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[
2008]
"The pine wood nematode (PWN), Bursaphelenchus xylophilus, is a mycophagous and phytophagous pathogen responsible for the current widespread epidemic of pine wilt disease, which has become a major threat to pine forests and a socioeconomic burden in Eastern Asia, North America, and some parts of Europe. No therapeutic drug for eradication of PWN currently exists. In addition, although several preventive chemical agents are currently available (e.g., morantel tartarate, avermectin, emamectin benzoate), each is associated with drawbacks (e.g., poor water solubility, efficacy, and specificity) that limit their use as of trunk-injection agents against PWN. Ideal trunk-injection drugs against PWN would be highly water-soluble and possess both nematocidal and antifungal activity (against blue stain fungi, the food source of PWN). To search for such a multifunctional nematocidal agent, we first established a high-throughput screening method, which yields potential hits within 6 hours. Using this high-throughput method, we screened of a large set of antifungal chemical libraries for agents with antinematodal activity. Among the compounds identified was HWY-4213 (1-n-undecyl-2-(2-fluorphenyl)methyl-3,4-dihydro-6,7-dimethoxy-isoquinolinium chloride), a water-soluble agent that exhibited potent antifungal and nematocidal activity. The potent nematocidal activity of this compound was confirmed with cotton ball assays. Further development of HWY-4213 as a therapeutic and preventive trunk injection agent against PWN is warranted. (Supported by a grant from a Forest Science & Technology Project [No. S110707L0501501 to YKP] through the Korea Forest Service)"
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[
International Worm Meeting,
2017]
Artificial light at night (ALAN) has many broad-scale and global implications for ecosystems and wildlife that have evolved under a 24-h circadian cycle. With increased urbanization, artificial light at night has directly altered natural photoperiods and nocturnal light intensity. Artificial light at night can disrupt behavioral patterns such as foraging activity and mating in animals. Disturbances in natural light and dark cycles also affect melatonin-regulated circadian and seasonal rhythms in Drosophila. We investigated the impact of ecologically relevant levels of light pollution on an important invertebrate model, Caenorhabditis elegans, as the impact of night lighting at these light levels is currently unknown. In this study, we exposed worms to artificial light at four intensities: 10-4 lx (control, comparable to natural nocturnal darkness), 10-2 lx (comparable to full-moon lighting and a low level of light pollution), 1 lx (comparable to dawn/dusk or intense light pollution), and 100 lx (dim daylight level comparable to extreme light pollution) on a 12L:12D photoperiod (100 lx treatments experienced constant light). We measured the impact of these light treatments on offspring production in hermaphroditic C. elegans. We grew worms for 2 generations in each light treatment, and then recorded the lifespan and counted the number of hatched offspring produced in the F3 generation. Our data show no significant differences among light levels for lifespan or offspring production suggesting that at least for these life history traits, ALAN does not affect these soil nematodes. Future directions include measuring additional life history traits and circadian gene expression for worms exposed to ALAN.
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[
International Worm Meeting,
2007]
Multi-generational growth will be essential for any hope of long term human colonization of the cosmos. However, there is a lack of information about any species in space beyond three generations. In addition, trips to the Moon or Mars will result in greater exposure to space radiation, although little is known about cumulative biological effects. C. elegans provides a simple model system in which to study multi-generational growth and radiation exposure in space. Cultures of C. elegans (wt CC1 and balancer eT1 strains) were maintained on-board the ISS for periods well in excess of 3 months. Worms were grown through 10+ generations on the ISS using an automated culturing system employing defined liquid medium, commercial growth chambers, peristaltic pumps to passage worms and control instrumentation. The culturing system, the C. elegans Habitat, was housed in a temperature controlled incubator located in the ISS module Destiny. Integrated video cameras with micro lenses, combined with data downlink, were utilized to image worms for real-time assessment of larval stages, population density and movement behavior. Data analysis was performed by students at 35+ middle and high schools across the United States, Canada and Malaysia, allowing students to learn about the benefits of C. elegans research while gaining experience in the scientific method. While preliminary, data confirm what was inferred from past shorter duration spaceflight missions: growth, development, and behavior of worms are grossly unaltered during spaceflight. Changes in worm muscle that were previously observed (decreased myosin heavy chain and MyoD expression, movement defect) may reflect adaptive changes in muscle in space or may be artifacts of past culturing techniques. Planned post-flight analyses should distinguish these two possibilities. Post flight analysis of eT1 worms will determine if increased rates of genetic mutation occur with long-term exposure to space radiation. Further insights should be gained into radiation concerns for future planned interplanetary human exploration missions. In conclusion, there is no major gravity-dependent process associated with spaceflight that precludes essentially normal animal growth and development for at least ten generations in C. elegans. This work was sponsored by the National Space Agency of Malaysia (ANGKASA).