Ghosh-Roy A et al. (2010) Dev Dyn "Caenorhabditis elegans: a new model organism for studies of axon regeneration."

Chisholm AD, Ghosh-Roy A

[Dev Dyn, 2010]

Axonal regeneration in Caenorhabditis elegans was first reported five years ago. Individual green fluorescent protein-labeled axons can be severed using laser microsurgery and their regrowth followed in vivo. Several neuron types display robust regrowth after injury, including motor and sensory neurons. The small size and transparency of C. elegans make possible large-scale genetic and pharmacological screens for regeneration phenotypes.

Millan MI et al. (2009) Medicina (B Aires) "[The green fluorescent protein that glows in bioscience]."

Millan MI, Becu-Villalobos D

[Medicina (B Aires), 2009]

Green fluorescent protein (GFP) is a protein produced by the jellyfish Aequorea victoria, that emits bioluminescence in the green zone of the visible spectrum. The GFP gene has been cloned and is used in molecular biology as a marker. The three researchers that participated independently in elucidating the structure and function of this and its related proteins, Drs. Shimomura, Chalfie and Tsien were awarded the Nobel Prize in Chemistry 2008. Dr. Shimomura discovered and studied the properties of GFP. Using molecular biological techniques, Chalfie succeeded in introducing the GFP gene into the DNA of the small, almost transparent worm C. elegans, and initiated an era in which GFP would be used as a glowing marker for cellular biology. Finally, Dr.Tsien found precisely how GFP's structure produces the observed green fluorescence, and succeeded in modifying the structure to generate molecules that emit light at slightly different wavelengths, which gave tags of different colors. Fluorescent proteins are very versatile and are being used in many areas, such as microbiology, biotechnology, physiology, environmental engineering, development, etc. They can, for example, illuminate growing cancer tumours; show the development of Alzheimer's disease, or detect arsenic traces in water. Finding the key to how a marine organism produces light unexpectedly ended up providing researchers with a powerful array of tools with which to visualize cell biology in action.

Scholey JM et al. (2004) Biochem Soc Trans "Intraflagellar transport motors in Caenorhabditis elegans neurons."

Scholey JM, Ou G, Gunnarson A, Snow J

[Biochem Soc Trans, 2004]

IFT (intraflagellar transport) assembles and maintains sensory cilia on the dendritic endings of chemosensory neurons within the nematode Caenorhabditis elegans. During IFT, macromolecular protein complexes called IFT particles (which carry ciliary precursors) are moved from the base of the sensory cilium to its distal tip by anterograde IFT motors (kinesin-II and Osm-3 kinesin) and back to the base by retrograde IFT-dynein [Rosenbaum and Witman (2002) Nat. Rev. Mol. Cell Biol. 3, 813-825; Scholey (2003) Annu. Rev. Cell Dev. Biol. 19, 423-443; and Snell, Pan and Wang (2004) Cell 117, 693-697]. In the present study, we describe the protein machinery of IFT in C. elegans, which we have analysed using time-lapse fluorescence microscopy of green fluorescent protein-fusion proteins in concert with ciliary mutants.

Dittman J (2009) Adv Genet "Worm watching: imaging nervous system structure and function in Caenorhabditis elegans."

Dittman J

[Adv Genet, 2009]

Caenorhabditis elegans has become a model system of choice for optical approaches to cellular biology largely due to its extraordinary combination of transparency, well-defined anatomy, rapid generation time, and simple genetics. In particular, studies in nervous system development and function have benefited tremendously since C. elegans was first examined under the microscope. After the introduction of green fluorescent protein as a means of following gene expression and protein localization in living animals, a variety of optical approaches have been developed for probing and perturbing neuronal activity. Microfluidic technologies have opened new possibilities for high-resolution imaging during behavior. Femtosecond pulsed lasers allow for precise severing of individual processes in the living animal. This chapter will cover some recent methodological advances in imaging worm neurons as well as some of the many biological details of the worm nervous system revealed by these new optical approaches. Advantages and limitations of these methods will be discussed in this chapter.

Burnstock G et al. (2009) Acta Physiol (Oxf) "Evolutionary origins of the purinergic signalling system."

Verkhratsky A, Burnstock G

[Acta Physiol (Oxf), 2009]

Purines appear to be the most primitive and widespread chemical messengers in the animal and plant kingdoms. The evidence for purinergic signalling in plants, invertebrates and lower vertebrates is reviewed. Much is based on pharmacological studies, but important recent studies have utilized the techniques of molecular biology and receptors have been cloned and characterized in primitive invertebrates, including the social amoeba Dictyostelium and the platyhelminth Schistosoma, as well as the green algae Ostreococcus, which resemble P2X receptors identified in mammals. This suggests that contrary to earlier speculations, P2X ion channel receptors appeared early in evolution, while G protein-coupled P1 and P2Y receptors were introduced either at the same time or perhaps even later. The absence of gene coding for P2X receptors in some animal groups [e.g. in some insects, roundworms (Caenorhabditis elegans) and the plant Arabidopsis] in contrast to the potent pharmacological actions of nucleotides in the same species, suggests that novel receptors are still to be discovered.

Bamps S et al. (2008) Brief Funct Genomic Proteomic "Large-scale gene expression pattern analysis, in situ, in Caenorhabditis elegans."

Bamps S, Hope IA

[Brief Funct Genomic Proteomic, 2008]

Observation of gene expression in situ provides a direct connection between the genetic information in the genome sequence and the fully determined developmental cell lineage of Caenorhabditis elegans. Green Fluorescent Protein (GFP) reporters have been fused with many C. elegans genes, in large-scale projects, by conventional DNA ligation, PCR stitching, Gateway recombination and recombineering. These reporter gene fusions have then been used in C. elegans transformation either by microinjection or microprojectile bombardment. So far, the developmental distributions of GFP, as driven by the C. elegans DNA to which the reporter gene has been attached, have been determined simply from direct examination of the transgenic strains by epifluorescence microscopy. Automation of GFP expression pattern determination promises improvements in both quality and quantity of this data type, facilitating the handling of such expression pattern data within computer databases. As with the descriptions of the developmental cell lineage and the genome sequence, a complete description of gene expression patterns will provide a vital knowledge framework through which a full understanding of the development of this animal can emerge.

Helmcke KJ et al. (2008) Neurotoxicol Teratol "Utility of Caenorhabditis elegans in high throughput neurotoxicological research."

Avila DS, Helmcke KJ, Aschner M

[Neurotoxicol Teratol, 2008]

Caenorhabditis elegans is a nematode that has been used as a valuable research tool in many facets of biological research. Researchers have used the many tools available to investigate this well-studied nematode, including a cell lineage map, sequenced genome, and complete wiring diagram of the nervous system, making in-depth investigation of the nervous system practical. These tools, along with other advantages, such as its small size, short life cycle, transparency, and ability to generate many progeny, have made C. elegans an attractive model for many studies, including those investigating toxicological paradigms and those using high throughput techniques. Researchers have investigated a number of endpoints, such as behavior and protein expression using a green fluorescent protein (GFP) marker following toxicant exposure and have explored the mechanisms of toxicity using techniques such as microarray, RNA interference (RNAi), and mutagenesis. This review discusses the benefits of using C. elegans as a model system and gives examples of the uses of C. elegans in toxicological research. High throughput techniques are discussed highlighting the advantages of using an in vivo system that has many advantageous characteristics of an in vitro system while emphasizing endpoints relating to developmental and adult neurotoxicity.

Vincensini L et al. (2011) Biol Cell "1001 model organisms to study cilia and flagella."

Vincensini L, Blisnick T, Bastin P

[Biol Cell, 2011]

Most mammalian cell types have the potential to assemble at least one cilium. Immotile cilia participate in numerous sensing processes, while motile cilia are involved in cell motility and movement of extracellular fluid. The functional importance of cilia and flagella is highlighted by the growing list of diseases due to cilia defects. These ciliopathies are marked by an amazing diversity of clinical manifestations and an often complex genetic aetiology. To understand these pathologies, a precise comprehension of the biology of cilia and flagella is required. These organelles are remarkably well conserved throughout eukaryotic evolution. In this review, we describe the strengths of various model organisms to decipher diverse aspects of cilia and flagella biology: molecular composition, mode of assembly, sensing and motility mechanisms and functions. Pioneering studies carried out in the green alga Chlamydomonas established the link between cilia and several genetic diseases. Moreover, multicellular organisms such as mouse, zebrafish, Xenopus, Caenorhabditis elegans or Drosophila, and protists such as Paramecium, Tetrahymena and Trypanosoma or Leishmania each bring specific advantages to the study of cilium biology. For example, the function of genes involved in primary ciliary dyskinesia (due to defects in ciliary motility) can be efficiently assessed in trypanosomes.

Dexter PM et al. (2012) Neurotherapeutics "A predictable worm: application of Caenorhabditis elegans for mechanistic investigation of movement disorders."

Dexter PM, Caldwell KA, Caldwell GA

[Neurotherapeutics, 2012]

Ongoing investigations into causes and cures for human movement disorders are important toward the elucidation of diseases such as Parkinson's disease (PD) and dystonia. The use of animal model systems can provide links to susceptibility factors, as well as therapeutic interventions. In this regard, the nematode roundworm, Caenorhabditis elegans, is ideal for examining age-dependent neurodegenerative disease studies. It is genetically tractable, has a short lifespan, and a well-defined nervous system. Green fluorescent protein is readily visualized in C. elegans because it is a transparent organism, thus the nervous system and factors that alter the viability of neurons can be directly examined in vivo. Through expression of the human PD-associated protein (-synuclein in the worm dopamine neurons), neurodegeneration is observed in an age-dependent manner. Furthermore, expression of the early-onset dystonia-related protein torsinA increases vulnerability to endoplasmic reticulum (ER) stress in C. elegans, because torsinA is located in the ER. Here we provide an overview of collaborative studies we have conducted that collectively demonstrate the usefulness of the nematode model to discern functional effectors of dopaminergic neurodegeneration and ER stress that translate to mammalian data in the fields of PD and dystonia. Taken together, the application of C. elegans toward the evaluation of genetic modifiers for movement disorders research has predictive value and serves to accelerate the path forward for therapeutic interventions.

Gems D et al. (2005) Mechanisms of Ageing & Development "Broad spectrum detoxification: the major longevity assurance process regulated by insulin/IGF-1 signaling?"

Gems D, McElwee JJ

[Mechanisms of Ageing & Development, 2005]

Our recent survey of genes regulated by insulin/IGF-1 signaling (IIS) in Caenorhabditis elegans suggests a role for a number of gene classes in longevity assurance. Based on these findings, we propose a model for the biochemistry of longevity assurance and ageing, which is as follows. Ageing results from molecular damage from highly diverse endobiotic toxins. These are stochastic by-products of diverse metabolic processes, of which reactive oxygen species (ROS) are likely to be only one component. Our microarray analysis suggests a major role in longevity assurance of the phase 1, phase 2 detoxification system involving cytochrome P450 (CYP), short-chain dehydrogenase/ reductase (SDR) and UDP-glucuronosyltransferase (UGT) enzymes. Unlike superoxide and hydrogen peroxide detoxification, this system is energetically costly, and requires the excretion from the cell of its products. Given such costs, its activity may be selected against, as predicted by the disposable soma theory. CYP and UGT enzymes target lipophilic molecular species; insufficient activity of this system is consistent with age-pigment (lipofuscin) accumulation during ageing. We suggest that IIS-regulated longevity assurance involves: (a) energetically costly detoxification and excretion of molecular rubbish, and (b) conservation of existing proteins via molecular chaperones. Given the emphasis in this theory on investment in cellular waste disposal, and on protein conservation, we have dubbed it the green