Plenefisch JD et al. (1994) Worm Breeder's Gazette "Cloning mua-3: Some Observations on the New Molecular Era"

Plenefisch JD, Hedgecock EM

[Worm Breeder's Gazette, 1994]

Cloning mua-3: some observations on the new Molecular Era John Plenefisch and Edward Hedgecock, Dept. of Biology, Johns Hopkins University, Baltimore MD 21218

Parham C et al. (1994) Worm Breeder's Gazette "Tc4 and Tc5: What Makes Them Move and Why It Matters"

Beinhorn J, Collins JJ, Butze K, Parham C

[Worm Breeder's Gazette, 1994]

Tc4 and Tc5: what makes them move and why it matters Christi Parham, Kristie Butze, Joanna Beinhorn and John Collins. Dept. of Biochemistry and Molecular Biology, University of New Hampshire. Durham, NH 03824

Nathan A Dunn et al. (2003) International Worm Meeting "A Survey of Neural Network Models for Chemotaxis in C. elegans"

Shawn R Lockery, Nathan A Dunn, John S Conery

[International Worm Meeting, 2003]

C. elegans chemotaxis involves bouts of turning (pirouettes) modulated by the rate of change of attractant concentration. A candidate neural network for chemotaxis in C. elegans is emerging several ablation studies. The aim of this research is to generate testable models of how the chemotaxis network computes the sensorimotor transformation. Neurons in the models were passive, isopotential electrical compartments that mimicked likely biophysical properties of C. elegans neurons. Networks began with ten neurons: a sensory neuron representing the chemosensory neurons, an output neuron representing the state of the locomotory command neurons, and eight generic interneurons. Neurons were fully interconnected with self-connections. The input to the sensory neuron was attractant concentration C(t) recorded from a real worm during a chemotaxis assay. Pirouette probability P(t) in the model was determined according to the activity state of the output neuron. Networks were optimized by adjusting neuronal time constants and connection strengths via an interactive search algorithm (simulated annealing) until P(t) was high when dC/dt<0 and P(t) was low when dC/dt>0, as in real worms. After optimization we eliminated interneurons that did not have a significant effect on P(t); 63% of our networks could be reduced to one interneuron. One-interneuron networks had three common features. (1) A differentiation circuit involving a rapid, excitatory, monosynaptic pathway from the input neuron to the output neuron in parallel with a delayed, inhibitory disynaptic pathway via the interneuron. Thus, the activity of the output neuron reflected the difference between present and previous values of C(t), an approximation to dC/dt. (2) Strong inhibitory self-connections on the input and output neurons, but a weak inhibitory self-connection on the interneuron. Mathematical analysis of self-connections showed that they decreased the effective time constant of the neurons. We tested this by training a set of networks with a delay between C(t) and desired pirouette probability. The magnitude of the inhibitory self-connections varied inversely to the delay, as expected. (3) Recurrent inhibitory connections between all pairs of neurons. Analysis of the recurrent connections suggested that they stabilize activity of neurons. Anatomical substrates for all three features have been found in previous reconstructions of the C. elegans nervous system; our results provide hypothetical functions for these patterns of connectivity. We are currently analyzing the common features of the multi-interneuron networks. Support: NSF IBN0080068.

Almeida CA et al. (1994) Worm Breeder's Gazette "Function of a Domain of the Myosin Heavy Chain Implicated in Familial Hypertrophic Cardiomyopathy"

Collins JJ, Almeida CA, Swift KE

[Worm Breeder's Gazette, 1994]

Function of a Domain of the Myosin Heavy Chain Implicated in Familial Hypertrophic Cardiomyopathy Craig A. Almeida, Kerry E. Swift and John J. Collins Department of Biochemistry and Molecular, University of New Hampshire, Durham, NH 03820

Chalfie M (1993) J Neurobiol "Touch receptor development and function in Caenorhabditis elegans."

Chalfie M

[J Neurobiol, 1993]

Mutations causing a touch-insensitive phenotype in the nematode Caenorhabditis elegans have been the basis of studies on the specification of neuronal cell fate, inherited neurodegeneration, and the molecular nature of mechanosensory transduction. (C) 1993 John Wiley & sons, Inc.

Maine EM et al. (1994) Worm Breeder's Gazette "Mutations That Enhance glp-1 Identify Genes Required For Various Aspects of Germline Development."

Gelber MB, Smardon AM, Shu P, Qiao L, Maine EM, Lissemore JL

[Worm Breeder's Gazette, 1994]

Mutations that enhance glp-1 identify genes required for various aspects of germline development. Eleanor Maine, Li Qiao, Jim Lissemore-, Pei Shu, Anne Smardon, and Melanie Gelber. Biology Dept., Syracuse University, Syracuse, NY 13244 and Biology Dept., John Carroll University, Cleveland, OH 44118.

Vinci CR et al. (2007) J Biol Chem "Recognition of age-damaged (R,S)-adenosyl-L-methionine by two methyltransferases in the yeast Saccharomyces cerevisiae."

Vinci CR, Clarke SG

[J Biol Chem, 2007]

The biological methyl donor, S adenosylmethionine (AdoMet), can exist in two diastereoisomeric states with respect to its sulfonium ion. The "S" configuration, (S,S)AdoMet, is the only form that is produced enzymatically as well as the only form used in almost all biological methylation reactions. Under physiological conditions, however, the sulfonium ion can spontaneously racemize to the "R" form, producing (R,S)AdoMet. As of yet, (R,S)AdoMet has no known physiological function and may inhibit cellular reactions. In this study, two enzymes have been found in Saccharomyces cerevisiae that are capable of recognizing (R,S)AdoMet and using it to methylate homocysteine to form methionine. These enzymes are the products of the SAM4 and MHT1 genes, previously identified as homocysteine methyltransferases dependent upon AdoMet and S-methylmethionine respectively. We find here that Sam4 recognizes both (S,S) and (R,S)AdoMet, but its activity is much higher with the R,S form. Mht1 reacts with only the R,S form of AdoMet while no activity is seen with the S,S form. R,S-specific homocysteine methyltransferase activity is also shown here to occur in extracts of Arabidopsis thaliana, Drosophila melanogaster, and Caenorhabditis elegans, but has not been detected in several tissue extracts of Mus musculus. Such activity may function to prevent the accumulation of (R,S)AdoMet in these organisms.

Chalfie M (1998) Nature "Genome sequencing. The worm revealed."

Chalfie M

[Nature, 1998]

In 1983, John Sulston and Alan Coulson began to construct a complete physical map of the genome of the nematode worm Caenorhabditis elegans, and started what became known as the C. elegans Genome Project. At the time, several people wondered why John, who had just described all of the cell divisions in C. elegans (the cell lineage), was interested in this project rather than in a more 'biological' problem. He replied by joking that he had a "weakness for grandiose, meaningless projects". In 1989, as the physical map approached completion, the Genome Project, now including Bob Waterston and his group, embarked on the even more ambitious goal of obtaining the complete genomic sequence

Fanning S et al. (2018) Mol Cell "Lipidomic Analysis of -Synuclein Neurotoxicity Identifies Stearoyl CoA Desaturase as a Target for Parkinson Treatment."

Lou Y, Haque A, Freyzon Y, Farese RV, Terry-Kantor E, Hofbauer HF, Termine D, Welte MA, Barrasa MI, Imberdis T, Noble T, Lindquist S, Clish CB, Jaenisch R, Pincus D, Nuber S, Sandoe J, Kohlwein SD, Kim TE, Ho GPH, Ramalingam N, Walther TC, Baru V, Selkoe D, Srinivasan S, Landgraf D, Soldner F, Dettmer U, Fanning S, Becuwe M, Newby G

[Mol Cell, 2018]

In Parkinson's disease (PD), -synuclein (S) pathologically impacts the brain, a highly lipid-rich organ. We investigated how alterations in S or lipid/fattyacid homeostasis affect each other. Lipidomic profiling of human S-expressing yeast revealed increases in oleic acid (OA, 18:1), diglycerides, and triglycerides. These findings were recapitulated in rodent and human neuronal models of S dyshomeostasis (overexpression; patient-derived triplication or E46K mutation; E46K mice). Preventing lipid droplet formation or augmenting OA increased S yeast toxicity; suppressing the OA-generating enzyme stearoyl-CoA-desaturase (SCD) was protective. Genetic or pharmacological SCD inhibition ameliorated toxicity in S-overexpressing rat neurons. In a C.elegans model, SCD knockout prevented S-induced dopaminergic degeneration. Conversely, we observed detrimental effects of OA on S homeostasis: in human neural cells, excess OA caused S inclusion formation, which was reversed by SCD inhibition. Thus, monounsaturated fatty acid metabolism is pivotal for S-induced neurotoxicity, and inhibiting SCD represents a novel PD therapeutic approach.

Vandecandelaere I et al. (2017) PLoS One "Metabolic activity, urease production, antibiotic resistance and virulence in dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus."

Deforce D, Coenye T, Van Nieuwerburgh F, Vandecandelaere I

[PLoS One, 2017]

In this paper, the metabolic activity in single and dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus isolates was investigated. Our results demonstrated that there was less metabolic activity in dual species biofilms compared to S. aureus biofilms. However, this was not observed if S. aureus and S. epidermidis were obtained from the same sample. The largest effect on metabolic activity was observed in biofilms of S. aureus Mu50 and S. epidermidis ET-024. A transcriptomic analysis of these dual species biofilms showed that urease genes and genes encoding proteins involved in metabolism were downregulated in comparison to monospecies biofilms. These results were subsequently confirmed by phenotypic assays. As metabolic activity is related to acid production, the pH in dual species biofilms was slightly higher compared to S. aureus Mu50 biofilms. Our results showed that S. epidermidis ET-024 in dual species biofilms inhibits metabolic activity of S. aureus Mu50, leading to less acid production. As a consequence, less urease activity is required to compensate for low pH. Importantly, this effect was biofilm-specific. Also S. aureus Mu50 genes encoding virulence-associated proteins (Spa, SplF and Dps) were upregulated in dual species biofilms compared to monospecies biofilms and using Caenorhabditis elegans infection assays, we demonstrated that more nematodes survived when co-infected with S. epidermidis ET-024 and S. aureus mutants lacking functional spa, splF or dps genes, compared to nematodes infected with S. epidermidis ET-024 and wild- type S. aureus. Finally, S. epidermidis ET-024 genes encoding resistance to oxacillin, erythromycin and tobramycin were upregulated in dual species biofilms and increased resistance was subsequently confirmed. Our data indicate that both species in dual species biofilms of S. epidermidis and S. aureus influence each other's behavior, but additional studies are required necessary to elucidate the exact mechanism(s) involved.