scholarly journals Morphogenesis of neurons and glia within an epithelium

2018 ◽  
Author(s):  
Isabel I. C. Low ◽  
Claire R. Williams ◽  
Megan K. Chong ◽  
Ian G. McLachlan ◽  
Bradley M. Wierbowski ◽  
...  
Keyword(s):  
Tight Junctions ◽  
Epithelial Integrity ◽  
C Elegans ◽  
Epithelial Tubes

ABSTRACTTo sense the outside world, some neurons protrude across epithelia, the cellular barriers that line every surface of our bodies. To study the morphogenesis of such neurons, we examined the C. elegans amphid, in which dendrites protrude through a glial channel at the nose. During development, amphid dendrites extend by attaching to the nose via DYF-7, a type of protein typically found in epithelial apical ECM. Here, we show that amphid neurons and glia exhibit epithelial properties, including tight junctions and apical-basal polarity, and develop in a manner resembling other epithelia. We find that DYF-7 is a fibril-forming apical ECM component that prevents rupture of the tube-shaped glial channel, reminiscent of roles for apical ECM in other narrow epithelial tubes. We also identify a role for FRM-2, a homolog of EPBL15/moe/Yurt which promote epithelial integrity in other systems. Finally, we show that other environmentally-exposed neurons share a requirement for DYF-7. Together, our results suggest that these neurons and glia can be viewed as part of an epithelium continuous with the skin, and are shaped by mechanisms shared with other epithelia.

scholarly journals Integrity of Narrow Epithelial Tubes in the C. elegans Excretory System Requires a Transient Luminal Matrix

PLoS Genetics ◽  
2016 ◽  
Vol 12 (8) ◽  
pp. e1006205 ◽  
Author(s):  
Hasreet K. Gill ◽  
Jennifer D. Cohen ◽  
Jesus Ayala-Figueroa ◽  
Rachel Forman-Rubinsky ◽  
Corey Poggioli ◽  
...  
Keyword(s):  
Excretory System ◽  
C Elegans ◽  
Epithelial Tubes

scholarly journals Cell Interactions and Patterned Intercalations Shape and Link Epithelial Tubes in C. elegans

PLoS Genetics ◽  
2013 ◽  
Vol 9 (9) ◽  
pp. e1003772 ◽  
Author(s):  
Jeffrey P. Rasmussen ◽  
Jessica L. Feldman ◽  
Sowmya Somashekar Reddy ◽  
James R. Priess
Keyword(s):  
Cell Interactions ◽  
C Elegans ◽  
Epithelial Tubes

scholarly journals Requirement of the Caenorhabditis elegans RapGEF pxf-1 and rap-1 for Epithelial Integrity

2005 ◽  
Vol 16 (1) ◽  
pp. 106-116 ◽  
Author(s):  
W. Pellis-van Berkel ◽  
M.H.G. Verheijen ◽  
E. Cuppen ◽  
M. Asahina ◽  
J. de Rooij ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Fluorescent Protein ◽  
Catalytic Domain ◽  
Nucleotide Exchange ◽  
Epithelial Integrity ◽  
C Elegans ◽  
Cellular Processes ◽  
Guanine Nucleotide Exchange ◽  
Polarized Secretion ◽  
Green Fluorescent

The Rap-pathway has been implicated in various cellular processes but its exact physiological function remains poorly defined. Here we show that the Caenorhabditis elegans homologue of the mammalian guanine nucleotide exchange factors PDZ-GEFs, PXF-1, specifically activates Rap1 and Rap2. Green fluorescent protein (GFP) reporter constructs demonstrate that sites of pxf-1 expression include the hypodermis and gut. Particularly striking is the oscillating expression of pxf-1 in the pharynx during the four larval molts. Deletion of the catalytic domain from pxf-1 leads to hypodermal defects, resulting in lethality. The cuticle secreted by pxf-1 mutants is disorganized and can often not be shed during molting. At later stages, hypodermal degeneration is seen and animals that reach adulthood frequently die with a burst vulva phenotype. Importantly, disruption of rap-1 leads to a similar, but less severe phenotype, which is enhanced by the simultaneous removal of rap-2. In addition, the lethal phenotype of pxf-1 can be rescued by expression of an activated version of rap-1. Together these results demonstrate that the pxf-1/rap pathway in C. elegans is required for maintenance of epithelial integrity, in which it probably functions in polarized secretion.

Unexpected Roles of the Na-K-ATPase and Other Ion Transporters in Cell Junctions and Tubulogenesis

Physiology ◽  
2009 ◽  
Vol 24 (3) ◽  
pp. 192-201 ◽  
Author(s):  
Thomas Krupinski ◽  
Greg J. Beitel
Keyword(s):  
Ion Transport ◽  
Intercellular Junctions ◽  
Cell Junctions ◽  
Ion Pumps ◽  
Ion Transporters ◽  
C Elegans ◽  
Independent Functions ◽  
Junctional Complexes ◽  
And Control ◽  
Epithelial Tubes

Recent work shows that transport-independent as well as transport-dependent functions of ion transporters, and in particular the Na-K-ATPase, are required for formation and maintenance of several intercellular junctions. Furthermore, these junctional and other nonjunctional functions of ion transporters contribute to development of epithelial tubes. Here, we consider what has been learned about the roles of ion pumps in formation of junctions and epithelial tubes in mammals, zebrafish, Drosophila, and C. elegans. We propose that asymmetric association of the Na-K-ATPase with cell junctions early in metazoan evolution enabled vectorial transcellular ion transport and control of intraorganismal environment. Ion transport-independent functions of the Na-K-ATPase arose as junctional complexes evolved.

Involvement of ASIP/PAR-3 in the promotion of epithelial tight junction formation

2002 ◽  
Vol 115 (12) ◽  
pp. 2485-2495 ◽  
Author(s):  
Tomonori Hirose ◽  
Yasushi Izumi ◽  
Yoji Nagashima ◽  
Yoko Tamai-Nagai ◽  
Hidetake Kurihara ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Tight Junction ◽  
Tight Junctions ◽  
Mdck Cells ◽  
C Elegans ◽  
Tight Junction Formation ◽  
Junction Formation ◽  
Epithelial Tight Junction ◽  
Binding Sequence ◽  
Cell Cell

The mammalian protein ASIP/PAR-3 interacts with atypical protein kinase C isotypes (aPKC) and shows overall sequence similarity to the invertebrate proteins C. elegans PAR-3 and Drosophila Bazooka, which are crucial for the establishment of polarity in various cells. The physical interaction between ASIP/PAR-3 and aPKC is also conserved in C. elegans PAR-3 and PKC-3 and in Drosophila Bazooka and DaPKC. In mammals, ASIP/PAR-3 colocalizes with aPKC and concentrates at the tight junctions of epithelial cells, but the biological meaning of ASIP/PAR-3 in tight junctions remains to be clarified. In the present study, we show that ASIP/PAR-3 staining distributes to the subapical domain of epithelial cell-cell junctions, including epithelial cells with less-developed tight junctions, in clear contrast with ZO-1, another tight-junction-associated protein, the staining of which is stronger in cells with well-developed tight junctions. Consistently, immunogold electron microscopy revealed that ASIP/PAR-3 concentrates at the apical edge of tight junctions, whereas ZO-1 distributes alongside tight junctions. To clarify the meaning of this characteristic localization of ASIP, we analyzed the effects of overexpressed ASIP/PAR-3 on tight junction formation in cultured epithelial MDCK cells. The induced overexpression of ASIP/PAR-3, but not its deletion mutant lacking the aPKC-binding sequence, promotes cell-cell contact-induced tight junction formation in MDCK cells when evaluated on the basis of transepithelial electrical resistance and occludin insolubilization. The significance of the aPKC-binding sequence in tight junction formation is also supported by the finding that the conserved PKC-phosphorylation site within this sequence,ASIP-Ser827, is phosphorylated at the most apical tip of cell-cell contacts during the initial phase of tight junction formation in MDCK cells. Together,our present data suggest that ASIP/PAR-3 regulates epithelial tight junction formation positively through interaction with aPKC.

scholarly journals RAB11A-mediated YAP localization to adherens and tight junctions is essential for colonic epithelial integrity

2021 ◽  
pp. 100848
Author(s):  
Sayantani Goswami ◽  
Iyshwarya Balasubramanian ◽  
Luca D’Agostino ◽  
Sheila Bandyopadhyay ◽  
Radha Patel ◽  
...  
Keyword(s):  
Tight Junctions ◽  
Epithelial Integrity

Freeze-etch observations on the tight junctions of sertoli cells grown in organ culture with FSH

1978 ◽  
Vol 36 (2) ◽  
pp. 340-341
Author(s):  
Rita Meyer ◽  
Zoltan Posalaky ◽  
Dennis Mcginley
Keyword(s):  
Organ Culture ◽  
Tight Junctions ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Barrier Function ◽  
Cell Junction ◽  
Intramembranous Particles ◽  
Junctional Complexes ◽  
Oriented Parallel

The Sertoli cell tight junctional complexes have been shown to be the most important structural counterpart of the physiological blood-testis barrier. In freeze etch replicas they consist of extensive rows of intramembranous particles which are not only oriented parallel to one another, but to the myoid layer as well. Thus the occluding complex has both an internal and an overall orientation. However, this overall orientation to the myoid layer does not seem to be necessary to its barrier function. The 20 day old rat has extensive parallel tight junctions which are not oriented with respect to the myoid layer, and yet they are inpenetrable by lanthanum. The mechanism(s) for the control of Sertoli cell junction development and orientation has not been established, although such factors as the presence or absence of germ cells, and/or hormones, especially FSH have been implicated.

The glycomes of Caenorhabditis elegans and other model organisms

2002 ◽  
Vol 69 ◽  
pp. 117-134 ◽  
Author(s):  
Stuart M. Haslam ◽  
David Gems ◽  
Howard R. Morris ◽  
Anne Dell
Keyword(s):  
Caenorhabditis Elegans ◽  
Current Knowledge ◽  
Structural Data ◽  
Model Organisms ◽  
Entire Genome ◽  
C Elegans ◽  
The Face ◽  
Area Of Concern ◽  
Nematode Worm

There is no doubt that the immense amount of information that is being generated by the initial sequencing and secondary interrogation of various genomes will change the face of glycobiological research. However, a major area of concern is that detailed structural knowledge of the ultimate products of genes that are identified as being involved in glycoconjugate biosynthesis is still limited. This is illustrated clearly by the nematode worm Caenorhabditis elegans, which was the first multicellular organism to have its entire genome sequenced. To date, only limited structural data on the glycosylated molecules of this organism have been reported. Our laboratory is addressing this problem by performing detailed MS structural characterization of the N-linked glycans of C. elegans; high-mannose structures dominate, with only minor amounts of complex-type structures. Novel, highly fucosylated truncated structures are also present which are difucosylated on the proximal N-acetylglucosamine of the chitobiose core as well as containing unusual Fucα1–2Gal1–2Man as peripheral structures. The implications of these results in terms of the identification of ligands for genomically predicted lectins and potential glycosyltransferases are discussed in this chapter. Current knowledge on the glycomes of other model organisms such as Dictyostelium discoideum, Saccharomyces cerevisiae and Drosophila melanogaster is also discussed briefly.

How do histone modifications contribute to transgenerational epigenetic inheritance in C. elegans?

2020 ◽  
Vol 48 (3) ◽  
pp. 1019-1034 ◽  
Author(s):  
Rachel M. Woodhouse ◽  
Alyson Ashe
Keyword(s):  
Histone Modifications ◽  
Molecular Mechanisms ◽  
Epigenetic Inheritance ◽  
Nematode Caenorhabditis Elegans ◽  
Histone Methyltransferases ◽  
Transgenerational Epigenetic Inheritance ◽  
C Elegans ◽  
Recent Developments ◽  
Gene Regulatory

Gene regulatory information can be inherited between generations in a phenomenon termed transgenerational epigenetic inheritance (TEI). While examples of TEI in many animals accumulate, the nematode Caenorhabditis elegans has proven particularly useful in investigating the underlying molecular mechanisms of this phenomenon. In C. elegans and other animals, the modification of histone proteins has emerged as a potential carrier and effector of transgenerational epigenetic information. In this review, we explore the contribution of histone modifications to TEI in C. elegans. We describe the role of repressive histone marks, histone methyltransferases, and associated chromatin factors in heritable gene silencing, and discuss recent developments and unanswered questions in how these factors integrate with other known TEI mechanisms. We also review the transgenerational effects of the manipulation of histone modifications on germline health and longevity.

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