Composition and function of the C1b/C1f region in the ciliary central apparatus.

Motile cilia are ultrastructurally complex cell organelles with the ability to actively move. The highly conserved central apparatus of motile 9 × 2 + 2 cilia is composed of two microtubules and several large microtubule-bound projections, including the C1b/C1f supercomplex. The composition and function of C1b/C1f subunits has only recently started to emerge. We show that in the model ciliate Tetrahymena thermophila, C1b/C1f contains several evolutionarily conserved proteins: Spef2A, Cfap69, Cfap246/LRGUK, Adgb/androglobin, and a ciliate-specific protein Tt170/TTHERM_00205170. Deletion of genes encoding either Spef2A or Cfap69 led to a loss of the entire C1b projection and resulted in an abnormal vortex motion of cilia. Loss of either Cfap246 or Adgb caused only minor alterations in ciliary motility. Comparative analyses of wild-type and C1b-deficient mutant ciliomes revealed that the levels of subunits forming the adjacent C2b projection but not C1d projection are greatly reduced, indicating that C1b stabilizes C2b. Moreover, the levels of several IFT and BBS proteins, HSP70, and enzymes that catalyze the final steps of the glycolytic pathway: enolase ENO1 and pyruvate kinase PYK1, are also reduced in the C1b-less mutants.

Classificação clínica de ptose da cauda do supercílio / Clinical classification of brow ptosis

INTRODUÇÃO: O estudo do supercílio se emoldura como um grande desafio para a cirurgia plástica por sua complexa relação com as estruturas faciais. O objetivo é descrever uma classificação clínica de ptose da cauda do supercílio. MÉTODOS: Estudo transversal, com pacientes de ambos os sexos, com idade de 18 a 100 anos, subdivididos em três grupos segundo a faixa etária. Grupo 1: 18 a 30 anos, Grupo 2: 31 a 60 anos e Grupo 3: 61 a 100 anos. Realizaram-se três medidas de cada lado por examinadores distintos, sem que cada um soubesse o valor da aferição dos demais. RESULTADOS: Total de 90 pacientes, com idades variando entre 18 e 94 anos, sendo 39 (43,3%) do sexo masculino e 51 (56,7%)do sexo feminino. As medidas do Grupo 1, considerado como normal, com média de idade de 26,7 anos, e com média de 2,14 cm em relação a medidas da ptose da cauda do supercílio. Já no Grupo 2, média da faixa etária foi de 44,2 anos e a média foi de 1,9 cm. No Grupo 3, média de idade de 72,6 anos com média de 1,27 cm. A tabela com a Classificação da Ptose da Cauda do Supercílio, em que se atribuiu a cada intervalo um grau de ptose, variando de grau I ao grau IV. Cada grau foi correlacionado com um intervalo numérico em que: > 1,8 cm representa a normalidade; 1,7-1,5 cm o grau I de ptose; 1,4-1,2 cm o grau II de ptose;1,1-0,9 cm o grau III de ptose e < 0,8 cm o grau IV de ptose. Em referência à indicação cirúrgica, essa teve sua indicação nos graus II, III e IV. CONCLUSÃO: A medida objetiva da posição da cauda do supercílio possibilitou classificação do grau de ptose e orientação quanto à necessidade de intervenção cirúrgica.

INTRODUCTION: The study of the eyebrow is a great challenge for plastic surgery because of its complex relationship with facial structures. The present study aims to describe a clinical classification of brow ptosis. METHODS: A cross-sectional study with patients of both sexes and ages ranging from 18 to 100 years, subdivided into 3 groups according to age. Group 1: 18 to 30 years of age, Group 2: 31 to 60 years of age, and Group 3: 61 to 100 years of age. Three measurements were taken on each side by different examiners blinded to each other's results. RESULTS: A total of 90 patients, with ages ranging from 18 to 94, including 39 (43.3%) men and 51 (56.7%) women, were studied. Group 1, with a mean age of 26.7 years was considered normal, with mean brow ptosis of 2.14 cm. In Group 2, with a mean age of 44.2 years, the mean brow measurement was 1.9 cm. In Group 3, the mean age was 72.6 years and the mean brow measurement was 1.27 cm. The table outlining the brow ptosis classification assigns a degree of ptosis to each interval, ranging from I to IV. Each degree was correlated with a numerical range in which > 1.8 cm is normal, 1.7-1.5 cm corresponds to degree I ptosis, 1.4-1.2 cm to degree II ptosis, 1.1-0.9 cm to degree III ptosis, and < 0.8 cm to degree IV ptosis. Surgery was indicated for degrees II, III, and IV. CONCLUSION: The objective measurement of brow tail position enabled classification of the degree of ptosis and guides surgical decision-making.

Three types of ependymal cells with intracellular calcium oscillation are characterized by distinct cilia beating properties.

Ependymal cells are multiciliated epithelial cells that line the ventricles in the adult brain. Abnormal function or structure of ependymal cilia has been associated with various neurological deficits. For the first time, we report three distinct ependymal cell types, I, II, and III, based on their unique ciliary beating frequency and beating angle. These ependymal cells have specific localizations within the third ventricle of the mouse brain. Furthermore, neither ependymal cell types nor their localizations are altered by aging. Our high-speed fluorescence imaging analysis reveals that these ependymal cells have an intracellular pacing calcium oscillation property. Our study further shows that alcohol can significantly repress the amplitude of calcium oscillation and the frequency of ciliary beating, resulting in an overall decrease in volume replacement by the cilia. Furthermore, the pharmacological agent cilostazol could differentially increase cilia beating frequency in type II, but not in type I or type III, ependymal cells. In summary, we provide the first evidence of three distinct types of ependymal cells with calcium oscillation properties.

Centrioles: active players or passengers during mitosis?

Centrioles are cylinders made of nine microtubule (MT) triplets present in many eukaryotes. Early studies, where centrosomes were seen at the poles of the mitotic spindle led to their coining as "the organ for cell division". However, a variety of subsequent observational and functional studies showed that centrosomes might not always be essential for mitosis. Here we review the arguments in this debate. We describe the centriole structure and its distribution in the eukaryotic tree of life and clarify its role in the organization of the centrosome and cilia, with an historical perspective. An important aspect of the debate addressed in this review is how centrioles are inherited and the role of the spindle in this process. In particular, germline inheritance of centrosomes, such as their de novo formation in parthenogenetic species, poses many interesting questions. We finish by discussing the most likely functions of centrioles and laying out new research avenues.

Centrioles want to move out and make cilia.

Cilia formation in mammalian cells requires basal bodies that are either derived from centrioles that transition from their cytoplasmic role in centrosome organization or that form en masse in multiciliated cells. Several recent studies have begun to uncover the links between centriole duplication and their transformation to basal bodies.

Light microscopical observation of infraciliary bands of Eodinium posterovesiculatum in comparison with Entodinium bursa and Diplodinium dentatum.

Morphological features of the four morphotypes of the rumen ciliate, Eodinium posterovesiculatum, are described from pyridinated silver carbonate-impregnated specimens. Infraciliary bands are compared with those of Entodinium bursa and Diplodinium dentatum. In Entodinium bursa, the adoral polybrachykinety is "C" shaped and the vestibular polybrachykinety extends from the dorsal extremity of the adoral polybrachykinety as in other Entodinium species. In Diplodinium dentatum, the adoral polybrachykinety encircles most of the circumference of the vestibular opening and the vestibular polybrachykinety extends from the inner side of the adoral polybrachykinety as in other Diplodinium species. Infraciliary bands in Eodinium posterovesiculatum encircle the whole circumference of the vestibular opening and are, therefore, distinct from Entodinium, Diplodinium and other ciliates in the family Ophryoscolecidae. In Eodinium posterovesiculatum, the adoral polybrachykinety and the anterior part of the vestibular polybrachykinety encircle the vestibular opening. The wide and long vestibular polybrachykinety extends along the right wall of the tubular vestibulum and is bordered by a kinety. Kinetids in the central part of the vestibular polybrachykinety are randomly disposed. The genus Eodinium is valid because of this characteristic polybrachykinety arrangement in Eodinium posterovesiculatum.

Laser ablation reveals regulation of ciliary activity by serotonergic neurons in molluscan embryos.

Early in embryonic development, the pond snail Helisoma trivolvis exhibits a rotational behavior that is generated by beating of cilia in the dorsolateral and pedal bands. Although previous anatomical and pharmacological studies provided indirect evidence that a pair of serotonergic neurons, Embryonic Neurons C1 (ENC1s), is involved in regulating embryonic rotation, direct evidence linking ENC1 to ciliary function is still lacking. In the present study, we used laser microbeams to perturb ENC1 in vivo while monitoring ciliary activity in identified ciliary bands. A laser treatment protocol to specifically ablate ENC1 without damaging the surrounding cells was established. Unilateral laser treatment of ENC1 caused transient increases in the activity of the pedal and ipsidorsolateral cilia, lasting 30-50 min. In contrast, activity of cilia that were not anatomically associated with ENC1 was unaffected by laser treatment. Mianserin, an effective serotonin antagonist in Helisoma ciliated cells, decreased the overall CBF of pedal and dorsolateral cilia by reducing the occurrence of spontaneous CBF surges in these cilia. Finally, the cilioexcitatory action of ENC1 laser treatment was mimicked by serotonin and reduced in the presence of mianserin. These results suggest that laser treatment provokes a release of serotonin from ENC1, resulting in a prolonged elevation of activity in the target ciliary cells. We conclude that, in addition to their previously established role in regulating neurodevelopment, ENC1s also function as serotonergic motor neurons to regulate ciliary activity, and therefore the rotational behavior of early embryos.

Changes in morphology and physiology of olfactory receptor cilia during development.

Ciliated olfactory receptor neurons in vertebrates turn over throughout life. We show that these neurons bear different types of cilia at different developmental stages; cilia on newly differentiating cells are short and motile; cilia on mature cells are longer and immotile; Mg2+ and adenosine 5'-triphosphate are requisite for ciliary motion; stimulation with odorants can induce synchronous motion and that this process is mediated by Ca2+. We propose that receptor neurons have two distinguishable developmental states. In the first, before the growing axon establishes synaptic connection to the brain, the cells bear motile cilia and are generally irritable. In the second, the cilia are long and immotile and the cells can distinguish between odorants.