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[
Development,
1999]
We have identified a new member of the TGF-beta superfamily, CET-1, from Caenorhabditis elegans, which is expressed in the ventral nerve cord and other neurons.
cet-1 null mutants have shortened bodies and male tail abnormal phenotype resembling sma mutants, suggesting
cet-1,
sma-2,
sma-3 and
sma-4 share a common pathway. Overexpression experiments demonstrated that
cet-1 function requires wild-type sma genes. Interestingly, CET-1 appears to affect body length in a dose-dependent manner. Heterozygotes for
cet-1 displayed body lengths ranging between null mutant and wild type, and overexpression of CET-1 in wild-type worms elongated body length close to lon mutants. In male sensory ray patterning, lack of
cet-1 function results in ray fusions. Epistasis analysis revealed that
mab-21 lies downstream and is negatively regulated by the
cet-1/sma pathway in the male tail. Our results show that
cet-1 controls diverse biological processes during C. elegans development probably through different target genes.
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Baek HK, Song JA, Seo HS, Song KD, Choi DH, Yi SS, Park SK, Kim SJ, Kim PS, Kim DE, Hwang IK, Oh SI
[
J Vet Sci,
2016]
Recently, we reported that Artemisia annua (AA) has anti-adipogenic properties in vitro and in vivo. Reduction of adipogenesis by AA treatment may dampen systemic inflammation and protect neurons from cytokine-induced damage. Therefore, the present study was performed to assess whether AA increases neuronal maturation by reducing inflammatory responses, such as those mediated by COX-2. Mice were fed normal chow or a high-fat diet with or without chronic daily oral administration of AA extract (0.2g/10mL/kg) for 4 weeks; then, changes in their hippocampal dentate gyri were measured with immunohistochemistry/immunofluorescence staining for BrdU, DCX, and NeuN, markers of neuronal maturation, and a quantitative Western blot for COX-2 and Iba-1, in order to assess correlations between systemic inflammation (Il-6) and food type. Additionally, we tested the effect of AA in an Alzheimer's disease model of C. elegans and uncovered a potential benefit. In the present study, we show that chronic AA dosing significantly increases neuronal maturation, particularly in the high-fat diet group. This effect was seen in the absence of any changes in COX-2 levels in mice given the same type of food, pointing to the possibility of alternate anti-inflammatory pathways in the stimulation of neurogenesis and neuro-maturation in a background of obesity.
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[
Nat Commun,
2023]
To ameliorate or even prevent signatures of aging in ultimately humans, we here report the identification of a previously undescribed polyacetylene contained in the root of carrots (Daucus carota), hereafter named isofalcarintriol, which we reveal as potent promoter of longevity in the nematode C. elegans. We assign the absolute configuration of the compound as (3&#
x2009;S,8&#
x2009;R,9&#
x2009;R,E)-heptadeca-10-en-4,6-diyne-3,8,9-triol, and develop a modular asymmetric synthesis route for all E-isofalcarintriol stereoisomers. At the molecular level, isofalcarintriol affects cellular respiration in mammalian cells, C. elegans, and mice, and interacts with the &#
x3b1;-subunit of the mitochondrial ATP synthase to promote mitochondrial biogenesis. Phenotypically, this also results in decreased mammalian cancer cell growth, as well as improved motility and stress resistance in C. elegans, paralleled by reduced protein accumulation in nematodal models of neurodegeneration. In addition, isofalcarintriol supplementation to both wild-type C57BL/6NRj mice on high-fat diet, and aged mice on chow diet results in improved glucose metabolism, increased exercise endurance, and attenuated parameters of frailty at an advanced age. Given these diverse effects on health parameters in both nematodes and mice, isofalcarintriol might become a promising mitohormesis-inducing&#
xa0;compound to delay, ameliorate, or prevent aging-associated diseases in humans.
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[
European Worm Meeting,
2006]
W.K. So, C.M. Chan, M.Y. Wu, W.S. Yeung and K.L. Chow. In dioecious nematodes, finding the mating partner and successful mating is instrumental to their reproductive success. To ensure these tasks are accomplished, sex pheromone production is a common strategy adopted in the nematode world. In Caenorhabditis remanei, a dioecious species, a sex-specific attractant was identified to be produced by females for attracting males. In this study, we focus on four areas of characterization, the properties of the pheromone, its regulatory production in female, male perception and species specification. In the characterization part, our GC-MS analysis result identifies two candidate chemicals in the samples, the exact identity of which will be confirmed by chemical synthesis coupled with bioassays. These attractant substances are produced under tight developmental control in the gonad as confirmed by laser ablation of gonadal progenitor cells in different combination. Their activity could be abolished by mating with males. Based on our pervious results, the males of the androdioecious can be attracted by this sex pheromone. So for the male perception part, we employed males from various Caenorhabditis elegans mutants with defects in cell lineage or molecular function to delineate the perception pathway. Our results show that two different sensory neurons and an interneuron are required. Moreover, a signaling process dependent of G protein coupled receptor is crucial for the pheromone perception, where modulation by other molecular components has been observed. Hypothesis suggesting a conservation of the pheromone perception pathway across different species will be tested using chemo-attraction assay on con-specific and hetero-specific combination of testing animals. (The project is funded by Research Grant Council, Hong Kong.)
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[
International Worm Meeting,
2019]
The maintenance of males at intermediate frequencies is an important evolutionary problem. Several species of Caenorhabditis nematodes have evolved the androdioecious mating system, where selfing hermaphrodites and males coexist. They reproduce mostly through self-fertilization, but can also outcross. While selfing produces XX hermaphrodites, cross-fertilization produces 50% XO male progeny. Thus, male mating success dictates the sex ratio [1]. Here, we focus on the contribution of the male secreted short (mss) gene family to male mating success, sex ratio, and population growth. The mss family is essential for full sperm competitiveness in gonochoristic species, but has been lost in parallel in androdioecious species [2]. Using a transgene to restore mss function to the androdioecious C. briggsae, we examined how mating system and population subdivision influence the fitness of the mss+ genotype. Consistent with theoretical expectations, mss+ is sufficient to increase male frequency and depress population growth in genetically homogenous androdioecious populations. When mss+ and mss-null (i.e. wild-type) genotypes compete, mss+ is positively selected in both mixed-mating and strictly outcrossing situations, though more strongly in the latter. Thus, while sexual mode alone affects the fitness of mss+, it is insufficient to explain its parallel loss. We propose that the lack of inbreeding depression [3] and the strong subdivision that characterize natural Caenorhabditis populations [4] impose selection on sex ratio that makes loss of mss adaptive. By reducing, but not completely eliminating outcrossing, loss of the mss genes tunes the sex ratio to its new optimum after self-fertility is established. 1. Stewart AD, Phillips PC (2002) Genetics 160: 975 2. Yin et al. (2018) Science 359: 55 3. Dolgin et al. (2007) Evolution 61: 1339 4. Kiontke KC, et al. (2011) BMC Evol Biol 11: 339
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[
Worm Breeder's Gazette,
1983]
Use of Colloidal Gold Particles in EM We have been using a simple and inexpensive procedure to produce colloidal gold particles of a uniform size (5 nm) which can be conjugated directly to proteins. Gold particles serve as excellent electron dense markers for use in electron microscopy. Preparation of Colloidal Gold Particles by Ultrasonics 1. Dilute 0.1 ml of 1% gold chloride [ H(AuCl4) ] in 50 ml dH20. 2. Make solution neutral with 0.2M K2CO3. 3. Immediately before sonication, add 0.5 ml of 100% ethanol as a catalyst. 4. Carry out sonication at 20 Kc and 125 W by immersing a flat-end probe approximately 1 cm under the surface of the gold solution. 5. After about 2-5 min, the solution attains a pinkish color with maximum intensity at A = 520 nm. Note: To prevent the solution from heating up during sonication, keep it cool in an ice water bath. This helps prevent the formation of larger gold particles. Store at 4 C. Preparation of Gold Labelled Protein 1. Mix 1mg of purified protein with 5ml of colloidal gold solution and incubate for 15 min at room temperature with mixing. 2. Add 10mg BSA, mix, and incubate for another 5 min to prevent aggregation of gold-protein complexes. 3. Add NaCl (100g/l) to make a final concentration of 10g/l. 4. Centrifuge at 1700 g for 20 min to remove excess BSA. 5. Centrifuge supernatant from step 4 at 60,000 g for 15 min to bring down gold labelled protein, leaving unlabelled protein in the supernatant. 6. Pellet should be a loosely packed, dense red sediment and can be resuspended in 0.5 to 1.0 ml of desired buffer. Use undiluted.
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[
J Biol Chem,
1987]
A sulfated glycoprotein was isolated from the culture media of Drosophila Kc cells and named papilin. Affinity purified antibodies against this protein localized it primarily to the basement membranes of embryos. The antibodies cross-reacted with another material which was not sulfated and appeared to be the core protein of papilin, which is proteoglycan-like. After reduction, papilin electrophoresed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a broad band of about 900,000 apparent molecular weight and the core protein as a narrow band of approximately 400,000. The core protein was formed by some cell lines and by other cells on incubation with 1 mM 4-methylumbelliferyl xyloside, which inhibited formation of the proteoglycan-like form. The buoyant density of papilin in CsCl/4 M guanidine hydrochloride is 1.4 g/ml, that of the core protein is much less. Papilin forms oligomers linked by disulfide bridges, as shown by sodium dodecyl sulfate-agarose gel electrophoresis and electron microscopy. The protomer is a 225 +/- 15-nm thread which is disulfide-linked into a loop with fine, protruding thread ends. Oligomers form clover-leaf-like structures. The protein contains 22% combined serine and threonine residues and 25% combined aspartic and glutamic residues. 10 g of polypeptide has attached 6.4 g of glucosamine, 3.1 g of galactosamine, 6.1 g of uronic acid, and 2.7 g of neutral sugars. There are about 80 O-linked carbohydrate chains/core protein molecule. Sulfate is attached to these chains. The O-linkage is through an unidentified neutral sugar. Papilin is largely resistant to common glycosidases and several proteases. The degree of sulfation varies with the sulfate concentration of the incubation medium. This proteoglycan-like glycoprotein differs substantially from corresponding proteoglycans found in vertebrate basement membranes, in contrast to Drosophila basement membrane laminin and collagen IV which have been conserved evolutionarily.
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[
International C. elegans Meeting,
2001]
One of the least understood aspects of animal development is how growth and body size are regulated 1,2 . Here we show that a signal from the germ-line represses growth in the nematode Caenorhabditis elegans . Laser-microbeam ablation of cells that give rise to the germ-line causes adults to become giant. Ablation of these cells in self-sterile mutant worms also causes gigantism suggesting that the germ-line represses growth because it is the source of a growth-antagonizing signal rather than a sink of resources required for reproduction. The C. elegans germ-line also emits a signal that represses longevity 3 . This longevity-repressing signal requires the activity of DAF-16, a forkhead/winged-helix transcription factor 3 , but we find that that the growth-repressing signal does not. The growth-repressing signal also does not require the activity of DBL-1, a TGF-beta-related protein that promotes growth in worms 4,5 . By ablating the germ-line precursors of other species of free-living nematodes we found that both the growth-repressing and longevity-repressing signals are evolutionarily variable. Some species have both, others have just one or the other. We suggest that variation in germ-line signaling contributes to body size and life-history diversity in the nematodes. 1. I, Conlon, M. Raff, Cell 96, 235 (1999). 2. S. J. Day, P. A. Lawrence, Development 127, 2977 (2000). 3. H. Hsin, C. Kenyon, Nature 399 , 362 (1999). 4. K. Morita, K. L. Chow, N. Ueno, Development 126, 1337 (1999). 5. Y. Suzuki et al ., Development 126, 241 (1999).
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[
J Ethnopharmacol,
2019]
ETHNOPHARMACOLOGICAL RELEVANCE: Sour Jujube seed from Ziziphus jujuba Mill. var. Spinosa (Bunge) Hu ex H. F. Chow is a traditional Chinese herb. It was demonstrated with significant activities in anti-depression and antioxidant by numerous pharmacological studies. Flavonoids is one of the main constituents in sour Jujube seed. AIM OF THE STUDY: The aim of this study was to propose a green ultrasound-assisted extraction (UAE) process of flavonoids from sour Jujube seed. MATERIALS AND METHODS: The extraction parameters were investigated and optimized using single factor experiments, Plackett-Burman design (PBD) and response surface methodology (RSM). Moreover, a comparative analysis between ultrasound-assisted extraction and heat reflux extraction was performed to verify the ameliorating effects of ultrasound-assisted extraction on the flavonoids yield, the composition, antioxidant capacities in vitro and ROS scavenging capacity in PC12cells. Meanwhile, the effects of flavonoids extract (FE) on A transgenic Caenorhabditis elegans (GMC101) behavior were investigated. RESULTS: The optimal extracting conditions of total flavonoids were as follows: ethanol concentration 70.60 (v/v%), liquid-solid ratio 15.02:1mL/g, ultrasonic power 404W, extraction time 60.03min. The highest extraction yield was 1.59%. When compared to Heat reflux extraction (HRE) that only has gained a yield of 1.356%. Approximately, the UAE method was able to increase the yield by 17.11%. Moreover, FE extracted by UAE displayed larger capacity of scavenging ABTS, DPPH, superoxide, and hydroxyl radicals and reducing the level of ROS accumulation in PC12cells, suggesting the biological functions of these compounds could be also better protected under UAE conditions. Furthermore, FE could also increase the chemotaxis and heat stress resistance ability, delay the paralysis and extend the lifespan of Caenorhabditis elegans. CONCLUSION: UAE is a green and efficient technique for the preparation of flavonoids from sour Jujube seed. The flavonoids extract can reduce A-induced toxicity in Caenorhabditis elegans.
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[
East Coast Worm Meeting,
2002]
Ray pattern is one of the most variable morphological characters in rhabditid nematodes. C. elegans and C. remanei exhibit a 2(1)3+3 pattern in which ray 3 is separate from other rays and located at the anus. This pattern is ancestral in the 'elegans group' of Caenorhabditis (Sudhaus and Kiontke, 1996). A derived 2/4+3 ray pattern in which ray 3 is posterior of the anus and frequently fused with ray 4 is diagnostic for C. briggsae. However, this pattern is not fixed and three C. briggsae strains have been identified that exhibit both the derived and ancestral patterns (Baird, 2001). Using this variation, it should be possible to identify the genes responsible for ray pattern evolution in Caenorhabditis. Phenotypic segregation has demonstrated that ray pattern variation in C. briggsae results from allelic variation at two or three major-effect genes. Analyses of mutant phenotypes in C. elegans suggest that ray pattern evolution may result from alterations of HOM-C/Hox gene expression patterns (Chow and Emmons, 1994). Alterations in anteroposterior positional information also may account for evolutionary changes in the P3.p cell lineage. In C. briggsae, P3.p cell division frequency exhibits strain-specific variation (Dellatre and Flix, 2001). This variation correlates with ray pattern variation in C. briggsae males. To confirm this correlation, ray pattern and P3.p cell division frequency are being tested for cosegregation in crosses between variant strains. Single nucleotide polymorphisms (SNPs) from several C. briggsae strains are being identified at the Washington University Genome Sequencing Center. These SNPs will be used to map the genes responsible for ray pattern and P3.p cell division frequency variation. Initial experiments will focus on candidate genes known to regulate HOM-C/Hox gene expression patterns. If no linkage to candidates is detected, recombination mapping will proceed with SNPs distributed throughout the genome. Baird, S. E. (2001) Strain-specific variation in the pattern of caudal papillae in Caenorhabditis briggsae (Nematoda; Rhabditidae); implications for species identification. Nematology 3: 373-376.