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Familial immotile-cilia syndrome in English springer spaniel dogs.

A laboratory-maintained colony of English springer spaniel dogs heterozygous for a putative autosomal recessive immotile-cilia syndrome (ICS) has been studied. Matings between dogs thought to be heterozygous for ICS resulted in 22 pups, five (three males and two females) of which were homozygous for ICS. Four of the five ICS-affected dogs had chronic rhinitis and bronchopneumonia. The other dog had a serious nasal discharge and died at 10 days. Four dogs had situs inversus totalis (kartagener syndrome), and the two males of reproductive age were azoospermic. In the two ICS dogs studied for ciliary function, in vivo mucociliary clearance was absent, and in vitro ciliary beat was rarely observed and of low frequency. Scanning and transmission electron microscopy disclosed the same lesions in respiratory cilia from all dogs with ICS, including random orientation and partial outer dynein arm deficiency. Four of five dogs with ICS had dilated lateral ventricles. One female pup with neonatal rhinitis and bronchopneumonia, situs solitus, and dilated lateral ventricles was presumed to be homozygous for ICS, but died without functional or structural confirmation of defective respiratory cilia. An autosomal recessive mode of inheritance for the ciliary defects and respiratory signs of ICS in these dogs is proposed.

Animals↗

Ultrastructure of melanocytes in the dark cell area of human vestibular organs: functional implications of gap junctions, isolated cilia, and annulate lamellae.

BACKGROUND: It is known that melanocytes exist in almost all parts of the inner ear, such as the cochlear duct, stria vascularis, Reissner's membrane, modiolus, vestibular organs in the region surrounding the cristae and maculae, semicircular canals, and pars rugosa of the endolymphatic sac. But there have been few studies using human materials, because of the difficulty of obtaining materials. We attempted to investigate the detailed ultrastructure of melanocytes in the vestibular organs of human inner ear. METHODS: Eight surgical specimens obtained from patients with vestibular schwannoma were studied by light microscopy and electron microscopy. RESULTS: Melanocytes were found in the subepithelial layer of the dark cell area. Melanocytes had round or spindle-shaped nuclei and clear cytoplasm with brown pigment granules. Besides melanocytes, there were melanophages, fibroblasts, and small blood vessels. Through electron microscopy we found melanocytes with round-shaped melanosomes in various stages of pigmentation, well-developed Golgi apparatus and endoplasmic reticulum in the cytoplasm, and many cytoplasmic processes. Gap junctions were occasionally found between the cytoplasmic processes. And there were pinocytotic vesicles just under the limiting membrane of melanocytes, and intermediate filaments were abundant in the cytoplasm. Isolated cilia of melanocytes, annulate lamellae, and fusiform banded structures in the connective tissue area around melanocytes were found. CONCLUSIONS: Melanocytes in human vestibular organs actively synthesize melanosomes. Frequent findings of isolated cilia and fusiform banded structures and the incidental existence of annulate lamellae may be an indicator of this metabolically activated state of melanocytes. Moreover, monitoring environmental changes by isolated cilia, melanocytes in the human inner ear could act not only as one cell but also as a group to achieve their physiological functions by means of information transmission through gap junctions.

Adult↗

Computer simulation of flagellar movement IX. Oscillation and symmetry breaking in a model for short flagella and nodal cilia.

A computer model of flagella in which oscillation results from regulation of active sliding force by sliding velocity can simulate the movements of very short flagella and cilia. Of particular interest are the movements of the short (2-3 microm) nodal cilia of the mammalian embryo, which determine the development of the asymmetry of the internal organs. These cilia must generate a counterclockwise (viewed from base to tip) circling motion. A three-dimensional computer model, with active force generated by a simple mathematical formulation and regulated by sliding velocity, can generate this circling motion if a time delay process is included in the control specification. Without the introduction of a symmetry-breaking mechanism, the computer models start randomly in either direction, and maintain either clockwise or counterclockwise circling. Symmetry can be broken by at least two mechanisms: (1) control of dynein activity on one outer doublet by sliding velocity can be influenced by the sliding velocity experienced on an adjacent outer doublet, or (2) a constant twist of the axoneme caused by an off-axis component of dynein force. This second mechanism appears more reasonable, but its effectiveness is highly dependent upon specifications for the elastic resistances of the model. These symmetry-breaking mechanisms need to be present only at the beginning of circling. With these models, once a circling direction is established, it remains stable even if the symmetry-breaking mechanism is removed.

Animals↗

Identification of a novel actin-related protein in Tetrahymena cilia.

Actin is an ancient cytoskeletal protein that plays many essential roles in cell motility. In eukaryotes, its gene belongs to a highly conserved gene family, while the protein is also a member of an actin superfamily comprising various kinds of actin-related proteins (Arps). A ciliate, Tetrahymena, has a unique conventional actin. Data from the TIGR Tetrahymena genome project and our own research suggest the existence of 12 actin-like sequences: four conventional actins, two of Arp4, one each of Arp1, Arp2, Arp3, Arp5, and Arp6, and a novel actin-related protein, tArp. We cloned the entire cDNA sequences of Tetrahymena Arp2 (tArp2), Tetrahymena Arp3 (tArp3), and tArp for the work described herein. In phylogenetic analyses, tArp was not included in any Arp subfamily. Unlike other known Arps, tArp localizes in cilia, and its expression was upregulated after deciliation. To see the precise localization of tArp, cilia were fractionated and analyzed using specific antibodies. tArp was observed preferentially in the "outer-doublet" fraction, while actin was found in the "crude-dynein" fraction. In immunoelectron microscopy, most of the gold particles were found either on the outer-doublet or central-pair microtubules. These results suggest that tArp is a ciliary component and that it has a unique function in the formation and maintenance of cilia.

Actin-Related Protein 2↗

Utilization of digital image processing to study dynein arms (ATPase) in normal and immotile cilia.

Tracheal ciliary cross sections were examined with scanning transmission electron microscopy and the resultant images were digitized for image enhancement. A gray-scale histogram of each ciliary image was produced and manipulated to enhance the image for dynein arms. Tracheal epithelial tissue from the pig, rabbit, and dog, including dogs with immotile cilia syndrome, was examined by using this technique. Tissue from each animal was fixed with each of three different fixatives and sections were evaluated for preservation of dynein arms. The same fixative did not consistently provide optimal fixation for ciliary dynein arms in all three species examined. Each species, therefore, must be evaluated to determine the optimal fixative for preservation of normal ciliary ultrastructure. Digital image processing provides a mechanism for enhancing dynein arms in situ without the need for addition of special stains or the use of techniques such as image summation. With this technique it has been shown that about two-thirds of outer dynein arms are partially or completely missing on cilia from dogs with immotile cilia syndrome.

Adenosine Triphosphatases↗

Effect of vanadate on gill cilia: switching mechanism in ciliary beat.

Lateral (L) cilia of freshwater mussel (Margaritana margaritifera and Elliptio complanatus) gills can be arrested in one of two unique positions. When treated with 12.5 mM CaCl2 and 10(-5) M A23187 they arrest in a "hands up" position, ie, pointing frontally. When treated with approximately 10 mM vanadate (V) they arrest in a "hands down" position, ie, pointing abfrontally. L-cilia treated with 12.5 mM CaCl2 and 1 mM NaN3 also arrest in a "hands down" position; substitution of 20 mM KCl and 1 mM NaN3 causes cilia to move rapidly and simultaneously to a "hands up" position. The observations suggest that there are two switching mechanisms for activation of active sliding in ciliary beat one at the end of the recovery stroke and the other at the end of the effective stroke; the first is inhibited by calcium and the second by vanadate or azide. This is consistent with a model of ciliary beating where microtubule doublet numbers 1, 2, 3, and 4 are active during the effective stroke while microtubule doublets numbers 6, 7, 8, and 9 are passive, and the converse occurs during the recovery stroke.

Animals↗

Ciliary dyskinesis: the immotile cilia syndrome.

In the past 5 years much has been learned about the syndrome of ciliary dyskinesia, commonly referred to as immotile cilia syndrome. This syndrome appears to be a congenital defect in the ultrastructure of the cilia, which results in one of three basic defects; lack of dynein arms, absence of radial spokes, or transposition of microtubules. Three cases are presented with electron micrographs; they illustrate the diverse clinical presentations of this disease entity as well as some of the structural abnormalities. The normal and abnormal anatomy of the cilia is discussed and some explanation is offered as to why these structural abnormalities present with such a variety of clinical expressions.

Adult↗

Presence of multiple centrioles and primary cilia during growth and early differentiation in the myoblast CO25 cell line.

CO25 cells, a mouse myoblast line, contain multiple centrioles and primary cilia. A most unusual feature has been the finding of large numbers of separate structures in single cells-up to a maximum of nine centrioles, six primary cilia, and 12 of both organelles together. Aberrant multipolar spindles were occasionally seen containing variable numbers of centrioles. This strongly suggests that cells containing supernumerary centrioles and cilia are lost during mitosis, and that additional centriolar structures are generated during each interphase. No change in centriole or primary cilium frequency was detected after inducing the differentiation of myoblasts into myotubes. However, a significant migration of these structures occurred from a perinuclear to a supranuclear position prior to and during the phase of myoblast elongation. This shift was not maintained during cell fusion, when a net migration back to the periphery was observed, suggesting that it may have some function in relation to cell elongation and the change in the pattern of microtubule distribution which occurs as part of the process.

Animals↗

Scanning and transmission electron microscopic findings in cilia from human nasal turbinate and sinus mucosa following respiratory infection.

Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to study the ultrastructure of human respiratory cilia in 34 patients with chronic or recurrent respiratory infections and 11 control patients. Specimens of pathological mucosa were taken from 12 maxillary sinuses and 22 middle turbinates. Control tissues were taken from middle turbinates or from sphenoid sinuses during transsphenoidal pituitary surgery. Findings in control tissues or specimens with minimal amounts of pathological findings showed that TEM and SEM findings correlated well. TEM revealed axoneme structure better, while much larger populations of cilia could be studied three-dimensionally with SEM. SEM also was the better study when cilia orientations or lengths were evaluated. Optimal examination of ciliary ultrastructure required both TEM and SEM studies.

Adolescent↗

Frequency of occurrence and position of cilia in fibroblasts of the periodontal ligament of the mouse incisor.

Solitary cilia occur in motile as well as in non-motile fibroblasts of the peridontal ligament. The cells which moved with the erupting incisor are bipolar and oriented with their long axes parallel to the tooth surface. In cross section these cells have a flattened appearance. Cilia are localized in close vicinity to the nuclear area and show a definite orientation with respect to the transverse cell axis. The frequency of occurrence of this organelle was estimated from the percentage of diplosomes containing a basal body. Analysis of the composition of the paired structures indicated that at least 70 per cent of the fibroblasts are ciliated. The frequency of cilia in motile fibroblasts does not differ from that in non-motile cells suggesting that the presence of this organelle is not directly associated with cell locomotion.

Animals↗

HLA haplotype segregation and ultrastructural study in familial immotile-cilia syndrome.

The immotile-cilia syndrome (ICS) is a congenital disorder characterized by dysmotility or even complete immotility of the cilia in the ciliated epithelia. The most frequent consequences include recurrent airway infections from early childhood. Neonatal asphyxia often occurs. Males are usually sterile, whereas females may be fertile or infertile. The disease is inherited as an autosomal recessive trait, but previous attempts to localize the ICS susceptibility gene have so far been unsuccessful. Here, we present the case of two sib pairs affected by ICS from two unrelated families. The electron microscopic investigation of nasal biopsies showed structural anomalies of the cilia, characterized by single microtubules or doublets, arranged randomly in the axoneme. Histocompatibility antigen (HLA)-genotyping of all family members revealed: 1) a significant association of ICS with the HLA-DR7; DQW2 haplotype, which is shared by all the affected sibs (P = 0.0099; RR = 25.94); 2) a possible linkage of the ICS susceptibility gene with HLA, both the affected sibs being HLA-identical, the healthy brother in family B being HLA-different (sib-pair analysis: P less than 0.001).

Child, Preschool↗

The immotile cilia syndrome. Mice versus man.

When homozygous the recessive, pleiotropic, mutation hpy (hydrocephalic-polydactyl) produces post-natal hydrocephalus, complete sterility in males, and reduced reproductive performance in females. Because the fertility problems and the development of hydrocephalus could arise as consequences of defective flagella and ciliary axonemes, this mutant type might serve as a useful animal model for the immotile cilia syndrome. Ultrastructural defects seen in axonemes of flagella, and of cilia from the trachea, oviduct, and ependyma included: a deficiency of inner dynein arms (the most frequent defect); an absence of one or both central-pair tubules; extra central tubules; a displacement of one outer doublet and/or the central-pair tubules. Some axonemes showed more than one of these defects. The frequency of dynein-deficient axonemes in all three tissues was similar (about 35%) and fell within the range reported for human patients with the immotile cilia syndrome. On this basis, this mutant type might be considered as a useful animal model for such studies. There were no indications of situs inversus, nor was there a marked increase in respiratory problems. So hpy/hpy mice do not exhibit all of the clinical symptoms characteristic of the human condition.

Animals↗

Insulin pretreatment (imprinting) produces elevated capacity in the insulin binding of Tetrahymena. Different binding by the cilia of the body and oral field.

Gold-labeled insulin is bound first of all to the cilia of the oral field of Tetrahymena. A primary treatment (hormonal imprinting) with insulin increases the binding capacity even after 24h and makes it more sensitive for appearance a week later, within a minute of giving insulin-gold. The food vacuoles contain insulin-gold in pretreated cells or without pretreatment as well, though in imprinted situations the label can be found in pinocytotic vesicles at the bases of cilia in the oral field. Altogether, a functional difference can be observed between the cilia of the oral and non-oral surfaces of Tetrahymena and hormonal imprinting has a specifying effect on the binding of labeled hormone.

Animals↗

Endogenous lectin CSL is present on the membrane of cilia of rat brain ependymal cells.

An endogenous brain lectin, with a great affinity for oligomannosidic glycans, called CSL (for 'cerebellar soluble lectin'), was detected on the surface of the cilia of ependymal cells both in cultures and in vivo. The lectin is not synthesized by the ependymal cells themselves. In vivo it is neither found in cerebrospinal fluid nor in cells of the choroid plexus. Probably, lectin CSL is produced by subependymal astrocytic cells. The membranes of ependymal cells seem to possess glycoprotein ligands for the lectin which explain the specific adhesion of CSL on the surface of these cells, particularly on the cilia. The localization of this adhesive molecule on cilia of ependymal cells suggests that it may play a role in trapping foreign cells, micro-organisms or debris.

Animals↗

Large olfactory responses of the carp after complete removal of olfactory cilia.

To study the role of olfactory cilia on olfactory reception, the carp olfactory cilia were removed by modified "ethanol-calcium shock" and the bulbar responses were recorded before and after deciliation. Large olfactory responses to various amino acids were observed after complete deciliation. The relation between magnitude of olfactory response and alanine concentration before and after deciliation was essentially unchanged. The present results suggests that the olfactory cilia may not be necessary for receptor neuron function in the carp.

Animals↗

Ciliary motility in the 'immotile cilia syndrome'. First results of microphoto-oscillographic studies.

Using a microphoto-oscillographic technique the authors studied ciliary beating of nasal epithelial cells from 11 patients with the 'immotile cilia syndrome' (Kartagener's syndrome) and from normal controls. Ciliary motility was found in all patients, except one. Although the patients had a significantly reduced number of cells with motile cilia, one-third of all ciliated cells showed motility. The beating frequency was normal, but the motility pattern was highly abnormal, with a predominance of asynchronous motility in the patients. These results suggest that the lack of dynein arms in cilia in these patients only is partial and that direct observation of ciliated cells, obtained by gentle scraping on the nasal mucosa, may be a suitable screening test for early diagnosis of this syndrome.

Adolescent↗

The morphology of cilia in sponge larvae.

Sponge larvae posses cillia with unusual terminal expansions which are curled or biconcave in shape externally, as seen by scanning electron microscopy. Thin sections, passing through the point where the ciliary shaft enters the expanded area reveal the ciliary axoneme to be surrounded by many membranous folds, some of which are vesicular. The 'club footed' cilia occur in disparate groups of Demospongiae and most frequently, all larval cilia are of this type. There is no immediately obvious correlation between the type of movement displayed by the larvae and the occurrence of terminally expanded cilia.

Animals↗