationships, conserved motifs, gene structures, collinearity, and cis-acting elements. Analysis of gene expression indicated that PeMAP65s exhibit tissue-specific expression patterns. Functional differentiation was investigated among the members of different PeMAP65 subfamilies according to their expression patterns in different development stages of bamboo shoots. The expression of PeMAP65-18 was positively correlated with the expression of genes involved in secondary cell wall (SCW) biosynthesis. Y1H and Dual-LUC assays demonstrated that the transcription of PeMAP65-18 was upregulated by PeMYB46, a key transcription factor of SCW biosynthesis. The result of subcellular localization showed that PeMAP65-18 was located in cortical microtubules. We speculate that PeMAP65-18 may play a crucial role in the SCW deposition of moso bamboo. This comprehensive analysis of the MAP65 family offers novel insights into the roles of PeMAP65s in moso bamboo, particularly in relation to the formation of SCWs. Full article

The study of sperm characteristics has proven useful for elucidating interrelationships in several groups of Platyhelminthes, such as digeneans. Thus, in the present work, the ultrastructural organization of the mature spermatozoon of the digenean Artyfechinostomum malayanum (Echinostomatidae), a parasite of Rattus norvegicus (Rodentia: Muridae) from Dong Thap Province, Vietnam, was investigated for the first time using transmission electron microscopy. The male gamete of A. malayanum exhibits two axonemes of different lengths, showing the 9 + ‘1’ pattern of the Trepaxonemata, a nucleus, two mitochondria, two lateral expansions, two bundles of parallel cortical microtubules, external ornamentation, spine-like bodies, and granules of glycogen. Thus, the mature spermatozoon follows a Type V sperm model proposed for digeneans. We also highlight some noteworthy characteristics in Echinostomatidae with possible phylogenetic implications, such as two lateral expansions in the anterior region of the spermatozoon and two mitochondria. Full article

An Arabidopsis sterol mutant, smt2 smt3, defective in sterolmethyltransferase2 (SMT2), exhibits severe growth abnormalities. The loss of C-24 ethyl sterols, maintaining the biosynthesis of C-24 methyl sterols and brassinosteroids, suggests specific roles of C-24 ethyl sterols. We characterized the subcellular localizations of fluorescent protein-fused sterol biosynthetic enzymes, such as SMT2-GFP, and found these enzymes in the endoplasmic reticulum during interphase and identified their movement to the division plane during cytokinesis. The mobilization of endoplasmic reticulum-localized SMT2-GFP was independent of the polarized transport of cytokinetic vesicles to the division plane. In smt2 smt3, SMT2-GFP moved to the abnormal division plane, and unclear cell plate ends were surrounded by hazy structures from SMT2-GFP fluorescent signals and unincorporated cellulose debris. Unusual cortical microtubule organization and impaired cytoskeletal function accompanied the failure to determine the cortical division site and division plane formation. These results indicated that both endoplasmic reticulum membrane remodeling and cytokinetic vesicle transport during cytokinesis were impaired, resulting in the defects of cell wall generation. The cell wall integrity was compromised in the daughter cells, preventing the correct determination of the subsequent cell division site. We discuss the possible roles of C-24 ethyl sterols in the interaction between the cytoskeletal network and the plasma membrane. Full article