Photoreceptor calyceal processes accompany the developing outer segment, adopting a stable length despite a dynamic core

Journal of Cell Science, Год журнала: 2024, Номер 137(7)

Опубликована: Март 13, 2024

ABSTRACT Vertebrate photoreceptors detect light through a large cilium-based outer segment, which is filled with photopigment-laden membranous discs. Surrounding the base of segment are microvilli-like calyceal processes (CPs). Although CP disruption has been associated altered morphology and photoreceptor degeneration, role CPs remains elusive. Here, we used zebrafish as model to characterize CPs. We quantified parameters report strong disparity in coverage between subtypes. length stable across dark conditions, yet heat-shock inducible expression tagged actin revealed rapid turnover core. Detailed imaging embryonic retina uncovered substantial remodeling developing apical surface, including transition from dynamic tangential vertically oriented immediately prior formation. Remarkably, also found direct connection extensions Müller glia retinal pigment epithelium, arranged bundles around ultraviolet sensitive cones. In summary, our data structure, development surrounding environment microvilli retina.

Язык: Английский

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The morphological and functional diversity of apical microvilli

Journal of Anatomy, Год журнала: 2022, Номер 242(3), С. 327 - 353

Опубликована: Окт. 25, 2022

Abstract Sensory neurons use specialized apical processes to perceive external stimuli and monitor internal body conditions. The apparatus can include cilia, microvilli, or both, is adapted for the functions of particular cell type. Photoreceptors detect light through a large, modified cilium (outer segment), that supported by surrounding ring microvilli‐like calyceal (CPs). Although first reported 150 years ago, CPs remain poorly understood. As basis future study, we therefore conducted review existing literature about sensory which act either as primary detector support cilia‐based detector. While all microvilli are finger‐like cellular protrusions with an actin core, vary across types in size, number, arrangement, dynamics, function. We summarize current state knowledge characteristics found on inner ear hair cells (stereocilia) cerebral spinal fluid‐contacting neurons, comparisons brush border intestinal renal epithelia. structure, stability, dynamics core regulated complement actin‐binding proteins, includes both common components unique features when compared types. Further, often lateral links, glycocalyx, defined extracellular matrix, each function environment cell. Our comparison microvillar will inform further research into how photoreceptor function, also provide general investigations structure neurons.

Язык: Английский

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Origin and evolution of microvilli

Biology of the Cell, Год журнала: 2024, Номер 116(11)

Опубликована: Сен. 5, 2024

Abstract Background Information Microvilli are finger‐like, straight, and stable cellular protrusions that filled with F‐actin present a stereotypical length. They in broad range of cell types across the animal tree life mediate several fundamental functions, including nutrient absorption, photosensation, mechanosensation. Therefore, understanding origin evolution microvilli is key to reconstructing form function. Here, we review current state knowledge on perform bioinformatic survey conservation genes encoding microvillar proteins animals their unicellular relatives. Results We first detailed description mammalian based two well‐studied examples, brush border enterocytes stereocilia hair cells. also broader diversity discuss similarities differences between filopodia. Based our coupled carefully reconstructed molecular phylogenies, reconstitute order evolutionary appearance proteins. document stepwise assembly “molecular toolkit” notable bursts innovation at nodes: last common filozoan ancestor (correlated distinct from filopodia) choanozoan emergence inter‐microvillar adhesions). Conclusion Significance conclude scenario for filopodia‐like ancestral structures precursors animals.

Язык: Английский

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Microvilli regulate the release modes of alpha-tectorin to organize the domain-specific matrix architecture of the tectorial membrane.

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Янв. 5, 2024

Abstract The tectorial membrane (TM) is an apical extracellular matrix (ECM) in the cochlea essential for auditory transduction. TM exhibits highly ordered domain-specific architecture. Alpha-tectorin/TECTA a glycosylphosphatidylinositol (GPI)-anchored ECM protein organization. Here, we identified that TECTA released by distinct modes: proteolytic shedding TMPRSS2 and GPI-anchor-dependent release from microvillus tip. In medial/limbal domain, proteolytically shed forms dense fibers. lateral/body domain produced supporting cells displaying microvilli, restricts to tip compartmentalizes collagen-binding site. tip-localized TECTA, turn, manner form collagen-crosslinking fibers, required maintaining spacing parallel organization of collagen fibrils. Overall, showed modes determine pattern, coordinates along its organize higher-order Figure Graphical

Язык: Английский

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Microvilli control the morphogenesis of the tectorial membrane extracellular matrix

Developmental Cell, Год журнала: 2024, Номер unknown

Опубликована: Дек. 1, 2024

Язык: Английский

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Effects of honey saccharide supplementation on growth performance, amylase enzyme activity, gut microvilli, and microbiome in Cyprinus carpio

Veterinary World, Год журнала: 2025, Номер unknown, С. 228 - 237

Опубликована: Янв. 1, 2025

Prebiotics, such as saccharides in honey, play a crucial role improving gut microbiota, digestion, and immune function. This study evaluates the effects of Kapok flower honey on growth performance, digestive enzyme activity, intestinal morphology, microbiota common carp (Cyprinus carpio). A completely randomized design was implemented with four supplementation levels (0% control, 0.5%, 0.75%, 1%) applied to juvenile C. carpio diets over 30 days. Growth feed utilization, microvilli structure, amylase activity were analyzed using advanced techniques, including high performance liquid chromatography, scanning electron microscopy, biochemical assays. contains fructooligosaccharides (FOS, 14.76%) inulin (6.6%). Supplementation at 1% significantly improved weight gain, conversion ratio, specific rate. Amylase increased supplementation, peaking 24.13 ± 3.11 U g-1 protein for group. Gut morphology analysis revealed longer, denser higher perimeter ratios honey-treated groups than controls. Microbiota showed beneficial Bacillus spp. exclusively honey-supplemented groups. Honey saccharides, particularly FOS inulin, enhance health carp. is optimal, efficiency fostering microbiota. These findings highlight cost-effective, natural prebiotic aquaculture.

Язык: Английский

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The USH3A causative gene clarin1 functions in Müller glia to maintain retinal photoreceptors

PLoS Genetics, Год журнала: 2025, Номер 21(3), С. e1011205 - e1011205

Опубликована: Март 11, 2025

Mutations in CLRN1 cause Usher syndrome type IIIA (USH3A), an autosomal recessive disorder characterized by hearing and vision loss, often accompanied vestibular dysfunction. The identity of the cell types responsible for pathology mechanisms leading to loss USH3A remains elusive. To address this, we employed CRISPR/Cas9 technology delete a large region coding untranslated (UTR) zebrafish clrn1 . retinas mutant larvae exhibited sensitivity stress, along with age-dependent function degeneration photoreceptor layer. Investigation revealed disorganization outer retina mutants, including actin-based structures Müller glia cells. assess cell-specific contributions pathology, specifically re-expressed either or re-expression prevented elevated death observed larval exposed high-intensity light. Notably, degree phenotypic rescue correlated level Clrn1 re-expression. Surprisingly, high levels expression enhanced both wild-type animals. However, rod- cone-specific did not reduce extent death. Taken together, our findings underscore three crucial insights. First, exhibit key pathological features USH3A; second, within plays pivotal role maintenance, its requiring controlled regulation; third, reliance photoreceptors on suggests structural support mechanism, possibly through direct interactions between mediated part protein.

Язык: Английский

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Tekt3 Safeguards Proper Functions and Morphology of Neuromast Hair Bundles

International Journal of Molecular Sciences, Год журнала: 2025, Номер 26(7), С. 3115 - 3115

Опубликована: Март 28, 2025

The inner ear and/or lateral line are responsible for hearing and balance of vertebrate. otic sensory hair cells (HCs) employ cilium organelles, namely stereocilia kinocilia, to mediate mechanical stimuli electrical signal transition. Tektins (Tekts) known as the microtubule stabilizer inner-space filler, four Tekt(1-4)-encoding genes identified in zebrafish HCs, but subcellular location Tekts HCs remains unknown. In present study, we first found that tekt3 is expressed neuromast. Antibody staining revealed Tekt3 neuromast utricular HCs. It absent saccule, authentic end-organ crista semi-circular canals. Furthermore, were enriched at apical side mainly cytosol. Similar distribution was also evident outer mature mouse cochlea, which not directly linked sense. However, only exerted morphological defect kinocilia mutant. disrupted or distorted HC mutant ultimately resulted slower vital dye intake, delayed regeneration after neomycin treatment, reduced startle response vibration stimulation. All functional defects largely rescued by wild-type mRNA. Our study thus suggests maintains integrity function against surrounding persistent low-frequency noises, perhaps via intracellular Tekt3. Nevertheless, TEKT3/Tekt3 could be used clarify sub-types both mice, highlight non-hearing

Язык: Английский

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Immunolabel imaging of plasma membrane Ca++ pumps (PMCA-pan or PMCA2) implicates the apical cilium on receptor cells as the transduction site for electrosense in two Acipenseriformes fishes

Tissue and Cell, Год журнала: 2025, Номер unknown, С. 102928 - 102928

Опубликована: Май 1, 2025

Язык: Английский

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Generation and maintenance of apical rib-like actin fibers in epithelial support cells of the Drosophila eye

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2025, Номер unknown

Опубликована: Май 14, 2025

Heterogeneity and complexity of cytoskeletal structures, how these are regulated, is poorly understood. Here we use cells the Drosophila pupal eye as models to explore diversity in actin cytoskeleton. We found that different F-actin structures emerge primary (1°), secondary (2°), tertiary (3°) pigment they mature. 1° became characterized by dense accumulations apical termed Apical Ribs Actin Fibers (ARAFs). The formins Diaphanous Dishevelled Associated Activator Morphogenesis essential for generation ARAFs, which connected into a network α-Actinin, villin Quail, Spectrins, linked membrane Quail Spectrins. ARAFs contractile, stress-fiber-like, connect adherens junctions. Impairing indicated this maintains cortical tension crucial 1°s achieve their characteristic shapes. Our evaluation three-dimensional shape reveals rounding elevation membrane. Hence, toolkit conserved regulatory proteins builds stress fibers governs morphology cell. This study describes novel shapes region uncovers set build maintain network.

Язык: Английский

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