key: cord-0324121-tttpk9at authors: Cheung, King Yee; Jesuthasan, Suresh J.; Baxendale, Sarah; van Hateren, Nicholas J.; Marzo, Mar; Hill, Christopher J.; Whitfield, Tanya T. title: Olfactory rod cells: a rare cell type in the larval zebrafish olfactory epithelium with an actin-rich apical projection date: 2020-11-05 journal: bioRxiv DOI: 10.1101/2020.11.04.367979 sha: b0df85c84ab5a2be1292a73ac0a6aa2ba99ae928 doc_id: 324121 cord_uid: tttpk9at We report the presence of a rare cell type, the olfactory rod cell, in the developing zebrafish olfactory epithelium. These cells each bear a single actin-rich rod-like apical projection extending about 10 μm from the epithelial surface. Live imaging with a ubiquitous Lifeact-RFP label indicates that the rods can oscillate. Olfactory rods arise within a few hours of the olfactory pit opening, increase in numbers and size during larval stages, and can develop in the absence of olfactory cilia. Olfactory rod cells differ in morphology from the known classes of olfactory sensory neuron, but express reporters driven by neuronal promoters. The cells also differ from secondary sensory cells such as hair cells of the inner ear or lateral line, or sensory cells in the taste bud, as they are not associated with established synaptic terminals. A sub-population of olfactory rod cells expresses a Lifeact-mRFPruby transgene driven by the sox10 promoter. Mosaic expression of this transgene reveals that olfactory rod cells have rounded cell bodies located apically in the olfactory epithelium. In addition to common cell types, tissues may also contain rare or sparsely- 132 The -4725sox10:Lifeact-mRFPruby construct was generated using the Gateway Tol2 133 kit (Kawakami, 2007; Kwan et al., 2007) . The p5E -4725sox10 promoter (Dutton et Zebrafish embryos and larvae were fixed in 4% paraformaldehyde (PFA) in 145 phosphate-buffered saline (PBS) for two hours at room temperature or overnight at 146 4°C. Zebrafish were washed three or more times with PBS, and permeabilised by 147 incubation in PBS-Triton X-100 (0.2% Triton for 32-48 hpf embryos, 1% Triton for 148 later stages) for several hours at 4°C until staining. which was then used for performing statistical analyses and making graphs. 279 As described above, olfactory rods differ from olfactory cilia in terms of size, shape, 280 cytoskeletal composition, and distribution in the OE. We therefore hypothesised that 281 olfactory rod cell projections would not be affected by mutations that disrupt the 282 formation of cilia. To test this, we examined fish mutant for ift88, which codes for a 326 Given the superficial similarity in appearance of the olfactory rod to hair-cell 327 stereocilia in phalloidin stains, and a report of a rare cell type bearing stereocilia-like (Schulte, 1972) . Olfactory rods in the other four species measured 1 µm 454 in diameter and 10 µm in length. Rods were either found to exist solitarily or in a 455 group; interestingly, it was noted that olfactory cilia were sparse in areas where rods 456 occurred in a group (Yamamoto & Ueda, 1978) . images showing no effect of 500 µM neomycin treatment for 60 minutes on olfactory rods, using 751 Alexa-phalloidin as a marker; anterior to the top, lateral to the right. Arrowheads mark olfactory rods. Neue Morphologische Grundlagen Zur Physiologie Des 822 The Molecular Logic Of Smell The Fine Structure of the Olfactory Surface of Teleostean 825 Is Rhabdospora Thelohani (Laguesse) a Sporozoan Parasite 827 or a Tissue Cell of Lower Vertebrates? Assembly of Hair Bundles, an Amazing Problem for Cell 829 Forces Driving Epithelial Spreading in 832 Assaying Sensory Ciliopathies Using Calcium Biosensor Expression in 835 Cell Markers in the Olfactory Organ of Poecilia Reticulata: Analysis and 838 Comparison with the Fish Model Danio Rerio. Brain Structure and Function Differences in Chemosensory Response 842 between Eyed and Eyeless Astyanax Mexicanus of the Rio Subterráneo Cave. Specific for Secretory Vesicles of Neural and Endocrine Cells The Olfactory System of Zebrafish as 857 a Model for the Study of Neurotoxicity and Injury: Implications for Neuroplasticity 858 and Disease Bacteria Evoke Alarm Behaviour in 861 Pathogens Penetrating the 864 Central Nervous System: Infection Pathways and the Cellular and Molecular 865 Mechanisms of Invasion Ultrastructure of Cell Types of the 867 Olfactory Epithelium in a Catfish, Heteropneustes Fossilis (Bloch) Signalling Selectively Modulates Maintenance but Not Repair Neurogenesis in 872 the Zebrafish Olfactory Epithelium Tropomyosin and Alpha-Actinin in Teleost Rodlet Cells Measuring the Primary Cilium Length: Improved Method for Unbiased 889 Brain-Wide Mapping of 892 An Evolutionarily Conserved Intronic Region 895 Controls the Spatiotemporal Expression of the Transcription Factor Sox10 Sox10 and Specifies Non-Ectomesenchymal Neural Crest Fates. Development Transcriptome Atlas for Zebrafish Development Solitary Chemoreceptor Cells in the Nasal Cavity Serve as 906 Sentinels of Respiration A Novel Perivascular Cell Population in the Zebrafish Sensors The Cellular Basis of Loss of Smell Taste Bud Development in the 921 Development of the Olfactory Organ in the 923 The Peripheral Olfactory Organ of the Zebrafish Danio Rerio: An Ultrastructural Study Diversity in the Olfactory Epithelium of Bony 928 Fishes: Development, Lamellar Arrangement Neomycin-Induced Hair Cell Death and Rapid 932 Regeneration in the Lateral Line of Zebrafish (Danio Rerio) Actin Alone in Lamellipodia Fine Structural Characterization of the Olfactory Epithelium and 937 Its Response to Divalent Cations Cd2+ in the Fish Alburnus Alburnus A Scanning and Transmission Electron Microscopic Study Single-Cell 942 Larval Zebrafish Use Olfactory Detection of Sodium and Chloride to Avoid Salt-Water Localisation of Actin, Villin, Fimbrin Ankyrin in Rat Taste Receptor Cells Tuft Cells, Taste-Chemosensory Cells, Orchestrate Parasite Type 952 2 Immunity in the Gut Fine Structure of the Olfactory Epithelium in the 954 Goldfish Keratins and Plakin Family Cytolinker Proteins Control the Length of Epithelial 957 Mechanosensory-Based Phase Coding of 959 Odor Identity in the Olfactory Bulb Artificial Chromosome Transgenesis 961 Reveals Long-Distance Negative Regulation of Rag1 in Zebrafish Tol2: A Versatile Gene Transfer Vector in Vertebrates ZTrap: Zebrafish Gene Trap and Enhancer Trap Database Neural Circuits Mediating Olfactory-Driven Behavior in Fish Stages of Embryonic Development of the Zebrafish Ontogeny of the Solitary Cavefish and the Basis for Eye Loss Multisite Gateway-Based Construction Kit for Tol2 Transposon Transgenesis 986 Intracellular Uptake of Macromolecules by Brain 989 Sensational Placodes: Neurogenesis in the Otic and Olfactory Systems Cells Resembling Hair Cells in Developing 995 Rat Olfactory and Nasal Respiratory Epithelia Genetic Lineage Labeling in Zebrafish Uncovers 998 Novel Neural Crest Contributions to the Head, Including Gill Pillar Cells A Revised Airway Epithelial Hierarchy Includes CFTR-1001 Expressing Ionocytes Ultrastructural 1003 Neurobiology of the Olfactory Mucosa of the Brown Trout Distribution and Morphology of the Rodlet 1006 Cell in Fish Site-Directed Zebrafish Transgenesis into Single Landing Sites with the 1009 Three Distinct Morphological Classes of 1011 Receptors in Fish Olfactory Organs Zebrafish: A Practical Approach An Update on Anatomy and Function of 1016 the Teleost Olfactory System Immunohistochemical Characterization of the Crypt 1019 Neurons in the Olfactory Epithelium of Adult Zebrafish Microridges Are Apical Epithelial Projections Formed of F-Actin 1023 Synaptic Vesicle Protein 1025 2, a New Neuroendocrine Cell Marker Simultaneous Single-Cell Profiling of 1029 Lineages and Cell Types in the Vertebrate Brain Cytonemes : Cellular Processes 1032 That Project to the Principal Signaling Center in Drosophila Imaginal Discs. Cell, 1033 97 The Mysterious Pulmonary Brush Cell: A Cell in Search of a Function Motile-Cilia-Mediated Flow Improves Sensitivity and Temporal 1040 Resolution of Olfactory Computations Surface 1042 Specializations of the Olfactory Epithelium of Rainbow Trout, Salmo Gairdneri Lifeact: A Versatile Marker to Visualise F-Actin A Novel 1049 Transgenic Line Using the Cre-Lox System to Allow Permanent Lineage-1050 Labeling of the Zebrafish Neural Crest Spatial 1052 Reconstruction of Single-Cell Gene Expression Data Mutually Exclusive Glomerular Innervation by Two Distinct Types of Olfactory Sensory Neurons Sox10-Dependent Neural Crest 1058 Origin of Olfactory Microvillous Neurons in Zebrafish Source Platform for Biological-Image Analysis A 1064 High-Level 3D Visualization API for Java and ImageJ Regulation of Immune 1067 Responses by Tuft Cells Untersuchungen an Der Regio Olfactoria Des Aals Zeitschrift für Zellforschung und Mikroskopische Anatomie Espins Are Multifunctional Actin Cytoskeletal 1073 Regulatory Proteins in the Microvilli of Chemosensory and Mechanosensory 1074 Ultrastructural Characterization of 1076 the Olfactory Organ in Glass Eels Neural Crest Lineage Analysis: From Past to 1083 Actin Microfilament Dynamics in Locomoting 1085 Cells The Organization of Actin 1087 Filaments in the Stereocilia of Cochlear Hair Cells Intraflagellar Transport Genes Are Essential for 1090 Differentiation and Survival of Vertebrate Sensory Neurons An Adenosine Receptor for Olfaction in Fish Surface Architecture of the Olfactory 1097 Epithelium of Two Chinese Cave Loaches Anatomical Studies 1100 of the Olfactory Epithelium of Two Cave Fishes Sinocyclocheilus Jii and S Cypriniformes: Cyprinidae) from China A Transgenic System for Rapid Magnetic 1104 Enrichment of Rare Embryonic Cells The Loss of Scents: Do Defects in Olfactory Sensory Neuron 1106 Development Underlie Human Disease? Birth Defects Research Part C -1107 Embryo Today: Reviews A GFP-Based Genetic Screen 1109 Reveals Mutations That Disrupt the Architecture of the Zebrafish Retinotectal 1110 Projection Comparative Morphology of Fish Olfactory 1112 Confocal Imaging of Merkel-like Basal Cells in the Taste Buds of Zebrafish Microscopic and Submicroscopic Gradient Variation of Olfactory 1118 Systems among Six Sinocyclocheilus Species Living in Different Environments 618 We thank Karen Carmargo Sosa and Robert Kelsh for providing fixed sox10 -/larvae. 619 We thank Henry Roehl for making the p5E -4725 sox10 promoter (originally from the 620 Kelsh lab), Lifeact-mRFPruby construct (originally from the Wedlich-Söldner and Sixt