-
Mendoza, S., Du, A., Tan, T., Madruga, B., Yamada, A., David, A.R., Huang, R., Mai, P., Thatcher, J., Jin, S., D'Orazio, E.G., Watson, S., Carmona, J., Arisaka, K.
[
International Worm Meeting,
2017]
Various model organisms allow researchers to draw valuable insights into larger complexities of the natural world. With a relatively simple nervous system consisting of only 302 neurons, stereotyped motor behavior, and method of cultivation, the nematode Caenorhabditis elegans is an ideal model organism to study neuroscience and biophysics. The Elegant Mind Club at UCLA seeks to study this simple yet behaviorally insightful organism to provide undergraduate students across STEM disciplines the unique opportunity to design their own research methods and carry out experiments in a laboratory setting, allowing them to explore the nature of scientific research. Students are tasked with ensuring specimen propagation, as well as with assembling their own experimental hardware. Additionally, undergraduates gain hands-on experience working with and helping design a collection of state-of-the-art in-house microscopes. Sole responsibility for biological sample quality teaches students the discipline associated with handling chemicals and maintaining sterility. Peer-reviewed publications and online resources associated with the prolific C. elegans community, such as WormBook, WormAtlas, and the Caenorhabditis Genetics Center, provide students with method reference. Today, systems for thermotaxis, electrotaxis, phototaxis, magnetotaxis and free motion have been reproduced from literature and embellished by our members to conduct novel research on the behavioral and neuronal level. Our lab was founded by a few core members and has now expanded to host over 50 students from universities across the world. We hope to instill students with a fervor for pursuing scientific discovery.
-
[
West Coast Worm Meeting,
2002]
Polarization of the C. elegans zygote depends on cortically enriched proteins (e.g. the evolutionarily conserved PARs) and two cytoplasmic proteins (MEX-5/6) that function together to localize cytoplasmic determinants (e.g. PIE-1) in response to a polarity cue associated with the sperm asters.
-
In recent years a number of different techniques have been developed to fuse cells of various origin in order to obtain hybrids with qualities different from each of the original cells. In many cases, one wants to fuse large numbers of cells (e.g. to generate hybridomas), and fusion occurs more or less randomly (e.g. Kohler and Milstein, 1975). With other methods, individual cells have been fused under controlled conditions (e.g., McGrath and Solter, 1984). So far a prerequisite for fusing two preselected cells has been that they must be isolated away
-
[
Ageing Res Rev,
2024]
This paper addresses how long lifespan can be extended via multiple interventions, such as dietary supplements [e.g., curcumin, resveratrol, sulforaphane, complex phytochemical mixtures (e.g., Moringa, Rhodiola)], pharmaceutical agents (e.g., metformin), caloric restriction, intermittent fasting, exercise and other activities. This evaluation was framed within the context of hormesis, a biphasic dose response with specific quantitative features describing the limits of biological/phenotypic plasticity for integrative biological endpoints (e.g., cell proliferation, memory, fecundity, growth, tissue repair, stem cell population expansion/differentiation, longevity). Evaluation of several hundred lifespan extending agents using yeast, nematode (Caenorhabditis elegans), multiple insect and other invertebrate and vertebrate models (e.g., fish, rodents), revealed they responded in a manner [average (mean/median) and maximum lifespans] consistent with the quantitative features [i.e., 30-60% greater at maximum (Hormesis Rule)] of the hormetic dose response. These lifespan extension features were independent of biological model, inducing agent, endpoints measured and mechanism. These findings indicate that hormesis describes the capacity to extend life via numerous agents and activities and that the magnitude of lifespan extension is modest, in the percentage, not fold, range. These findings have important implications for human aging, genetic diseases/environmental stresses and lifespan extension, as well as public health practices and long-term societal resource planning.
-
[
International Worm Meeting,
2011]
The coevolution between host and parasite is believed to be associated with high evolutionary dynamics affecting various life-history characteristics and the underlying genetics. We use experimental evolution between the nematode host Caenorhabditis elegans and its microparasite Bacillus thuringiensis to explore the consequences of coevolution. Our current results demonstrate that B. thuringiensis evolves into two very distinct phenotypes in response to either coevolution with the host (e.g., maintenance of virulence, no biofilm production) or evolution in the absence of an antagonist (e.g., loss of virulence, pronounced biofilm production). The host C. elegans shows similar although less pronounced adaptations (e.g., increased resistance, reduced body size). Based on genomic analyses, we are currently exploring the underlying molecular genetics. Our study provides experimental evidence for the high selective dynamics that result from host-parasite coevolution.
-
[
Free Radic Biol Med,
2002]
The nematode Caenorhabditis elegans has proven a robust genetic model for studies of aging, including the roles of oxidative stress and protein damage. In this review, we focus on the genetics of select long-lived (e.g.,
age-1,
daf-2,
daf-16) and short-lived (e.g.,
mev-1) mutants that have proven useful in revealing the relationships that exist among oxidative stress, life span, and protein oxidation. The former are known to control an insulin/IGF-1-like pathway in C. elegans, while the latter affect mitochondrial function.
-
Mai, P., D'Orazio, E.G., Raghute, R., Carmona, J., Jin, S., Mendoza, S., Arisaka, K., Shrestha, A.
[
International Worm Meeting,
2017]
Research has shown that Caenorhabditis elegans demonstrates a highly deterministic behavioral response under an electric field; Under such conditions, worms migrate to the negative pole of the field, coupled with an angular offset proportional to the absolute strength of the field. Under relatively large applied voltages (12 V/cm ) worms migrate to the field's negative pole with a larger opening angle, as compared to a more modest 5 V/cm. While this relatively broad observation is interesting in itself, a more comprehensive motional attractor analysis is yet to be conducted on C. elegans demonstrating electrotactic responses. To address this, we experimentally observed the motion of ten C. elegans on 2% agarose under electric fields varying from 5 - 12 V/cm. A custom built worm-tracking microscope was implemented for these purposes in order to accurately record the worm's body configuration and absolute position during trials. MatLab fitting software was written and used to analytically describe the worm's motion under experimental and controlled conditions. In the absence of an electric field, the motion of C. elegans may be well-modeled as a propagating sinusoid, fit along the entirety of the worm's body. However, under the application of an electric field, the sinusoidal fit requires a damping term to fully represent an apparent partial paralyzation of the worm's posterior half. This result suggests the possibility that the presence of an electric field likely inhibits specific motor neurons responsible for the muscular control of the posterior regions of the worm's body.
-
[
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.
-
[
J Hazard Mater,
2019]
Increasing concerns are earned on the multigenerational hazards of antibiotics due to the connection between their mother-children transfer via cord blood and breast milk and obesity in the children. Currently, Caenorhabditis elegans was exposed to sulfamethoxazole (SMX) over 11 generations (F0-F10). Indicators of obesogenic effects and gene expressions were measured in each generation and also in T11 to T13 that were the offspring of F10. Biochemical analysis results showed that SMX stimulated fatty acids in most generations including T13. The stimulation was resulted from the balance between enzymes for fatty acid synthesis (e.g., fatty acid synthetase) and those for its consumption (e.g., fatty acid transport protein). Gene expression analysis demonstrated that the obesogenic effects of SMX involved peroxisome proliferator activated receptors (PPARs, e.g.,
nhr-49) and insulin/insulin-like signaling (IIS) pathways (e.g.,
ins-1,
daf-2 and
daf-16). Further epigenetic analysis demonstrated that SMX caused 3-fold more H3K4me3 binding genes than the control in F10 and T13. In F10, the most significantly activated genes were in metabolic and biosynthetic processes of various lipids, nervous system and development. The different gene expressions in T13 from those in F10 involved development, growth, reproduction and responses to chemicals in addition to metabolic processes.
-
[
Curr Opin Neurobiol,
1998]
Ion channels in the amiloride-sensitive Na+ channel/degenerin (NaC/DEG) family of cation channels have very diverse functions. They can be constitutively active (e.g. the epithelial Na+ channel), gated by a ligand (e.g. the peptide-gated channel FaNaC or H+-gated cation channels [ASICs]) or possibly activated by stretch (degenerins of Caenorhabditis elegans). Despite this functional diversity, the heterologous expressed channels share the following properties: permeability to Na+, inhibition by the diuretic amiloride and no voltage gating. This review will focus on recent advances in this ion channel family, with special emphasis on H+-gated cation channels.