scholarly journals Ectosome uptake by glia sculpts Caenorhabditis elegans sensory cilia

2021 ◽  
Author(s):  
Adrià Razzauti ◽  
Patrick Laurent
Keyword(s):  
Caenorhabditis Elegans ◽  
Cell Surface ◽  
Glial Cells ◽  
Intraflagellar Transport ◽  
Membrane Receptors ◽  
Sensory Function ◽  
C Elegans ◽  
Sensory Cilia

AbstractCilia are sensory organelles protruding from cell surface. A tight regulation of membrane receptors traffic in and out of cilia is achieved by the action of Intraflagellar Transport (IFT). Here, we show that ectosomes bud from a subset of C. elegans sensory cilia. Packing and disposal of ciliary receptors in ectosomes complement their retrieval by IFT. Mutations in ciliary retrieval genes increase export of the salt sensor GCY-22 from ASER neurons by ectosomes, preventing its accumulation in ASER cilia. Ectosomes are produced from two ciliary locations: cilia tip and/or cilia base. Ectosomes budding from cilia tip are released in the environment. Ectosomes produced from the cilia base are concomitantly phagocytosed by the associated glial cells. Although ectocytosis does not require glia to occur, ectosome phagocytosis by the contacting glia contributes to maintain cilia shape and sensory function. We suggest this coordinated neuron-glia interaction is required for proper cilia function.

Intraflagellar transport motors in Caenorhabditis elegans neurons

2004 ◽  
Vol 32 (5) ◽  
pp. 682-684 ◽  
Author(s):  
J.M. Scholey ◽  
G. Ou ◽  
J. Snow ◽  
A. Gunnarson
Keyword(s):  
Caenorhabditis Elegans ◽  
Fluorescent Protein ◽  
Protein Complexes ◽  
Intraflagellar Transport ◽  
Time Lapse ◽  
Protein Fusion ◽  
C Elegans ◽  
Sensory Cilia ◽  
Macromolecular Protein ◽  
Green Fluorescent

IFT (intraflagellar transport) assembles and maintains sensory cilia on the dendritic endings of chemosensory neurons within the nematode Caenorhabditis elegans. During IFT, macromolecular protein complexes called IFT particles (which carry ciliary precursors) are moved from the base of the sensory cilium to its distal tip by anterograde IFT motors (kinesin-II and Osm-3 kinesin) and back to the base by retrograde IFT-dynein [Rosenbaum and Witman (2002) Nat. Rev. Mol. Cell Biol. 3, 813–825; Scholey (2003) Annu. Rev. Cell Dev. Biol. 19, 423–443; and Snell, Pan and Wang (2004) Cell 117, 693–697]. In the present study, we describe the protein machinery of IFT in C. elegans, which we have analysed using time-lapse fluorescence microscopy of green fluorescent protein-fusion proteins in concert with ciliary mutants.

scholarly journals The Caenorhabditis elegans nephrocystins act as global modifiers of cilium structure

2008 ◽  
Vol 180 (5) ◽  
pp. 973-988 ◽  
Author(s):  
Andrew R. Jauregui ◽  
Ken C.Q. Nguyen ◽  
David H. Hall ◽  
Maureen M. Barr
Keyword(s):  
Caenorhabditis Elegans ◽  
Intraflagellar Transport ◽  
Basal Bodies ◽  
Structural Components ◽  
Transition Zones ◽  
C Elegans ◽  
Cell Type Specific ◽  
Children And Young Adults ◽  
Stage Renal Disease ◽  
End Stage

Nephronophthisis (NPHP) is the most common genetic cause of end-stage renal disease in children and young adults. In Chlamydomonas reinhardtii, Caenorhabditis elegans, and mammals, the NPHP1 and NPHP4 gene products nephrocystin-1 and nephrocystin-4 localize to basal bodies or ciliary transition zones (TZs), but their function in this location remains unknown. We show here that loss of C. elegans NPHP-1 and NPHP-4 from TZs is tolerated in developing cilia but causes changes in localization of specific ciliary components and a broad range of subtle axonemal ultrastructural defects. In amphid channel cilia, nphp-4 mutations cause B tubule defects that further disrupt intraflagellar transport (IFT). We propose that NPHP-1 and NPHP-4 act globally at the TZ to regulate ciliary access of the IFT machinery, axonemal structural components, and signaling molecules, and that perturbing this balance results in cell type–specific phenotypes.

scholarly journals Caenorhabditis elegans DYF-2, an Orthologue of Human WDR19, Is a Component of the Intraflagellar Transport Machinery in Sensory Cilia

2006 ◽  
Vol 17 (11) ◽  
pp. 4801-4811 ◽  
Author(s):  
Evgeni Efimenko ◽  
Oliver E. Blacque ◽  
Guangshuo Ou ◽  
Courtney J. Haycraft ◽  
Bradley K. Yoder ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Aspartic Acid ◽  
Critical Role ◽  
Intraflagellar Transport ◽  
Bardet Biedl Syndrome ◽  
Evolutionarily Conserved ◽  
Sensory Cilia ◽  
Mutant Phenotypes ◽  
And Function

The intraflagellar transport (IFT) machinery required to build functional cilia consists of a multisubunit complex whose molecular composition, organization, and function are poorly understood. Here, we describe a novel tryptophan-aspartic acid (WD) repeat (WDR) containing IFT protein from Caenorhabditis elegans, DYF-2, that plays a critical role in maintaining the structural and functional integrity of the IFT machinery. We determined the identity of the dyf-2 gene by transgenic rescue of mutant phenotypes and by sequencing of mutant alleles. Loss of DYF-2 function selectively affects the assembly and motility of different IFT components and leads to defects in cilia structure and chemosensation in the nematode. Based on these observations, and the analysis of DYF-2 movement in a Bardet–Biedl syndrome mutant with partially disrupted IFT particles, we conclude that DYF-2 can associate with IFT particle complex B. At the same time, mutations in dyf-2 can interfere with the function of complex A components, suggesting an important role of this protein in the assembly of the IFT particle as a whole. Importantly, the mouse orthologue of DYF-2, WDR19, also localizes to cilia, pointing to an important evolutionarily conserved role for this WDR protein in cilia development and function.

A cilia-mediated environmental input induces solitary behaviour in Caenorhabditis elegans and Pristionchus pacificus nematodes

Nematology ◽  
2018 ◽  
Vol 20 (3) ◽  
pp. 201-209 ◽  
Author(s):  
Eduardo Moreno ◽  
Ralf J. Sommer
Keyword(s):  
Caenorhabditis Elegans ◽  
Social Behaviour ◽  
Intraflagellar Transport ◽  
Large Protein ◽  
Pristionchus Pacificus ◽  
C Elegans ◽  
The Social ◽  
Genes Encoding ◽  
Social Behaviours ◽  
Ciliated Neurons

Nematodes respond to a multitude of environmental cues. For example, the social behaviours clumping and bordering were described as a mechanism of hyperoxia avoidance in Caenorhabditis elegans and Pristionchus pacificus. A recent study in P. pacificus revealed a novel regulatory pathway that inhibits social behaviour in a response to an as yet unknown environmental cue. This environmental signal is recognised by ciliated neurons, as mutants defective in intraflagellar transport (IFT) proteins display social behaviours. The IFT machinery represents a large protein complex and many mutants in genes encoding IFT proteins are available in C. elegans. However, social phenotypes in C. elegans IFT mutants have never been reported. Here, we examined 15 previously isolated C. elegans IFT mutants and found that most of them showed strong social behaviour. These findings indicate conservation in the inhibitory mechanism of social behaviour between P. pacificus and C. elegans.

scholarly journals Dynein-Driven Retrograde Intraflagellar Transport Is Triphasic in C. elegans Sensory Cilia

2017 ◽  
Vol 27 (10) ◽  
pp. 1448-1461.e7 ◽  
Author(s):  
Peishan Yi ◽  
Wen-Jun Li ◽  
Meng-Qiu Dong ◽  
Guangshuo Ou
Keyword(s):  
Intraflagellar Transport ◽  
C Elegans ◽  
Sensory Cilia

scholarly journals Two anterograde intraflagellar transport motors cooperate to build sensory cilia on C. elegans neurons

2004 ◽  
Vol 6 (11) ◽  
pp. 1109-1113 ◽  
Author(s):  
Joshua J. Snow ◽  
Guangshuo Ou ◽  
Amy L. Gunnarson ◽  
M. Regina S. Walker ◽  
H. Mimi Zhou ◽  
...  
Keyword(s):  
Intraflagellar Transport ◽  
C Elegans ◽  
Sensory Cilia

scholarly journals MAK and CCRK kinases regulate kinesin-2 motility in C. elegans neuronal cilia

2017 ◽  
Author(s):  
Peishan Yi ◽  
Chao Xie ◽  
Guangshuo Ou
Keyword(s):  
Cell Cycle ◽  
Sensory Neurons ◽  
Intraflagellar Transport ◽  
Time Lapse ◽  
Genetic Screen ◽  
Forward Genetic Screen ◽  
C Elegans ◽  
Neuronal Cilia ◽  
Sensory Cilia

AbstractKinesin-2 motors power the anterograde intraflagellar transport (IFT), a highly ordered process that assembles and maintains cilia. It remains elusive how kinesin-2 motors are regulated in vivo. Here we perform forward genetic screen to isolate suppressors that rescue the ciliary defects in the constitutive active mutation of OSM-3-kinesin (G444E) in C. elegans sensory neurons. We identify the C. elegans DYF-5 and DYF-18, which encode the homologs of mammalian male germ cell-associated kinase (MAK) and cell cycle-related kinase (CCRK). Using time-lapse fluorescence microscopy, we show that DYF-5 and DYF-18 are IFT cargo molecules and are enriched at the distal segments of sensory cilia. Mutations of dyf-5 and dyf-18 generate the elongated cilia and ectopic localization of kinesin-II at the ciliary distal segments. Genetic analyses reveal that dyf-5 and dyf-18 are also important for stabilizing the interaction between IFT particle and OSM-3-kinesin. Our data suggest that DYF-5 and DYF-18 act in the same pathway to promote handover between kinesin-II and OSM-3 in sensory cilia.

scholarly journals Functional modulation of IFT kinesins extends the sensory repertoire of ciliated neurons in Caenorhabditis elegans

2006 ◽  
Vol 172 (5) ◽  
pp. 663-669 ◽  
Author(s):  
James E. Evans ◽  
Joshua J. Snow ◽  
Amy L. Gunnarson ◽  
Guangshuo Ou ◽  
Henning Stahlberg ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Intraflagellar Transport ◽  
Full Length ◽  
Sensory Stimuli ◽  
Sensory Cilia ◽  
Section Electron ◽  
Functional Modulation ◽  
Serial Section Electron Microscopy ◽  
Section Electron Microscopy ◽  
Ciliated Neurons

The diversity of sensory cilia on Caenorhabditis elegans neurons allows the animal to detect a variety of sensory stimuli. Sensory cilia are assembled by intraflagellar transport (IFT) kinesins, which transport ciliary precursors, bound to IFT particles, along the ciliary axoneme for incorporation into ciliary structures. Using fluorescence microscopy of living animals and serial section electron microscopy of high pressure–frozen, freeze-substituted IFT motor mutants, we found that two IFT kinesins, homodimeric OSM-3 kinesin and heterotrimeric kinesin II, function in a partially redundant manner to build full-length amphid channel cilia but are completely redundant for building full-length amphid wing (AWC) cilia. This difference reflects cilia-specific differences in OSM-3 activity, which serves to extend distal singlets in channel cilia but not in AWC cilia, which lack such singlets. Moreover, AWC-specific chemotaxis assays reveal novel sensory functions for kinesin II in these wing cilia. We propose that kinesin II is a “canonical” IFT motor, whereas OSM-3 is an “accessory” IFT motor, and that subtle changes in the deployment or actions of these IFT kinesins can contribute to differences in cilia morphology, cilia function, and sensory perception.

scholarly journals The WD Repeat-containing Protein IFTA-1 Is Required for Retrograde Intraflagellar Transport

2006 ◽  
Vol 17 (12) ◽  
pp. 5053-5062 ◽  
Author(s):  
Oliver E. Blacque ◽  
Chunmei Li ◽  
Peter N. Inglis ◽  
Muneer A. Esmail ◽  
Guangshuo Ou ◽  
...  
Keyword(s):  
Protein Complexes ◽  
Intraflagellar Transport ◽  
Retrograde Transport ◽  
Bardet Biedl Syndrome ◽  
C Elegans ◽  
Gene Mutant ◽  
Strong Homology ◽  
Sensory Cilia ◽  
Wd Repeat ◽  
Mammalian Protein

The assembly and maintenance of cilia require intraflagellar transport (IFT), a microtubule-dependent bidirectional motility of multisubunit protein complexes along ciliary axonemes. Defects in IFT and the functions of motile or sensory cilia are associated with numerous human ailments, including polycystic kidney disease and Bardet–Biedl syndrome. Here, we identify a novel Caenorhabditis elegans IFT gene, IFT-associated gene 1 (ifta-1), which encodes a WD repeat-containing protein with strong homology to a mammalian protein of unknown function. Both the C. elegans and human IFTA-1 proteins localize to the base of cilia, and in C. elegans, IFTA-1 can be observed to undergo IFT. IFTA-1 is required for the function and assembly of cilia, because a C. elegans ifta-1 mutant displays chemosensory abnormalities and shortened cilia with prominent ciliary accumulations of core IFT machinery components that are indicative of retrograde transport defects. Analyses of C. elegans IFTA-1 localization/motility along bbs mutant cilia, where anterograde IFT assemblies are destabilized, and in a che-11 IFT gene mutant, demonstrate that IFTA-1 is closely associated with the IFT particle A subcomplex, which is implicated in retrograde IFT. Together, our data indicate that IFTA-1 is a novel IFT protein that is required for retrograde transport along ciliary axonemes.

scholarly journals Caenorhabditis elegans exhibits positive gravitaxis

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Wei-Long Chen ◽  
Hungtang Ko ◽  
Han-Sheng Chuang ◽  
David M. Raizen ◽  
Haim H. Bau
Keyword(s):  
Caenorhabditis Elegans ◽  
Molecular Mechanisms ◽  
Life Forms ◽  
The Body ◽  
C Elegans ◽  
Neural Processes ◽  
Sensory Cilia ◽  
Touch Response ◽  
Vector Direction ◽  
Hydrodynamic Effects

Abstract Background Gravity plays an important role in most life forms on Earth. Yet, a complete molecular understanding of sensing and responding to gravity is lacking. While there are anatomical differences among animals, there is a remarkable conservation across phylogeny at the molecular level. Caenorhabditis elegans is suitable for gene discovery approaches that may help identify molecular mechanisms of gravity sensing. It is unknown whether C. elegans can sense the direction of gravity. Results In aqueous solutions, motile C. elegans nematodes align their swimming direction with the gravity vector direction while immobile worms do not. The worms orient downward regardless of whether they are suspended in a solution less dense (downward sedimentation) or denser (upward sedimentation) than themselves. Gravitaxis is minimally affected by the animals’ gait but requires sensory cilia and dopamine neurotransmission, as well as motility; it does not require genes that function in the body touch response. Conclusions Gravitaxis is not mediated by passive forces such as non-uniform mass distribution or hydrodynamic effects. Rather, it is mediated by active neural processes that involve sensory cilia and dopamine. C. elegans provides a genetically tractable system to study molecular and neural mechanisms of gravity sensing.

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