Bowerman BA et al. (1994) Worm Breeder's Gazette "The Maternal Gene skn-4 and the Specification of Ventral Blastomere Fates in the Early C. elegans Embryo"

Bowerman BA, Shelton CA, Thorpe CJ, Martin PR

[Worm Breeder's Gazette, 1994]

THE MATERNAL GENE SKN-4 AND THE SPECIFICATION OF VENTRAL BLASTOMERE FATES IN THE EARLY C. ELEGANS EMBRYO Bruce Bowerman, Paula R. Martin, Christopher J. Thorpe, and Christopher A. Shelton. The Institute of Molecular Biology, University of Oregon, Eugene, OR 97403.

Douglas, Chandler et al. (2010) C. elegans: Development and Gene Expression, EMBL, Heidelberg, Germany "The effects of nickel-spiked sediments upon survival, growth, and reproduction in Caenorhabditis elegans."

Crisp, Laddie, Douglas, Chandler, Rudel, David, Besser, John, Ingersoll, Christopher

[C. elegans: Development and Gene Expression, EMBL, Heidelberg, Germany, 2010]

Little is known about the integration of environmental effects upon development. Recently, a great deal of interest in this field has arisen through the use of model organisms as bio-indicators of environmental stressors. We are developing tests to look at the affects of nickel on ecosystem health using C. elegans. Nickel is a common heavy metal contaminant in waterways due to mining, industry, and human wastes. We conducted three tests on two sediments from distinct locations comparing results from un-spiked and spiked nickel samples. For all tests, we placed sediment in the wells of 12-well culture plates. Quantified antibiotic killed E. coli is added as a food source and all nematode cultures grown at 20C. In the first test we evaluated longevity by placing ~55 L4 fog-2 animals into each well. Individual wells were harvested for surviving worms for 21 successive days. In the second test we placed 10 synchronized L1 larvae into wells for four days. Fixed, harvested animals were observed for life stage, gravidity, and growth (length and width). In the third test we placed 10 synchronized L1 larvae in wells for eight days. Fixed, harvested animals were counted for the total number of adults and larvae in each well. Nickel has a strong affect upon adult survival, developmental growth, and fecundity. At our highest levels of nickel, all fog-2 animals die within a week. Animals that are observed within the first week often have a stunted appearance. In comparison the majority of fog-2 animals survive into their third week as adults in un-spiked control sediment. Not surprising, L1 larvae mostly fail to survive either the four- or eight-day study. When they do survive they appear to be arrested in the L3 larval stage. Ultimately we hope to use these assays not only for measurements of nickel toxicity, but also to provide the material for expression studies on developmental genes impacted by heavy metal contamination.

Christopher J Cronin et al. (2005) International Worm Meeting "The Combined UC San Diego/Caltech Quantitative Behavior Analysis System"

William R Schafer, Zhaoyang Feng, Kuang-man Huang, Paul W Sternberg, Christopher J Cronin

[International Worm Meeting, 2005]

California Institute of Technology and University of California, San Diego have each developed practical, automated movement analysis systems to quantify aspects of worm behavior and morphology (see An imaging system for standardized quantitative analysis of C. elegans behavior, Zhaoyang Feng, et al, BMC Bioinformatics 2004, 5:115, An automated system for measuring parameters of nematode sinusoidal movement, Christopher J Cronin, et al, BMC Genetics 2005, 6:5, and previous meeting abstracts). We have consolidated our development efforts and merged our independent system designs to create a single, unified behavior analysis system. The combined system provides researchers with all of the quantification tools and database functionality of the individual UCSD and Caltech systems, but also establishes a common, open software and hardware foundation for continued development by Caltech, UCSD and the community. Current efforts include expanding system capabilities for the automated analysis of mating behavior with the challenge of tracking multiple moving individuals, both in contact with and separated from each other.

Pena-Gonzalez, I. et al. (2013) International Worm Meeting "Suppressors of TDP-1 toxicity in Caenorhadbitis elegans."

Link, CD., Pena-Gonzalez, I.

[International Worm Meeting, 2013]

Suppressors of TDP-1 toxicity in Caenorhadbitis elegans Ilana Pena-Gonzalez1 and Christopher D Link1, 2 1 Integrative Physiology, University of Colorado, Boulder, CO 80309, USA 2 Institute for Behavioral Genetics, University of Colorado, Boulder, CO 80309, USA RNA binding protein TDP-43 forms damaging aggregates in multiple neurodegenerative diseases. We have found that the deletion of tdp-1, the C. elegans ortholog of TDP-43, leads to increased accumulation of double stranded RNA. TDP-1 is not believed to bind to dsRNA itself; however the marked increase in dsRNA accumulation in worms deleted for tdp-1 implies TDP-1 normally participates in limiting the stability and structure of dsRNA. Although worms deleted for TDP-1 do not have a severe phenotype, overexpressed nuclear TDP-1 is toxic in worms. One possible explanation for this is that too much TDP-1 leads to excessive disruption of structured RNAs needed for normal RNA metabolism. Making use of this overexpression model we have established a heat shock induction system to help identify components associated with TDP-1's prevention of dsRNA accumulation. Identifying mutations that suppress the neurotoxic effects of overexpressed TDP-1 could help identify others factors contributing to the complex mechanism of disassembling dsRNA. A mutagenesis screen has identified four mutant strains that partially suppress the toxicity of overexpressed TDP-1. We have also tested suppressors of other toxic proteins. Further identifying the pieces of the mechanism regulating dsRNA breakdown could help better explain the pathogenic pathway of TDP-1 and consequently TDP-43 in disease.

Bauer CC et al. (1998) West Coast Worm Meeting "a, b AND g-FILAGENIN - NEW PROTEINS IN THE CORE'S OF THICK FILAMENTS"

Schmid MF, Ortiz I, Epstein HF, Liu FZ, Bauer CC

[West Coast Worm Meeting, 1998]

The cores of muscle thick filaments are composed of an outer layer of paramyosin surrounding an inner tubular region containing additional core proteins. In order to study the structure of the thick filament core and the mechanisms and molecules involved in the formation of this length-regulated, multi-protein structural assemblage, we have isolated and characterized three novel proteins: a, b and g-filagenin. We obtained partial peptide sequences from each of the filagenin proteins and determined their predicted protein sequences from the C. elegans Genome Project's database and correlated this information with cDNA sequence obtained from RT-PCR or phage libraries. All three filagenins are novel proteins with no significant homologies to any known proteins (although homologues in parasitic nematodes have been found in the databases). All filagenins also possess the distinction of having calculated isoelectric points of over pH 10 and having a higher than average number of aromatic amino acids. Both b and g-filagenin are predicted to have secondary structures containing only beta strands and loops, whereas a-filagenin is composed of both alpha helices and beta strands. Structural studies of the core indicate that there are seven paramyosin subfilaments crosslinked by additional internal proteins. We tested our structural model with Western blotting using an affinity-purified antibody and have showed that a, b and g-filagenins are associated with the cores. All three filagenins were localized by immunofluorescence microscopy to the A bands of body wall muscles, but there was no detectable reaction with the pharynx, with the exception of a slight reaction with anti-a-filagenin antibody. b-Filagenin has been shown by immunoelectron microscopy to be assembled with paramyosin into the tubular cores of wild-type nematodes at the same periodicity of 72-nm as observed with paramyosin. In CB1214 paramyosin null mutants, b-filagenin assembles with myosin to form abnormal tubular filaments with a periodicity identical to that of wild type. These results verify that the filagenins are core proteins that co-assemble with either myosin or paramyosin in C. elegans to form tubular filaments. Further studies on nematode muscle thick filaments are intended to elucidate the mechanisms behind the formation and regulation of these stable assemblies of myosin and associated proteins. *Supported by grants from the Muscular Dystrophy Association, the National Science Foundation and a NRSA postdoctoral fellowship for Christopher Bauer.