scholarly journals The Microtubule Cytoskeleton during the Early Drosophila Spermiogenesis

Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2684
Author(s):  
Maria Giovanna Riparbelli ◽  
Veronica Persico ◽  
Giuliano Callaini
Keyword(s):  
Basal Body ◽  
Anterior Pole ◽  
Microtubule Cytoskeleton ◽  
Nuclear Shaping ◽  
Pericentriolar Material ◽  
Centriole Adjunct ◽  
Shed Light

Sperm elongation and nuclear shaping in Drosophila largely depends on the microtubule cytoskeleton that in early spermatids has centrosomal and non-centrosomal origins. We report here an additional γ-tubulin focus localized on the anterior pole of the nucleus in correspondence of the apical end of the perinuclear microtubules that run within the dense complex. The perinuclear microtubules are nucleated by the pericentriolar material, or centriole adjunct, that surrounds the basal body and are retained to play a major role in nuclear shaping. However, we found that both the perinuclear microtubules and the dense complex are present in spermatids lacking centrioles. Therefore, the basal body or the centriole adjunct seem to be dispensable for the organization and assembly of these structures. These observations shed light on a novel localization of γ-tubulin and open a new scenario on the distribution of the microtubules and the organization of the dense complex during early Drosophila spermiogenesis.

scholarly journals Asterless is required for centriole length control and sperm development

2016 ◽  
Vol 213 (4) ◽  
pp. 435-450 ◽  
Author(s):  
Brian J. Galletta ◽  
Katherine C. Jacobs ◽  
Carey J. Fagerstrom ◽  
Nasser M. Rusan
Keyword(s):  
Drosophila Melanogaster ◽  
Basal Body ◽  
Somatic Tissue ◽  
Mitotic Spindles ◽  
Independent Function ◽  
Centriole Duplication ◽  
Sperm Development ◽  
Pericentriolar Material ◽  
Shed Light

Centrioles are the foundation of two organelles, centrosomes and cilia. Centriole numbers and functions are tightly controlled, and mutations in centriole proteins are linked to a variety of diseases, including microcephaly. Loss of the centriole protein Asterless (Asl), the Drosophila melanogaster orthologue of Cep152, prevents centriole duplication, which has limited the study of its nonduplication functions. Here, we identify populations of cells with Asl-free centrioles in developing Drosophila tissues, allowing us to assess its duplication-independent function. We show a role for Asl in controlling centriole length in germline and somatic tissue, functioning via the centriole protein Cep97. We also find that Asl is not essential for pericentriolar material recruitment or centrosome function in organizing mitotic spindles. Lastly, we show that Asl is required for proper basal body function and spermatid axoneme formation. Insights into the role of Asl/Cep152 beyond centriole duplication could help shed light on how Cep152 mutations lead to the development of microcephaly.

Gamma-tubulin reorganization during mouse fertilization and early development

1993 ◽  
Vol 104 (2) ◽  
pp. 383-389 ◽  
Author(s):  
M.J. Palacios ◽  
H.C. Joshi ◽  
C. Simerly ◽  
G. Schatten
Keyword(s):  
Early Development ◽  
Basal Body ◽  
Spindle Pole ◽  
Meiotic Spindle ◽  
Cytoplasmic Microtubule ◽  
Mouse Oocytes ◽  
Spindle Pole Bodies ◽  
Preimplantation Stage ◽  
Pericentriolar Material ◽  
Gamma Tubulin

gamma-Tubulin, a component of spindle pole bodies in fungal cells and pericentriolar material in vertebrate cells, is thought to play a role in the nucleation of microtubule growth and to define their polarity. In contrast to the adult somatic cells, microtubules are nucleated in the absence of centrioles in mammalian oocytes and early embryos. By studying acentriolar mouse oocytes and their early development following fertilization, we show that gamma-tubulin antibody crossreacts with a 50,000 M(r) protein in unfertilized mouse oocytes and demonstrate that gamma-tubulin distribution is rearranged dramatically during fertilization. In unfertilized mouse oocytes, gamma-tubulin is concentrated in the broad spindle poles of meiotic spindle (MII) and as the distinct foci which form the centers of the cytoplasmic microtubule asters (cytasters). The integrity of these gamma-tubulin foci and their cytoplasmic location is maintained during the drug- or cold-induced depolymerization of microtubules. gamma-Tubulin is also found in the basal body of the mouse sperm. During fertilization, the gamma-tubulin is found at the cytastral centers as well as in the incorporated sperm basal body complex, and the gamma-tubulin foci coalesce at the perinuclear microtubule organizing regions of the two pronuclei at the first mitotic prophase. During mitosis, gamma-tubulin is found associated with broad bands that form the poles of the first mitotic spindle. By the late preimplantation stage, when newly generated centrioles have been reported to arise, gamma-tubulin remains localized at the centrosome of mitotic cells.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Regulating the transition from centriole to basal body

2011 ◽  
Vol 193 (3) ◽  
pp. 435-444 ◽  
Author(s):  
Tetsuo Kobayashi ◽  
Brian D. Dynlacht
Keyword(s):  
Cell Cycle ◽  
Basal Body ◽  
Primary Cilia ◽  
Molecular Mechanisms ◽  
Basal Bodies ◽  
Spindle Poles ◽  
Shed Light

The role of centrioles changes as a function of the cell cycle. Centrioles promote formation of spindle poles in mitosis and act as basal bodies to assemble primary cilia in interphase. Stringent regulations govern conversion between these two states. Although the molecular mechanisms have not been fully elucidated, recent findings have begun to shed light on pathways that regulate the conversion of centrioles to basal bodies and vice versa. Emerging studies also provide insights into how defects in the balance between centrosome and cilia function could promote ciliopathies and cancer.

Microtubules: greater than the sum of the parts

2013 ◽  
Vol 41 (6) ◽  
pp. 1736-1744 ◽  
Author(s):  
Jonathan L.D. Lawson ◽  
Rafael E. Carazo Salas
Keyword(s):  
Environmental Changes ◽  
Super Resolution ◽  
Integrative Approach ◽  
Microtubule Cytoskeleton ◽  
Cellular Processes ◽  
Interdisciplinary Approaches ◽  
High Degree ◽  
Super Resolution Microscopy ◽  
Shed Light

The post-genomic era has produced a variety of new investigation technologies, techniques and approaches that may offer exciting insights into many long-standing questions of scientific research. The microtubule cytoskeleton is a highly conserved system that shows a high degree of internal complexity, is known to be integral to many cell systems and functions on a fundamental level. After decades of study, much is still unknown about microtubules in vivo from the control of dynamics in living cells to their responses to environmental changes and responses to other cellular processes. In the present article, we examine some outstanding questions in the microtubule field and propose a combination of emerging interdisciplinary approaches, i.e. high-throughput functional genomics techniques, quantitative and super-resolution microscopy, and in silico modelling, that could shed light on the systemic regulation of microtubules in cells by networks of regulatory factors. We propose that such an integrative approach is key to elucidate the function of the microtubule cytoskeleton as a complete responsive integral biological system.

scholarly journals Naegleria gruberi De Novo Basal Body Assembly Occurs via Stepwise Incorporation of Conserved Proteins

2010 ◽  
Vol 9 (6) ◽  
pp. 860-865 ◽  
Author(s):  
Lillian K. Fritz-Laylin ◽  
Zoe June Assaf ◽  
Sean Chen ◽  
W. Zacheus Cande
Keyword(s):  
Basal Body ◽  
De Novo ◽  
Unicellular Eukaryote ◽  
Basal Bodies ◽  
Microtubule Cytoskeleton ◽  
Cytoplasmic Microtubule ◽  
Content Type ◽  
Genes Encoding ◽  
Associated Proteins ◽  
Naegleria Gruberi

ABSTRACT Centrioles and basal bodies are discrete structures composed of a cylinder of nine microtubule triplets and associated proteins. Metazoan centrioles can be found at mitotic spindle poles and are called basal bodies when used to organize microtubules to form the core structure of flagella. Naegleria gruberi, a unicellular eukaryote, grows as an amoeba that lacks a cytoplasmic microtubule cytoskeleton. When stressed, Naegleria rapidly (and synchronously) differentiates into a flagellate, forming a complete cytoplasmic cytoskeleton de novo, including two basal bodies and flagella. Here, we show that Naegleria has genes encoding conserved centriole proteins. Using novel antibodies, we describe the localization of three centrosomal protein homologs (SAS-6, γ-tubulin, and centrin-1) during the assembly of the flagellate microtubule cytoskeleton. We also used these antibodies to show that Naegleria expresses the proteins in the same order as their incorporation into basal bodies, with SAS-6 localizing first, followed by centrin and finally γ-tubulin. The similarities between basal body assembly in Naegleria and centriole assembly in animals indicate that mechanisms of assembly, as well as structure, have been conserved throughout eukaryotic evolution.

The three-dimensional structure of frozen-hydrated left- and right-handed forms of bacterial flagellar filaments from an identical serotype

1986 ◽  
Vol 44 ◽  
pp. 298-299
Author(s):  
S. Trachtenberg ◽  
D. J. DeRosier
Keyword(s):  
Ionic Strength ◽  
Basal Body ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Protein Species ◽  
Liquid Environment ◽  
Bacterial Flagellum ◽  
Left And Right ◽  
Rotary Motor ◽  
Helical Parameters

The bacterial cell is propelled through the liquid environment by means of one or more rotating flagella. The bacterial flagellum is composed of a basal body (rotary motor), hook (universal coupler), and filament (propellor). The filament is a rigid helical assembly of only one protein species — flagellin. The filament can adopt different morphologies and change, reversibly, its helical parameters (pitch and hand) as a function of mechanical stress and chemical changes (pH, ionic strength) in the environment.

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

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.

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

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.

Elucidating cyclic AMP signaling in subcellular domains with optogenetic tools and fluorescent biosensors

2019 ◽  
Vol 47 (6) ◽  
pp. 1733-1747 ◽  
Author(s):  
Christina Klausen ◽  
Fabian Kaiser ◽  
Birthe Stüven ◽  
Jan N. Hansen ◽  
Dagmar Wachten
Keyword(s):  
Cyclic Amp ◽  
Adenosine Monophosphate ◽  
Adenylyl Cyclases ◽  
Temporal Precision ◽  
Fluorescent Biosensors ◽  
Subcellular Domains ◽  
Spatio Temporal ◽  
Hydrolysis Of ◽  
Shed Light ◽  
Cyclic Amp Signaling

The second messenger 3′,5′-cyclic nucleoside adenosine monophosphate (cAMP) plays a key role in signal transduction across prokaryotes and eukaryotes. Cyclic AMP signaling is compartmentalized into microdomains to fulfil specific functions. To define the function of cAMP within these microdomains, signaling needs to be analyzed with spatio-temporal precision. To this end, optogenetic approaches and genetically encoded fluorescent biosensors are particularly well suited. Synthesis and hydrolysis of cAMP can be directly manipulated by photoactivated adenylyl cyclases (PACs) and light-regulated phosphodiesterases (PDEs), respectively. In addition, many biosensors have been designed to spatially and temporarily resolve cAMP dynamics in the cell. This review provides an overview about optogenetic tools and biosensors to shed light on the subcellular organization of cAMP signaling.

Sentence-Based Experience Logging in New Hearing Aid Users

2020 ◽  
Vol 29 (3S) ◽  
pp. 631-637
Author(s):  
Katja Lund ◽  
Rodrigo Ordoñez ◽  
Jens Bo Nielsen ◽  
Dorte Hammershøi
Keyword(s):  
Hearing Aid ◽  
Patient Experiences ◽  
Online Tool ◽  
Rehabilitation Process ◽  
Hearing Rehabilitation ◽  
Clinical Observations ◽  
Hearing Aid Use ◽  
Wide Range ◽  
Insight Into ◽  
Shed Light

Purpose The aim of this study was to develop a tool to gain insight into the daily experiences of new hearing aid users and to shed light on aspects of aided performance that may not be unveiled through standard questionnaires. Method The tool is developed based on clinical observations, patient experiences, expert involvement, and existing validated hearing rehabilitation questionnaires. Results An online tool for collecting data related to hearing aid use was developed. The tool is based on 453 prefabricated sentences representing experiences within 13 categories related to hearing aid use. Conclusions The tool has the potential to reflect a wide range of individual experiences with hearing aid use, including auditory and nonauditory aspects. These experiences may hold important knowledge for both the patient and the professional in the hearing rehabilitation process.

Sign in / Sign up

Export Citation Format

Share Document