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BMC Biol,
2012]
The dramatic ingression of tissue sheets that accompanies many morphogenetic processes, most notably gastrulation, has been largely attributed to contractile circum-apical actomyosin 'purse-strings' in the infolding cells. Recent studies, however, including one in BMC Biology, expose mechanisms that rely less on actomyosin contractility of purse-string bundles and more on dynamics in the global cortical actomyosin network of the cells. These studies illustrate how punctuated actomyosin contractions and flow of these networks can remodel both epithelial and planarly organized mesenchymal sheets.
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Nat Cell Biol,
2011]
A potential role for glycosphingolipids and lipid rafts in apical sorting was initially met with enthusiasm, but genetic analysis has since provided little support for it. A report now establishes that glycosphingolipids mediate apical sorting, and specifically help maintain apicobasal polarity in Caenorhabditis elegans.
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Curr Biol,
2012]
What are the earliest signals produced at a wound edge that mobilise epithelial cells to heal the wound? Live analysis of wound healing in the worm Caenorhabditis elegans shows that calcium may be the key early trigger.
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Neuron,
2011]
Degenerin/epithelial sodium channels (DEG/ENaCs) are luminaries of gentle touch in Caenorhabditis elegans. In this issue of Neuron, Geffeney etal. demonstrate that eponymous DEG-1 channels carry mechanotransduction currents in a polymodal neuron, where they act upstream of transient receptor potential (TRP) channels.
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Genes Dev,
2008]
Semaphorins play diverse roles in axon guidance and epithelial morphogenetic cell movements. In this issue of Genes & Development, Nukazuka and colleagues (1025-1036) show that semaphorins regulate Caenorhabditis elegans male tail morphogenesis by stimulating the translation of specific messages, including the actin-depolymerizing enzyme cofilin.
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Dev Cell,
2015]
Adherens junctions (AJs) play a crucial role in epithelial tissue development and tumorigenesis, and the mechanisms controlling their assembly and disassembly have therefore attracted considerable attention. A paper from Tsur et al. (2015) in this issue of Developmental Cell now shows how sumoylation and desumoylation of E-cadherin promotes its recruitment to AJs.
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Cell Host Microbe,
2012]
The mechanisms by which epithelial cells distinguish pathogens from commensal microbes have long puzzled us. Now, McEwan etal. (2012) and Dunbar etal. (2012), in this issue of Cell Host & Microbe, demonstrate that inC.elegans, microbial toxin-induced inhibition of host cellular functions, especially blockade ofprotein translation, activates the effector-triggered immune response dependent on the transcription factor ZIP-2.
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Dev Cell,
2003]
In multicellular organisms, most cells are confined to a particular tissue. However, some cells invade organs during normal development and in diseases (e.g., angiogenesis and cancer). Recent studies reveal a fascinating step-by-step process in which specific vulval cells induce and attract a single gonadal cell to invade an epithelial tubular organ in order to connect the uterus to the vulva in C. elegans.
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Nat Cell Biol,
2004]
Why are proteins glycosylated? On the basis of new studies, I propose two models to clarify the specific functions of glycosylation in worms. The first explains how intra- and inter-cellular trafficking of an N-glycosylated disintegrin-metalloprotease guides somatic gonadal cells through their migratory route, determining the shape of an organ. The second explains how rigid coats of secreted chondroitin proteoglycans bend membranes to drive cytokinesis and epithelial invagination.
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J Cell Sci,
2004]
Caenorhabditis elegans is a powerful model system for investigating the establishment, regulation and function of adhesive structures in vivo. C elegans has several adhesion complexes related to those in vertebrates. These include: (1) epithelial apical junctions, which have features of both adherens and tight junctions; (2) dense bodies, which are muscle-attachment structures similar to focal adhesions; (3) fibrous organelles, which resemble hemidesmosomes and mediate mechanical coupling between tissues; and (4) a putative dystrophin-glycoprotein complex that has potential roles in muscle function and embryogenesis. Recent work has increased our understanding of these structures and has given new insights into the functions of their vertebrate counterparts.