scholarly journals Caenorhabditis elegans Teneurin, ten-1, Is Required for Gonadal and Pharyngeal Basement Membrane Integrity and Acts Redundantly with Integrin ina-1 and Dystroglycan dgn-1

2008 ◽  
Vol 19 (9) ◽  
pp. 3898-3908 ◽  
Author(s):  
Agnieszka Trzebiatowska ◽  
Ulrike Topf ◽  
Ursula Sauder ◽  
Krzysztof Drabikowski ◽  
Ruth Chiquet-Ehrismann

The Caenorhabditis elegans teneurin ortholog, ten-1, plays an important role in gonad and pharynx development. We found that lack of TEN-1 does not affect germline proliferation but leads to local basement membrane deficiency and early gonad disruption. Teneurin is expressed in the somatic precursor cells of the gonad that appear to be crucial for gonad epithelialization and basement membrane integrity. Ten-1 null mutants also arrest as L1 larvae with malformed pharynges and disorganized pharyngeal basement membranes. The pleiotropic phenotype of ten-1 mutant worms is similar to defects found in basement membrane receptor mutants ina-1 and dgn-1 as well as in the mutants of the extracellular matrix component laminin, epi-1. We show that the ten-1 mutation is synthetic lethal with mutations of genes encoding basement membrane components and receptors due to pharyngeal or hypodermal defects. This indicates that TEN-1 could act redundantly with integrin INA-1, dystroglycan DGN-1, and laminin EPI-1 in C. elegans development. Moreover, ten-1 deletion sensitizes worms to loss of nidogen nid-1 causing a pharynx unattached phenotype in ten-1;nid-1 double mutants. We conclude that TEN-1 is important for basement membrane maintenance and/or adhesion in particular organs and affects the function of somatic gonad precursor cells.

2011 ◽  
Vol 22 (18) ◽  
pp. 3331-3343 ◽  
Author(s):  
Ulrike Topf ◽  
Ruth Chiquet-Ehrismann

Teneurins are a family of phylogenetically conserved proteins implicated in pattern formation and morphogenesis. The sole orthologue in Caenorhabditis elegans, ten-1, is important for hypodermal cell migration, neuronal migration, path finding and fasciculation, gonad development, and basement membrane integrity of some tissues. However, the mechanisms of TEN-1 action remain to be elucidated. Using a genome-wide RNA interference approach, we identified phy-1 as a novel interaction partner of ten-1. phy-1 codes for the catalytic domain of collagen prolyl 4-hydroxylase. Loss of phy-1 significantly enhanced the embryonic lethality of ten-1 null mutants. Double-mutant embryos arrested during late elongation with epidermal defects, disruption of basement membranes, and detachment of body wall muscles. We found that deletion of phy-1 caused aggregation of collagen IV in body wall muscles in elongated embryos and triggered the loss of tissue integrity in ten-1 mutants. In addition, phy-1 and ten-1 each genetically interact with genes encoding collagen IV. These findings support a functional mechanism in which loss of ten-1, together with a reduction of assembled and secreted basement membrane collagen IV protein, leads to detachment of the epidermis from muscle cells during late elongation of the embryo when mechanical stress is generated by muscle contractions.


2018 ◽  
Vol 115 (45) ◽  
pp. 11537-11542 ◽  
Author(s):  
Rodrigo Cáceres ◽  
Nagagireesh Bojanala ◽  
Laura C. Kelley ◽  
Jes Dreier ◽  
John Manzi ◽  
...  

During invasion, cells breach basement membrane (BM) barriers with actin-rich protrusions. It remains unclear, however, whether actin polymerization applies pushing forces to help break through BM, or whether actin filaments play a passive role as scaffolding for targeting invasive machinery. Here, using the developmental event of anchor cell (AC) invasion inCaenorhabditis elegans, we observe that the AC deforms the BM and underlying tissue just before invasion, exerting forces in the tens of nanonewtons range. Deformation is driven by actin polymerization nucleated by the Arp2/3 complex and its activators, whereas formins and cross-linkers are dispensable. Delays in invasion upon actin regulator loss are not caused by defects in AC polarity, trafficking, or secretion, as appropriate markers are correctly localized in the AC even when actin is reduced and invasion is disrupted. Overall force production emerges from this study as one of the main tools that invading cells use to promote BM disruption inC. elegans.


Development ◽  
1991 ◽  
Vol 113 (3) ◽  
pp. 797-803 ◽  
Author(s):  
M.J. Stern ◽  
H.R. Horvitz

In wild-type Caenorhabditis elegans hermaphrodites, two bilaterally symmetric sex myoblasts (SMs) migrate anteriorly to flank the precise center of the gonad, where they divide to generate the muscles required for egg laying (J. E. Sulston and H. R. Horvitz (1977) Devl Biol. 56, 110–156). Although this migration is largely independent of the gonad, a signal from the gonad attracts the SMs to their precise final positions (J. H. Thomas, M. J. Stern and H. R. Horvitz (1990) Cell 62, 1041–1052). Here we show that mutations in either of two genes, egl-15 and egl-17, cause the premature termination of the migrations of the SMs. This incomplete migration is caused by the repulsion of the SMs by the same cells in the somatic gonad that are the source of the attractive signal in wild-type animals.


Development ◽  
1985 ◽  
Vol 89 (1) ◽  
pp. 243-257
Author(s):  
Koji Kimata ◽  
Teruyo Sakakura ◽  
Yutaka Inaguma ◽  
Masato Kato ◽  
Yasuaki Nishizuka

Two different types of mesenchyme, fat pad precursor cells (FP) and fibroblastic cells (MM) are involved in the morphogenesis of mammary gland epithelium of mouse embryo. Especially, an interaction between FP and the epithelium is necessary for its characteristic shaping of ductal branching structure. To assess the relative participations of the mesenchymes, we have analysed the extracellular matrix products by immunofluorescent staining method using antibodies to laminin, proteoheparan sulphate, and fibronectin. The staining patterns suggested that, after the 16th day of gestation when fatty substances first appeared in FP and the epithelial rudiments started to elongate and branch rapidly, FP initiated synthesis of laminin and proteoheparan sulphate, while MM synthesized fibronectin at all times. Attention was also paid to differences in the epithelial basement membranes (BM) concomitant with ones in the mesenchyme. BM were always stained with antibodies to laminin and proteoheparan sulphate. However, topographical differences in thickness were observed: the one facing FP, often seen at the tip region of the end bud, was thin, while the other surrounded by MM, often at the flank region of the duct, was thick. Specific elaboration of BM-like extracellular matrix products by FP may attribute to observed differences in BM thickness which are related to the characteristic shaping of the mammary gland.


Genetics ◽  
2020 ◽  
Vol 214 (4) ◽  
pp. 869-893 ◽  
Author(s):  
Tatsuya Tsukamoto ◽  
Micah D. Gearhart ◽  
Seongseop Kim ◽  
Gemechu Mekonnen ◽  
Caroline A. Spike ◽  
...  

Mutations affecting spliceosomal proteins are frequently found in hematological malignancies, including myelodysplastic syndromes and acute myeloid leukemia (AML). DDX41/Abstrakt is a metazoan-specific spliceosomal DEAD-box RNA helicase that is recurrently mutated in inherited myelodysplastic syndromes and in relapsing cases of AML. The genetic properties and genomic impacts of disease-causing missense mutations in DDX41 and other spliceosomal proteins have been uncertain. Here, we conduct a comprehensive analysis of the Caenorhabditis elegans DDX41 ortholog, SACY-1. Biochemical analyses defined SACY-1 as a component of the C. elegans spliceosome, and genetic analyses revealed synthetic lethal interactions with spliceosomal components. We used the auxin-inducible degradation system to analyze the consequence of SACY-1 depletion on the transcriptome using RNA sequencing. SACY-1 depletion impacts the transcriptome through splicing-dependent and splicing-independent mechanisms. Altered 3′ splice site usage represents the predominant splicing defect observed upon SACY-1 depletion, consistent with a role for SACY-1 in the second step of splicing. Missplicing events appear more prevalent in the soma than the germline, suggesting that surveillance mechanisms protect the germline from aberrant splicing. The transcriptome changes observed after SACY-1 depletion suggest that disruption of the spliceosome induces a stress response, which could contribute to the cellular phenotypes conferred by sacy-1 mutant alleles. Multiple sacy-1/ddx41 missense mutations, including the R525H human oncogenic variant, confer antimorphic activity, suggesting that their incorporation into the spliceosome is detrimental. Antagonistic variants that perturb the function of the spliceosome may be relevant to the disease-causing mutations, including DDX41, affecting highly conserved components of the spliceosome in humans.


Nematology ◽  
2000 ◽  
Vol 2 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Marie Delattre ◽  
Marie-Laure Dichtel ◽  
Marie-Anne Félix

AbstractIn order to study the evolution of nematode vulva development, we focus on Oscheius/Dolichorhabditis sp. CEW1 (Rhabditidae) in comparison with Caenorhabditis elegans. In this species, the fates of the vulval precursor cells are determined by two successive nested inductions by the uterine anchor cell (instead of a single one in C. elegans). This hermaphroditic species can be cultured and handled like C. elegans. We review vulva development in this species. We present some molecular tools and the sequence of the Ras gene. This species is amenable to genetic analysis and we discuss the isolation of morphological markers. Afin d’étudier l’évolution du développement de la vulve des nématodes, nous nous concentrons sur l’espèce Oscheius/Dolichorhabditis sp. CEW1 (Rhabditidae) en la comparant à Caenorhabditis elegans. Dans cette espèce, les destinées des cellules précurseurs de la vulve sont déterminées par deux inductions emboîtées provenant de la cellule ancre de l’utérus (au lieu d’une seule chez C. elegans). Cette espèce hermaphrodite peut être élévée et manipulée comme C. elegans. Nous décrivons le développement de la vulve dans cette espèce. Nous présentons des outils moléculaires et la séquence du gène Ras. Les analyses génétiques sont possibles dans cette espèce et nous discutons l’isolement de marqueurs morphologiques.


2010 ◽  
Vol 432 (3) ◽  
pp. 505-516 ◽  
Author(s):  
Steven T. Laing ◽  
Al Ivens ◽  
Roz Laing ◽  
Sai Ravikumar ◽  
Victoria Butler ◽  
...  

Knowledge of how anthelmintics are metabolized and excreted in nematodes is an integral part of understanding the factors that determine their potency, spectrum of activity and for investigating mechanisms of resistance. Although there is remarkably little information on these processes in nematodes, it is often suggested that they are of minimal importance for the major anthelmintic drugs. Consequently, we have investigated how the model nematode Caenorhabditis elegans responds to and metabolizes albendazole, one of the most important anthelmintic drugs for human and animal use. Using a mutant strain lacking the β-tubulin drug target to minimize generalized stress responses, we show that the transcriptional response is dominated by genes encoding XMEs (xenobiotic-metabolizing enzymes), particularly cytochrome P450s and UGTs (UDP-glucuronosyl transferases). The most highly induced genes are predominantly expressed in the worm intestine, supporting their role in drug metabolism. HPLC-MS/MS revealed the production of two novel glucoside metabolites in C. elegans identifying a major difference in the biotransformation of this drug between nematodes and mammals. This is the first demonstration of metabolism of a therapeutic anthelmintic in C. elegans and provides a framework for its use to functionally investigate nematode anthelmintic metabolism.


2001 ◽  
Vol 152 (6) ◽  
pp. 1219-1232 ◽  
Author(s):  
Brian D. Ackley ◽  
Jennifer R. Crew ◽  
Harri Elamaa ◽  
Tania Pihlajaniemi ◽  
Calvin J. Kuo ◽  
...  

Type XVIII collagen is a homotrimeric basement membrane molecule of unknown function, whose COOH-terminal NC1 domain contains endostatin (ES), a potent antiangiogenic agent. The Caenorhabditis elegans collagen XVIII homologue, cle-1, encodes three developmentally regulated protein isoforms expressed predominantly in neurons. The CLE-1 protein is found in low amounts in all basement membranes but accumulates at high levels in the nervous system. Deletion of the cle-1 NC1 domain results in viable fertile animals that display multiple cell migration and axon guidance defects. Particular defects can be rescued by ectopic expression of the NC1 domain, which is shown to be capable of forming trimers. In contrast, expression of monomeric ES does not rescue but dominantly causes cell and axon migration defects that phenocopy the NC1 deletion, suggesting that ES inhibits the promigratory activity of the NC1 domain. These results indicate that the cle-1 NC1/ES domain regulates cell and axon migrations in C. elegans.


Nematology ◽  
2018 ◽  
Vol 20 (3) ◽  
pp. 201-209 ◽  
Author(s):  
Eduardo Moreno ◽  
Ralf J. Sommer

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.


2015 ◽  
Vol 5 (3) ◽  
pp. 353-359 ◽  
Author(s):  
Yunting Chen ◽  
Iva Greenwald

Abstract Notch is a receptor that mediates cell–cell interactions that specify binary cell fate decisions in development and tissue homeostasis. Inappropriate Notch signaling is associated with cancer, and mutations in Notch pathway components have been associated with developmental diseases and syndromes. In Caenorhabditis elegans, suppressors of phenotypes associated with constitutively active LIN-12/Notch have identified many conserved core components and direct or indirect modulators. Here, we molecularly identify sel(ar584), originally isolated as a suppressor of a constitutively active allele of lin-12. We show that sel(ar584) is an allele of hecd-1, the ortholog of human HECDT1, a ubiquitin ligase that has been implicated in several different mammalian developmental events. We studied interactions of hecd-1 with lin-12 in the somatic gonad and with the other C. elegans Notch gene, glp-1, in the germ line. We found that hecd-1 acts as a positive modulator of lin-12/Notch activity in a somatic gonad context—the original basis for its isolation—but acts autonomously as a negative modulator of glp-1/Notch activity in the germ line. As the yeast ortholog of HECD-1, Ufd4p, has been shown to function in quality control, and C. elegans  HECD-1 has been shown to affect mitochondrial maintenance, we propose that the different genetic interactions between hecd-1 and Notch genes we observed in different cell contexts may reflect differences in quality control regulatory mechanisms or in cellular metabolism.


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