Shakambari G et al. (2015) Indian J Exp Biol "Phlorotannins from Brown Algae: inhibition of advanced glycation end products formation in high glucose induced Caenorhabditis elegans."

Ashokkumar B, Varalakshmi P, Shakambari G

[Indian J Exp Biol, 2015]

Advanced Glycation End products (AGE) generated in a non enzymatic protein glycation process are frequently associated with diabetes, aging and other chronic diseases. Here, we explored the protective effect of phlorotannins from brown algae Padina pavonica, Sargassum polycystum and Turbinaria ornata against AGEs formation. Phlorotannins were extracted from brown algae with methanol and its purity was analyzed by TLC and RP-HPLC-DAD. Twenty five grams of P. pavonica, S. polycystum, T. ornata yielded 27.6 +/- 0.8 g/ml, 37.7 g/ml and 37.1 +/- 0.74 g/ml of phloroglucinol equivalent of phlorotannins, respectively. Antioxidant potentials were examined through DPPH assay and their IC50 values were P. pavonica (30.12 +/- 0.99 g), S. polycystum (40.9 +/- 1.2 g) and T. ornata (22.9 +/- 1.3 g), which was comparatively lesser than the control ascorbic acid (46 +/- 0.2 g). Further, anti-AGE activity was examined in vitro by BSA-glucose assay with the extracted phlorotannins of brown algae (P. pavonica, 15.16 +/- 0.26 g/ml; S. polycystum, 35.245 +/- 2.3 g/ml; T. ornata, 22.7 +/- 0.3 g/ml), which revealed the required concentration to inhibit 50% of albumin glycation (IC50) were lower for extracts than controls (phloroglucinol, 222.33 +/- 4.9 g/ml; thiamine, 263 g/ml). Furthermore, brown algal extracts containing phlorotannins (100 l) exhibited protective effects against AGE formation in vivo in C. elegans with induced hyperglycemia.

(2021) Development "The people behind the papers - Brandon Carpenter and David Katz."

[Development, 2021]

A dynamic pattern of histone methylation and demethylation controls gene expression during development, with some processes such as formation of the zygote involving large-scale reprogramming of methylation states. A new paper in Development investigates how inherited histone methylation regulates developmental timing and the germline/soma distinction in <i>Caenorhabditis elegans</i> To hear more about the story we caught up with first author and postdoctoral researcher Brandon Carpenter, and his supervisor David Katz, Associate Professor in the Department of Cell Biology at Emory University School of Medicine in Atlanta, Georgia.

Nicole Charlie et al. (2006) Neuronal Development, Synaptic Function, and Behavior Meeting "A High Energy Light Signal Transduction Pathway Impinges on the Synaptic Signaling Network"

Marie Milfort, Nicole Charlie, Stacey Williams, Kenneth Miller, Brandon Brown

[Neuronal Development, Synaptic Function, and Behavior Meeting, 2006]

Genetic studies suggest that the integrated activities of at least 3 major G alpha pathways control synaptic activity to produce the C. elegans locomotion behavior. In this network, a core EGL-30 (Gq) pathway drives locomotion by a mechanism that is dependent on the UNC-13 synaptic vesicle priming protein. UNC-31, a dense-core vesicle priming protein, is required for activation of a functionally distinct but interacting neuronal Gs pathway, which drives locomotion by a mechanism that is dependent on the Gq pathway. Strong reduction-of-function mutants in the Gq pathway or UNC-13, and null mutants in UNC-31 or the neuronal Gs pathway are nearly paralyzed, with locomotion rates ~1 - 3% of wild type. We recently made the startling observation that blue light causes both wild type and unc-31 null mutants to begin moving hyperactively in a coordinated manner. Using different filters and light equipment to control and measure the light fluence, we found that the action spectrum peaks in the UV range, and that worms are unresponsive to green and orange light, even at very high fluence. The response is not caused by small temperature changes induced by the light, since green light causes a greater temperature change than blue-violet light of the same power. The response is photophobic, originates in the nerve cords, begins within 1-2 sec (for wild type), and is saturable. Bathing paralyzed egl-30(ad805) mutants in optimal light restores coordinated wild type locomotion but doesn"t make them hyperactive as is the case for unc-31 and neuronal Gs pathway nulls. In contrast, similarly paralyzed unc-13 mutants are unresponsive to light. Our results suggest that high energy light activates a pathway that plugs into a downstream component of the synaptic signaling network and affects a process that is dependent on UNC-13. To investigate the mechanism of this response, we carried out a large forward genetic screen for mutants that are unresponsive to high energy light but have near-wild type sensitivity to physical stimuli. We found 19 Lite mutants, representing 1 principal target (lite-1) and 1 or more rare targets. We have mapped lite-1 to a physical interval and are testing candidate genes for lite-1 mutations.

Ishii K et al. (2001) Heredity "Sexual isolation and cuticular hydrocarbons in Drosophila elegans."

Hirai Y, Katagiri C, Kimura MT, Ishii K

[Heredity, 2001]

In Drosophila elegans, partial sexual isolation has developed between the brown and black morphs, which are distributed allopatrically. The present study aims to understand how they discriminate between potential mates. Mating experiments show that the females of the two morphs differ in sexual signal(s) and the males discriminate using these differences. Body colouration is not used as a sexual cue in this species. Between the females of the two morphs, a large difference was observed in the percentages of 7-pentacosene and 9-pentacosene on the cuticle. Genetical analysis using recombinant inbred lines supported the possibility that the concentration of these pentacosenes plays a role in mate discrimination of these two morphs. However, males did not respond to killed females at all, suggesting that cuticular hydrocarbons of females are not the only cue for the induction of male courtship behaviour. It may be that unknown signals or substances are essential to induce male courtship and pentacosenes modulate the attractiveness of females, positively in the black morph and negatively in the brown morph. Drosophila elegans F1 offspring had intermediate characteristics in mate discrimination and hydrocarbon composition between the parental brown and black morph strains. The number of loci responsible for the differences in the concentration of pentacosenes and the male and female components in the mate recognition between these two morphs is suggested to be more than one.

Stacey Williams et al. (2007) International Worm Meeting "LITE-1: a novel light receptor that mediates the C. elegans light response and the light - driven rescue of paralyzed synaptic signaling mutants."

Nicole Charlie, Brandon Brown, Kenneth Miller, Marie Milfort, Christen Gravlin, Jamie Knecht, Stacey Williams

[International Worm Meeting, 2007]

C. elegans is often described as a soil organism and is not known to need a response to light. However, we found that C. elegans has a robust locomotory response to blue and shorter wavelengths of light, with maximal sensitivity to UV light. The light response does not correlate with light-induced temperature changes. It is present from birth onward, including dauers, and is a survival strategy, because extended illumination with blue and shorter wavelengths kills C. elegans by a temperature-independent mechanism. The light response has the astonishing ability to restore wild type levels of coordinated locomotion to mutants with strongly impaired presynaptic G<font face=symbol>a</font>q or G<font face=symbol>a</font>s pathways, which are nearly paralyzed under normal light conditions, but it cannot rescue similarly paralyzed mutants with defects in synaptic vesicle priming. Using a forward genetic screen we identified LITE-1, an eight-transmembrane protein and member of the large Gustatory Receptor family, as the major mediator of the light response. Pan-neuronal expression of LITE-1 rescues a lite-1 null mutant, but activation of LITE-1 just in tail neurons also fully rescues the light response and the light-driven rescue of paralyzed synaptic signaling mutants. LITE-1 has no homology to G protein - coupled receptors, and our 20-fold coverage genetic screen did not identify a G<font face=symbol>a</font> protein involved in the response. Transgenic expression of LITE-1 in body wall muscles causes a tissue that is normally light-insensitive to become light-sensitive, thus demonstrating that LITE-1 is a light receptor. The light sensitivity takes the form of a powerful contraction of muscle cells that begins within 300 msec of exposure to short-wavelength light. We are currently using Cameleon FRET imaging of cultured muscle cells to test whether LITE-1 is coupled to the opening of calcium channels or the release of calcium from internal stores, and we are attempting to identify the source of calcium using various genetic and pharmacological tools. Our results reveal a novel sensory modality in C. elegans that is mediated by a new kind of light receptor coupled to a novel signal transduction mechanism involving calcium mobilization.

Michael A Beer (2005) International Worm Meeting "Systematic genome-wide identification of transcriptional cis-regulatory logic in C. elegans."

Michael A Beer

[International Worm Meeting, 2005]

We have developed a systematic approach for inferring cis-regulatory logic from whole-genome microarray expression data.[1] This approach identifies local DNA sequence elements and the combinatorial and positional constraints that determine their context-dependent role in transcriptional regulation. We use a Bayesian probabilistic framework that relates general DNA sequence features to mRNA expression patterns. By breaking the expression data into training and test sets of genes, we are able to evaluate the predictive accuracy of our inferred Bayesian network. Applied to S. cerevisiae, our inferred combinatorial regulatory rules correctly predict expression patterns for most of the genes. Applied to microarray data from C. elegans[2], we identify novel regulatory elements and combinatorial rules that control the phased temporal expression of transcription factors, histones, and germline specific genes during embryonic and larval development. While many of the DNA elements we find in S. cerevisiae are known transcription factor binding sites, the vast majority of the DNA elements we find in C. elegans and the inferred regulatory rules are novel, and provide focused mechanistic hypotheses for experimental validation. Successful DNA element detection is a limiting factor in our ability to infer predictive combinatorial rules, and the larger regulatory regions in C. elegans make this more challenging than in yeast. Here we extend our previous algorithm to explicitly use conservation of regulatory regions in C. briggsae to focus the search for DNA elements. In addition, we expand the range of regulatory programs we identify by applying to more diverse microarray datasets.[3] 1. Beer MA and Tavazoie S. Cell 117, 185-198 (2004). 2. Baugh LR, Hill AA, Slonim DK, Brown EL, and Hunter, CP. Development 130, 889-900 (2003); Hill AA, Hunter CP, Tsung BT, Tucker-Kellogg G, and Brown EL. Science 290, 809812 (2000). 3. Baugh LR, Hill AA, Claggett JM, Hill-Harfe K, Wen JC, Slonim DK, Brown EL, and Hunter, CP. Development 132, 1843-1854 (2005); Murphy CT, McCarroll SA, Bargmann CI, Fraser A, Kamath RS, Ahringer J, Li H, and Kenyon C. Nature 424 277-283 (2003); Reinke V, Smith HE, Nance J, Wang J, Van Doren C, Begley R, Jones SJ, Davis EB, Scherer S, Ward S, and Kim SK. Mol Cell 6 605-616 (2000).

Nolan RA (1972) Mycologia "Asteromyces cruciatus from North America."

Nolan RA

[Mycologia, 1972]

The hyphomycete Asteromyces cruciatus F. & Mme Moreau was described without a Latin diagnosis or a designated type. The taxon was validated by Hennebert. The known distribution of this monotypic genus has been limited. F. and Mme Moreau found the fungus in sand dunes at Point du Siege (under Psamma sp.) and between Franceville and Le Home (under Agropyrum sp.) on the Normandy coast of France. Brown found A. cruciatus in open sand in the intertidal zone at Studland, Dorset and Sandwich, Kent, England; and Nicot found it in sand dunes and beach samples at Malo-les-Bains on the North Sea coast of France.

Erich M Schwarz et al. (2003) International Worm Meeting "Comparative analysis of cis-regulatory sequences using four Caenorhabditis species."

Nora Mullaney, Erich M Schwarz, Tristan De Buysscher, Paul W Sternberg, Barbara J Wold, John A DeModena, Eunpyo Moon, Hiroaki Shizuya

[International Worm Meeting, 2003]

Comparing homologous cis-regulatory DNA sequences from three or more genomes has advantages over pairwise comparison of only two. Cis-regulatory sequences are short (6-20 bp) and tolerate substantial variation. Purely random pairing of unrelated 100-bp DNA segments is expected to yield two perfect 6 bp matches. Alignment of a third or fourth sequence should greatly lower the frequency of false positive regions, allowing small but real cis-regulatory sequences to be efficiently detected. This increased resolution should also allow direct comparison between phylogenetically conserved sequences and statistically overrepresented sequences, which may yield complementary views of regulatory elements. In the Caenorhabditis genus, C. remanei appears to be most closely related to C. briggsae; two other species, CB5161 and PS1010, comprise the two closest known and culturable Caenorhabditis species outside the elegans-briggsae group (Fitch, 2000). CB5161 is closest to C. elegans, and PS1010 the next most divergent; these two species thus provide an evolutionarily graded series. We have constructed fosmid libraries from CB5161 and PS1010, and begun sequencing individual fosmids for comparative analysis of genes involved in vulval or sensory neuron development. At the same time, we have devised the Mussa software package to adapt the algorithms of Davidson and coworkers (Brown et al., 2002) to multiple sequence analysis. At this writing, we have sequence data from the egl-30, lin-11, and mab-5 loci of both CB5161 and PS1010. Initial results of sequencing and comparative sequence analysis will be presented. References: Brown, C.T., Rust, A.G., Clarke, P.J., Pan, Z., Schilstra, M.J., De Buysscher, T., Griffin, G., Wold, B.J., Cameron, R.A., Davidson, E.H., and Bolouri, H. (2002). New computational approaches for analysis of cis-regulatory networks. Dev. Biol. 246, 86-102; Fitch, D.H.A. (2000). Evolution of Rhabditidae and the male tail. J. Nematol. 32, 235-244.

Walker JE et al. (1993) J Bioenerg Biomembr "The mitochondrial transport protein superfamily."

Runswick MJ, Walker JE

[J Bioenerg Biomembr, 1993]

The ADP/ATP, phosphate, and oxoglutarate/malate carrier proteins found in the inner membranes of mitochondria, and the uncoupling protein from mitochondria in mammalian brown adipose tissue, belong to the same protein superfamily. Established members of this superfamily have polypeptide chains approximately 300 amino acids long that consist of three tandem related sequences of about 100 amino acids. The tandem repeats from the different proteins are interrelated, and probably have similar secondary structures. The common features of this superfamily are also present in nine proteins of unknown functions characterized by DNA sequencing in various species, most notably in Caenorhabditis elegans and Saccharomyces cerevisiae. The high level expression in Escherichia coli of the bovine oxoglutarate/malate carrier, and the reconstitution of active carrier from the expressed protein, offers encouragement that the identity of superfamily members of known sequence but unknown function may be uncovered by a similar route.

Mohamed ASA et al. (2000) Journal of Pesticide Science "Lethal activity of galo- and condensed tannins against the free-living soil-inhabiting nematode, Caenorhabditis elegans."

Mohamed ASA, Sato M, Islam SQ, Yamasaki T, Mori T

[Journal of Pesticide Science, 2000]

Great amounts of structurally diverse tannins are annually produced. Tannins have been well known as food phytochemicals (e.g. 3T-O-a-L-arabinopyranosyl-ent-epicatechin-(2a->O-7,4a->8)-epicat echin in cacao mass), medicinal properties (e.g. geraniin in Geranium thunbergii as tonic or antidiarrhoic) or tanning materials for leather manufacture (e.g. wattle tannins in Acacia mollissima). Recently, condensed tannin dimers (procyanidins B-1 and B-3) and its polymers were isolated from Pinus densiflora and characterized as members of the oviposition-stimulating multicomponent system in pine for the cerambycid beetle, Monochamus alternatus. Condensed tannins have also been regarded as antifeedants for phytophagous insects. A marine phlorotannin preparation, polymer of phloroglucinol, obtained from the brown alga Sargassum furvellum inhibits growth of the green algae Dunaliella and Enteromorpha spp. This paper describes isolation and identification of gallo- and condensed tannins and their nematicidal acitivity against the soil-inhabiting nematode, Caenorhabditis elegans.