Jianghua Yin et al. (2007) International Worm Meeting "Regualtion and function of a sma-9 target gene."

Jianghua Yin, Cathy SavageDunn, Ling Yu

[International Worm Meeting, 2007]

BMP/TGF<font face=symbol>b</font> signaling cascades regulate many aspects of development and differentiation in both vertebrates and invertebrates. In the well-characterized Drosophila Dpp signaling cascade, upon Dpp ligand binding, type I receptor phosphorylates the intracellular signal transducer Mad (R-Smads), which then forms a complex with the Co-Smad Medea (Med). The Smad protein complex will translocate into the nucleus, recruiting transcription cofactor Schnurri (Shn) and inhibiting the brinker gene transcription, which in turn negatively regulates the expression of most Dpp target genes. In Caenorhabditis elegans, the Schnurri homolog SMA-9 is also found to function as a transcription cofactor in the DBL-1 pathway, a BMP/TGF<font face=symbol>b</font>-related signaling cascade, regulating body size and male tail development. The molecular mechanisms of SMA-9 function are still unknown. Study of the sma-9 target genes will help us to illustrate the conserved role of Schnurri/SMA-9 protein function in invertebrates. The T27F2.4 gene, a bZip transcription factor, is found to be highly upregulated in sma-9 mutant background, according to the microarray analysis and real-time PCR data. Meanwhile, RNAi experiment show that in vivo, knockdown of T27F2.4 gene will cause long body size phenotype. Recently, we found that the downstream region of this gene contains a putative silencer element (SE) that is essential for mediating the Dpp-dependent repression of brinker gene transcription in Drosophila via the Shn/Mad/Med complex. This SE also functions similarly in vertebrates. We hypothesize that the regulation of T27F2.4 gene expression and tissue specificity are also mediated through this conserved mechanism. Now we are using GFP reporter constructs containing the SE element to test our hypothesis. Meanwhile, examining how T27F2.4 gene functions in body size development is another goal of our studies.

Barral JM et al. (2002) Science "Role of the myosin assembly protein UNC-45 as a molecular chaperone for myosin."

Barral JM, Hutagalung AH, Epstein HF, Brinker A, Hartl FU

[Science, 2002]

The organization of myosin into motile cellular structures requires precise temporal and spatial regulation. Proteins containing a UCS (UNC-45/CRO1/She4p) domain are necessary for the incorporation of myosin into the contractite ring during cytokinesis and into thick filaments during muscle development. We report that the carboxyl-terminal regions of UNC-45 bound and exerted chaperone activity on the myosin head. The amino-terminal tetratricopeptide repeat domain of UNC-45 bound the molecular chaperone Hsp90. Thus, UNC-45 functions both as a molecular chaperone and as an Hsp90 co-chaperone for myosin, which can explain previous findings of altered assembly and decreased accumulation of myosin in UNC-45 mutants of Caenorhabditis elegans.

Quartey MO et al. (2021) Sci Rep "The A(1-38) peptide is a negative regulator of the A(1-42) peptide implicated in Alzheimer disease progression."

Pennington PR, Quartey MO, Nyarko JNK, Parsons MP, Maley JM, Heistad RM, Leary SC, Barnes JR, Knudsen KJ, De Carvalho CE, Bolanos MAC, Buttigieg J, Mousseau DD

[Sci Rep, 2021]

The pool of -Amyloid (A) length variants detected in preclinical and clinical Alzheimer disease (AD) samples suggests a diversity of roles for A peptides. We examined how a naturally occurring variant, e.g. A(1-38), interacts with the AD-related variant, A(1-42), and the predominant physiological variant, A(1-40). Atomic force microscopy, Thioflavin T fluorescence, circular dichroism, dynamic light scattering, and surface plasmon resonance reveal that A(1-38) interacts differently with A(1-40) and A(1-42) and, in general, A(1-38) interferes with the conversion of A(1-42) to a -sheet-rich aggregate. Functionally, A(1-38) reverses the negative impact of A(1-42) on long-term potentiation in acute hippocampal slices and on membrane conductance in primary neurons, and mitigates an A(1-42) phenotype in Caenorhabditis elegans. A(1-38) also reverses any loss of MTT conversion induced by A(1-40) and A(1-42) in HT-22 hippocampal neurons and APOE 4-positive human fibroblasts, although the combination of A(1-38) and A(1-42) inhibits MTT conversion in APOE 4-negative fibroblasts. A greater ratio of soluble A(1-42)/A(1-38) [and A(1-42)/A(1-40)] in autopsied brain extracts correlates with an earlier age-at-death in males (but not females) with a diagnosis of AD. These results suggest that A(1-38) is capable of physically counteracting, potentially in a sex-dependent manner, the neuropathological effects of the AD-relevant A(1-42).

Danielle Thierry-Mieg et al. (2003) Worm Breeder's Gazette "www.wormgenes.org , a new gene centered database"

Vahan Simonyan, Mark Sienkiewicz, Yuji KOHARA, Michel Potdevin, Tadasu SHIN-I, Jean Thierry-Mieg, Danielle Thierry-Mieg

[Worm Breeder's Gazette, 2003]

Wormgenes is a new resource for C.elegans offering a detailed summary about each gene and a powerful query system.

Hodgkin JA (1998) International Journal of Developmental Biology "Seven types of pleiotropy."

Hodgkin JA

[International Journal of Developmental Biology, 1998]

Pleiotropy , a situation in which a single gene influences multiple phenotypic tra its, can arise in a variety of ways. This paper discusses possible underlying mechanisms and proposes a classification of the various phenomena involved.

Tangrodchanapong T et al. (2020) Front Pharmacol "Frondoside A Attenuates Amyloid- Proteotoxicity in Transgenic Caenorhabditis elegans by Suppressing Its Formation."

Tangrodchanapong T, Sobhon P, Meemon K

[Front Pharmacol, 2020]

Oligomeric assembly of Amyloid- (A) is the main toxic species that contribute to early cognitive impairment in Alzheimer's patients. Therefore, drugs that reduce the formation of A oligomers could halt the disease progression. In this study, by using transgenic <i>Caenorhabditis elegans</i> model of Alzheimer's disease, we investigated the effects of frondoside A, a well-known sea cucumber <i>Cucumaria frondosa</i> saponin with anti-cancer activity, on A aggregation and proteotoxicity. The results showed that frondoside A at a low concentration of 1 M significantly delayed the worm paralysis caused by A aggregation as compared with control group. In addition, the number of A plaque deposits in transgenic worm tissues was significantly decreased. Frondoside A was more effective in these activities than ginsenoside-Rg3, a comparable ginseng saponin. Immunoblot analysis revealed that the level of small oligomers as well as various high molecular weights of A species in the transgenic <i>C. elegans</i> were significantly reduced upon treatment with frondoside A, whereas the level of A monomers was not altered. This suggested that frondoside A may primarily reduce the level of small oligomeric forms, the most toxic species of A. Frondoside A also protected the worms from oxidative stress and rescued chemotaxis dysfunction in a transgenic strain whose neurons express A. Taken together, these data suggested that low dose of frondoside A could protect against A-induced toxicity by primarily suppressing the formation of A oligomers. Thus, the molecular mechanism of how frondoside A exerts its anti-A aggregation should be studied and elucidated in the future.

Tuck S (2011) Curr Biol "Extracellular vesicles: budding regulated by a phosphatidylethanolamine translocase."

Tuck S

[Curr Biol, 2011]

Recent work on a Caenorhabditis elegans transmembrane ATPase reveals a central role for the aminophospholipid phosphatidylethanolamine in the production of a class of extracellular vesicles.

Viney ME et al. (2004) Naturwissenschaften "Is dauer pheromone of Caenorhabditis elegans really a pheromone?"

Viney ME, Franks NR

[Naturwissenschaften, 2004]

Animals respond to signals and cues in their environment. The difference between a signal (e.g. a pheromone) and a cue (e.g. a waste product) is that the information content of a signal is subject to natural selection, whereas that of a cue is not. The model free-living nematode Caenorhabditis elegans forms an alternative developmental morph (the dauer larva) in response to a so-called 'dauer pheromone', produced by all worms. We suggest that the production of 'dauer pheromone' has no fitness advantage for an individual worm and therefore we propose that 'dauer pheromone' is not a signal, but a cue. Thus, it should not be called a pheromone.

Desta IT et al. (2016) J Lab Autom "Detecting and Trapping of a Single C. elegans Worm in a Microfluidic Chip for Automated Microplate Dispensing."

Mustafa N, Orozaliev A, AlGharibeh N, Song YA, Giakoumidis N, Desta IT, Gunsalus KC, Al-Sharif A

[J Lab Autom, 2016]

Microfluidic devices offer new technical possibilities for a precise manipulation of Caenorhabditis elegans due to the comparable length scale. C. elegans is a small, free-living nematode worm that is a popular model system for genetic, genomic, and high-throughput experimental studies of animal development and neurobiology. In this paper, we demonstrate a microfluidic system in polydimethylsiloxane (PDMS) for dispensing of a single C. elegans worm into a 96-well plate. It consists of two PDMS layers, a flow and a control layer. Using five microfluidic pneumatic valves in the control layer, a single worm is trapped upon optical detection with a pair of optical fibers integrated perpendicular to the constriction channel and then dispensed into a microplate well with a dispensing tip attached to a robotic handling system. Due to its simple design and facile fabrication, we expect that our microfluidic chip can be expanded to a multiplexed dispensation system of C. elegans worms for high-throughput drug screening.

Schaeffer JM et al. (1990) J Antibiot (Tokyo) "Cochlioquinone A, a nematocidal agent which competes for specific [3H]ivermectin binding sites."

Frazier EG, Schaeffer JM, Bergstrom AR, Williamson JM, Liesch JM, Goetz MA

[J Antibiot (Tokyo), 1990]

Cochlioquinone A, isolated from the fungus Helminthosporium sativum, was found to have nematocidal activity. Cochlioquinone A is a competitive inhibitor of specific [3H]ivermectin binding suggesting that cochlioquinone A and ivermectin interact with the same membrane receptor.