Meckelin guides orientation of basal bodies along the striated rootlet

Attached to the basal bodies of Naegleria gruberi flagellates is a striated rootlet or rhizoplast. The rootlet-basal body complex has been isolated by Triton X-100 lysis of deflagellated cells and differential centrifugation through a 25% glycerol medium. Rootlets isolated from mature flagellates are approximately 13 micrometers long but vary from 8 to 15 micrometers in length: they taper at both ends from a maximum width of approximately 0.25 micrometers in the vicinity of the basal bodies. They are highly stable during isolation but can be solubilized by urea, high salt, low pH, or detergent (Sarkosyl). Partial dissociation of rootlets with 1 M urea reveals that they are composed of filaments, approximately 5 nm diameter, associated in a linear fashion to yield the characteristic 21-nm cross-banded appearance. Differential solubilization of rootlets and their associated contaminants allowed identification of a major rootlet protein, comprising at least 50% of any purified rootlet preparation, with an apparent subunit molecular weight of 170,000. The localization of rootlets in situ by indirect immunofluorescence using a specific antibody directed against the purified rootlet protein demonstrated unequivocally that this 170,000-dalton protein is an organelle component.

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SF-Assemblin genes in Paramecium: phylogeny and phenotypes of RNAi silencing on the ciliary-striated rootlets and surface organization

Cilia ◽

10.1186/s13630-019-0062-y ◽

2019 ◽

Vol 8 (1) ◽

Cited By ~ 1

Author(s):

Ashikun Nabi ◽

Junji Yano ◽

Megan S. Valentine ◽

Tyler Picariello ◽

Judith L. Van Houten

Keyword(s):

Electron Microscopy ◽

Mass Spectrometry ◽

Rna Interference ◽

Cell Membrane ◽

Cell Surface ◽

Potential Role ◽

Basal Bodies ◽

Rnai Silencing ◽

Striated Rootlet ◽

Metachronal Waves

Abstract Background Cilia emanate from basal bodies just underneath the cell membrane. Basal bodies must withstand torque from the ciliary beat and be appropriately spaced for cilia to beat in metachronal waves. Basal body rootlets provide stability for motile cilia. Paramecium has three. Our focus is on the largest one, the striated rootlet (SR). Paramecium basal bodies align in straight rows. Previously we found a potential role for the SR in this alignment. Here we present a phylogeny of the Paramecium homologs of the SF-Assemblin gene of the SR of Chlamydomonas, and the organization of these genes. We describe the phenotypes from RNA interference (RNAi) silencing of genes and gene groups. Methods Phenotypes of the RNAi depletions were characterized by immunofluorescence (IF), electron microscopy, and mass spectrometry. Results We found 30 genes for Paramecium SF-Assemblin homologs (SFA) organized into 13 Paralog Groups (further categorized in five Structural Groups). Representatives of Paralog Groups were found in the SRs. Silencing the transcripts of any of the Structural Groups correlates with misaligned rows of basal bodies, SRs, and cortical units. The silencing of Structural Groups was key and gave us the ability to systematically disrupt SR structures and cell surface organization. Conclusions Silencing of SFA genes and Paralog Groups shows no effects on the SR or the cell surface organization. Silencing of the larger Structural Groups has an enormous impact on rows of basal bodies, SRs and cortical units, and SR striations, and length. Misaligned basal bodies have cilia causing the cells to swim in abnormal paths.

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Ultrastructure of the basal body apparatus in epidermal cells of a sponge larva (Aplysilla SP: Demospongiae)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012504x ◽

1992 ◽

Vol 50 (1) ◽

pp. 928-929

Author(s):

R.L. Pinto ◽

R.M. Woollacott

Keyword(s):

Sodium Bicarbonate ◽

Epoxy Resin ◽

Basal Body ◽

Phosphate Buffer ◽

Similar Data ◽

Basal Apparatus ◽

Striated Rootlet ◽

The Common ◽

Basal Foot ◽

Sexually Mature

The basal body and its associated rootlet are the organelles responsible for anchoring the flagellum or cilium in the cytoplasm. Structurally, the common denominators of the basal apparatus are the basal body, a basal foot from which microtubules or microfilaments emanate, and a striated rootlet. A study of the basal apparatus from cells of the epidermis of a sponge larva was initiated to provide a comparison with similar data on adult sponges.Sexually mature colonies of Aplysillasp were collected from Keehi Lagoon Marina, Honolulu, Hawaii. Larvae were fixed in 2.5% glutaraldehyde and 0.14 M NaCl in 0.2 M Millonig’s phosphate buffer (pH 7.4). Specimens were postfixed in 1% OsO4 in 1.25% sodium bicarbonate (pH 7.2) and embedded in epoxy resin. The larva ofAplysilla sp was previously described (as Dendrilla cactus) based on live observations and SEM by Woollacott and Hadfield.

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Ciliary coordination in newt lung cells requires microtubule-based linkages between basal bodies: A correlative light and EM study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123258 ◽

1992 ◽

Vol 50 (1) ◽

pp. 570-571

Author(s):

Robert Hard ◽

Gerald Rupp ◽

Matthew L. Withiam-Leitch ◽

Lisa Cardamone

Keyword(s):

Basal Body ◽

Untreated Control ◽

Beat Frequency ◽

Primary Cultures ◽

Living Cells ◽

Power Stroke ◽

Ultrastructural Changes ◽

Lung Cells ◽

Basal Bodies ◽

Ciliated Cells

In a coordinated field of beating cilia, the direction of the power stroke is correlated with the orientation of basal body appendages, called basal feet. In newt lung ciliated cells, adjacent basal feet are interconnected by cold-stable microtubules (basal MTs). In the present study, we investigate the hypothesis that these basal MTs stabilize ciliary distribution and alignment. To accomplish this, newt lung primary cultures were treated with the microtubule disrupting agent, Colcemid. In newt lung cultures, cilia normally disperse in a characteristic fashion as the mucociliary epithelium migrates from the tissue explant. Four arbitrary, but progressive stages of dispersion were defined and used to monitor this redistribution process. Ciliaiy beat frequency, coordination, and dispersion were assessed for 91 hrs in untreated (control) and treated cultures. When compared to controls, cilia dispersed more rapidly and ciliary coordination decreased markedly in cultures treated with Colcemid (2 mM). Correlative LM/EM was used to assess whether these effects of Colcemid were coupled to ultrastructural changes. Living cells were defined as having coordinated or uncoordinated cilia and then were processed for transmission EM.

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Functional Redundancy of the B9 Proteins and Nephrocystins in Caenorhabditis elegans Ciliogenesis

Molecular Biology of the Cell ◽

10.1091/mbc.e07-10-1070 ◽

2008 ◽

Vol 19 (5) ◽

pp. 2154-2168 ◽

Cited By ~ 74

Author(s):

Corey L. Williams ◽

Marlene E. Winkelbauer ◽

Jenny C. Schafer ◽

Edward J. Michaud ◽

Bradley K. Yoder

Keyword(s):

Caenorhabditis Elegans ◽

Joubert Syndrome ◽

Cystic Kidney ◽

Basal Bodies ◽

The Novel ◽

C Elegans ◽

Human Genes ◽

Cilia Formation ◽

Strong Candidate ◽

Candidate Loci

Meckel-Gruber syndrome (MKS), nephronophthisis (NPHP), and Joubert syndrome (JBTS) are a group of heterogeneous cystic kidney disorders with partially overlapping loci. Many of the proteins associated with these diseases interact and localize to cilia and/or basal bodies. One of these proteins is MKS1, which is disrupted in some MKS patients and contains a B9 motif of unknown function that is found in two other mammalian proteins, B9D2 and B9D1. Caenorhabditis elegans also has three B9 proteins: XBX-7 (MKS1), TZA-1 (B9D2), and TZA-2 (B9D1). Herein, we report that the C. elegans B9 proteins form a complex that localizes to the base of cilia. Mutations in the B9 genes do not overtly affect cilia formation unless they are in combination with a mutation in nph-1 or nph-4, the homologues of human genes (NPHP1 and NPHP4, respectively) that are mutated in some NPHP patients. Our data indicate that the B9 proteins function redundantly with the nephrocystins to regulate the formation and/or maintenance of cilia and dendrites in the amphid and phasmid ciliated sensory neurons. Together, these data suggest that the human homologues of the novel B9 genes B9D2 and B9D1 will be strong candidate loci for pathologies in human MKS, NPHP, and JBTS.

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An ethanolic phosphotungstic acid (EPTA) analysis of photoreceptor and synaptic ultrastructure in the guinea pig retina.

Journal of Histochemistry & Cytochemistry ◽

10.1177/28.2.6153396 ◽

1980 ◽

Vol 28 (2) ◽

pp. 142-148 ◽

Cited By ~ 1

Author(s):

K R Fry ◽

A W Spira

Keyword(s):

Guinea Pig ◽

Phosphotungstic Acid ◽

Plexiform Layer ◽

Synaptic Cleft ◽

Basal Bodies ◽

Inner Plexiform Layer ◽

Synaptic Terminal ◽

Presynaptic Membrane ◽

Synaptic Ultrastructure ◽

Plexiform Layers

Ethanolic phosphotungstic acid (EPTA) has been used to elucidate the structure of certain organelles contained within retinal cells not clearly discernible using conventional preparations. Both synaptic and nonsynaptic components of the guinea pig neural retina have been analyzed. Within the photoreceptor (PR) cell EPTA-stained components include the connecting cilia, their basal bodies, and the root filament system. Cross-striated fibrillar organelles, similar in appearance to the root filaments, are also observed in the nuclear region, the synaptic terminal and other parts of the PR cell. The possible structural continuity and significance of these structures are discussed. Within retinal synapses of both the inner and outer plexiform layers, ribbons and associated paramembranous specializations are stained. The photoreceptor ribbons have a trialaminar structure with filamentous, tufted borders. Synaptic cleft material and postsynaptic densities are also stained. Bipolar cell synapses in the inner plexiform layer contain stained short ribbons as well as closely associated peg-like densities extending towards the presynaptic membrane.

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The centrin-based cytoskeleton of Chlamydomonas reinhardtii: distribution in interphase and mitotic cells.

The Journal of Cell Biology ◽

10.1083/jcb.107.2.635 ◽

1988 ◽

Vol 107 (2) ◽

pp. 635-641 ◽

Cited By ~ 151

Author(s):

J L Salisbury ◽

A T Baron ◽

M A Sanders

Keyword(s):

Nuclear Envelope ◽

Polyclonal Antibodies ◽

Flagellar Apparatus ◽

Immunogold Labeling ◽

Basal Bodies ◽

Flagellar Roots ◽

Cell Biol ◽

Immunofluorescence Studies ◽

Descending Fibers

Monoclonal and polyclonal antibodies raised against algal centrin, a protein of algal striated flagellar roots, were used to characterize the occurrence and distribution of this protein in interphase and mitotic Chlamydomonas cells. Chlamydomonas centrin, as identified by Western immunoblot procedures, is a low molecular (20,000-Mr) acidic protein. Immunofluorescence and immunogold labeling demonstrates that centrin is a component of the distal fiber. In addition, centrin-based flagellar roots link the flagellar apparatus to the nucleus. Two major descending fibers extend from the basal bodies toward the nucleus; each descending fiber branches several times giving rise to 8-16 fimbria which surround and embrace the nucleus. Immunogold labeling indicates that these fimbria are juxtaposed to the outer nuclear envelope. Earlier studies have demonstrated that the centrin-based linkage between the flagellar apparatus and the nucleus is contractile, both in vitro and in living Chlamydomonas cells (Wright, R. L., J. Salisbury, and J. Jarvik. 1985. J. Cell Biol. 101:1903-1912; Salisbury, J. L., M. A. Sanders, and L. Harpst. 1987. J. Cell Biol. 105:1799-1805). Immunofluorescence studies show dramatic changes in distribution of the centrin-based system during mitosis that include a transient contraction at preprophase; division, separation, and re-extension during prophase; and a second transient contraction at the metaphase/anaphase boundary. These observations suggest a fundamental role for centrin in motile events during mitosis.

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Spermatogenesis and the fine structure of the mature spermatozoon of the liver fluke, Fasciola hepatica (Trematoda: Digenea)

Parasitology ◽

10.1017/s0031182000060595 ◽

1990 ◽

Vol 101 (3) ◽

pp. 395-407 ◽

Cited By ~ 45

Author(s):

A. W. Stitt ◽

I. Fairweather

Keyword(s):

Fine Structure ◽

Liver Fluke ◽

Central Body ◽

Fasciola Hepatica ◽

Mature Spermatozoon ◽

Basal Bodies ◽

Nuclear Region ◽

Sperm Ultrastructure ◽

Transmission Electron ◽

Median Process

SUMMARYSpermatogenesis and the fine structure of the mature spermatozoon of Fasciola hepatica have been studied by transmission electron microscopy. The primary spermatogonia display a typical gonial morphology and occupy the periphery of the testis. They undergo 3 mitotic divisions to give rise to 8 primary spermatocytes forming a rosette of cells connected to a central cytophore. The primary spermatocytes undergo 2 meiotic divisions, resulting in 32 spermatids that develop into spermatozoa. Intranuclear synaptonemal complexes in primary spermatocytes confirm the first meiotic division. The onset of spermiogenesis is marked by the formation of the zone of differentiation which contains 2 basal bodies and a further centriole derivative, the central body. The zone extends away from the spermatid cell to form the median process; into this migrates the differentiated and elongate nucleus. Simultaneously, 2 axonemes develop from the basal bodies. During development, they rotate through 90° to extend parallel to the median process. The migration of the nucleus to the distal end of the median process coincides with the fusion of the axonemes to the latter to form a monopartite spermatozoon. The mature spermatozoon possesses 2 axonemes of the 9 + ‘1’ pattern typical of parasitic platyhelminths, 2 elongate mitochondria and a variable array of peripheral microtubules. The nuclear region of the spermatozoon is immotile. The value of sperm ultrastructure as a taxonomic tool in platyhelminth phylogeny is discussed.

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Centrin2 regulates CP110 removal in primary cilium formation

The Journal of Cell Biology ◽

10.1083/jcb.201411070 ◽

2015 ◽

Vol 208 (6) ◽

pp. 693-701 ◽

Cited By ~ 38

Author(s):

Suzanna L. Prosser ◽

Ciaran G. Morrison

Keyword(s):

Calcium Binding ◽

Primary Cilia ◽

Reverse Genetics ◽

Cell Types ◽

Serum Starvation ◽

Basal Bodies ◽

Cilium Formation ◽

Cellular Quiescence ◽

Retinal Pigmented Epithelial Cells

Primary cilia are antenna-like sensory microtubule structures that extend from basal bodies, plasma membrane–docked mother centrioles. Cellular quiescence potentiates ciliogenesis, but the regulation of basal body formation is not fully understood. We used reverse genetics to test the role of the small calcium-binding protein, centrin2, in ciliogenesis. Primary cilia arise in most cell types but have not been described in lymphocytes. We show here that serum starvation of transformed, cultured B and T cells caused primary ciliogenesis. Efficient ciliogenesis in chicken DT40 B lymphocytes required centrin2. We disrupted CETN2 in human retinal pigmented epithelial cells, and despite having intact centrioles, they were unable to make cilia upon serum starvation, showing abnormal localization of distal appendage proteins and failing to remove the ciliation inhibitor CP110. Knockdown of CP110 rescued ciliation in CETN2-deficient cells. Thus, centrin2 regulates primary ciliogenesis through controlling CP110 levels.

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MITOSIS IN DUNALIELLA BIOCULATA (CHLOROPHYTA): CENTRIN BUT NOT BASAL BODIES ARE AT THE SPINDLE POLES

Journal of Phycology ◽

10.1046/j.1529-8817.2001.01089.x ◽

2001 ◽

Vol 37 (6) ◽

pp. 1030-1043 ◽

Cited By ~ 3

Author(s):

Andrea Grunow ◽

Karl‐Ferdinand Lechtreck

Keyword(s):

Basal Bodies ◽

Spindle Poles

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