-
[
International Worm Meeting,
2005]
Medical students are often fascinated with the nervous system and with organismal impacts of its dynamics and destruction. The study of molecular cues underlying phenomena such as axonal migration, if properly explored, could catch the students motivation and commitment to learn biochemistry. C. elegans is a suitable, low cost, laboratory model to let moderately skilled students explore the consequences of molecular events at the whole organism level. This work reports on the use of C. elegans to introduce 2nd year medical students to the deleterious effects of gene Knockouts upon response of neurons to extracellular biochemical cues. The main goals of this learning activity were for the students to (1) understand at a basic level the mechanisms of axon guidance and (2) propose possible applications for the usage of knowledge on axon guidance molecules in the treatment of medical pathologies. We divided the activity in three moments. First, students performed behavioral assays to detect movement alterations in C. elegans mutants lacking specific axon guidance molecules. At this moment, students were not aware which genes were mutated. Microscopy observation of abnormal axonal migration patterns of dorsal and ventral cord neurons was also performed. For optimal visualization of neurons, these mutants had been crossed with a pan-neuronal GFP expression strain (Unc-119::GFP). Identification of the specific gene mutated in each strain was then provided to students: Unc-6; Unc-5 and Unc-40. The students were asked to relate abnormal patterns in axon migration/nerve formation with the absent molecular components and the phenotype of mutant strains. Analysis and discussion of a review article about extracellular guidance cues allowed students to further acquire background and consolidate knowledge on this topic (Dynamic regulation of axon guidance. Yu T.W. and Bargmann C.I.; 2001; Nature Neuroscience 4:1169-1176). Finally, students proposed some clinical applications of the recent knowledge concerning the molecular guidance cues and their role in neuronal migration.
-
[
European Worm Meeting,
2002]
Cilia are evolutionarily conserved subcellular organelles functioning in cell motility, movement of extracellular fluids, sensory perception (e.g. smell) and determination of left-right asymmetry. While a great deal is known about the structure, function and motility of cilia, very little is known about the molecular mechanisms that regulate ciliogenesis in a cell-type specific and developmental manner. How do cilia become functional? How can they do what they do?
-
[
Cell Host Microbe,
2022]
Caenorhabditis elegans do not grow on either Staphylococcus saprophyticus or heat-killed Escherichia coli, but do so when exposed to both. In this issue of Cell Host & Microbe, Geng and colleagues have identified E.coli-derived signals as well as the host's neural and innate immunity pathways that promote digestion of S.saprophyticus.
-
[
Nat Methods,
2008]
We describe an automated method to isolate mutant Caenorhabditis elegans that do not appropriately execute cellular differentiation programs. We used a fluorescence-activated sorting mechanism implemented in the COPAS Biosort machine to isolate mutants with subtle alterations in the cellular specificity of GFP expression. This methodology is considerably more efficient than comparable manual screens and enabled us to isolate mutants in which dopamine neurons do not differentiate appropriately.
-
[
Curr Biol,
2010]
Why do many microRNA gene mutants display no evident phenotype? Multiply mutant worms that are selectively impaired in genetic regulatory network activities have been used to uncover previously unknown functions for numerous Caenorhabditis elegans microRNAs.
-
[
Curr Biol,
2006]
A left-right asymmetry in neuronal function is specified surprisingly early during embryogenesis in Caenorhabditis elegans. Do early cues influence left-right asymmetries in other animals? How are early cues remembered until late in development?
-
[
Curr Biol,
2000]
Recent studies of vulva development in the nematode Pristionchus pacificus have identified cell interactions that do not appear to occur in Caenorhabditis elegans, The new results underscore the diversity of patterning mechanisms that can produce structures with similar cellular morphology.
-
[
Kisaengchunghak Chapchi,
1966]
The clinical manifestations in filarial infection were examined during 1965-1966 from the known endemic areas: Yongju, a mountainous inland area and Cheju-Do, an island. 1. All the microfilaria which were found during the survey were Brugia malayi. 2. The principal symptom was cuticular hypertrophy (elephantiasis). It was found in 4 cases from Yongju among 707 villagers, 84 cases from Cheju-Do among 2,376 villagers. 3. Four microfilaremia cases (4.5%) were found among a total of 88 cases of elephantiasis. 4. In Cheju-Do, the higher incidence of elephantiasis was observed among people over 20 years old and the females showed much higher incidence than males (30 males and 54 females). 5. The cuticular hypertrophic changes (elephantiasis) appeared more often in the lower extremities(77%) than in the upper part of the body, and in the right side than in the left.
-
[
Curr Biol,
2001]
How do animal tissues resist the shearing forces to which they are exposed during locomotion or harsh encounters with the environment? Genetic analysis in Caenorhabditis elegans is furthering our understanding of the nature and function of the attachments that preserve tissue integrity.
-
[
Cold Spring Harb Symp Quant Biol,
1982]
Microtubules (MTs) are ubiquitous components of neuronal processes, and although they have been implicated in neurite outgrowth, shape maintenance, axonal transport, and sensory transduction, their function remains unclear. The MTs in the neurons of the nematode Caenorhabditis elegans have unusual structures that permit a comparative approach to the relationship of microtubule structure and function. A set of six touch-receptor neurons (the microtubule cells) contain prominent arrays of large MTs. These MTs have more protofilaments than do MTs in other neurons (15 as opposed to 11), and they respond differently to antimicrotubule drugs, fixation protocols, temperature, and mutation. Studies of C. elegans neurotubules suggest that most MT functions do not require long, continuous MTs or MTs with a specific number of protofilaments. Some functions, however, such as the sensory transduction of the microtubule cells, do require a specific microtubule substructure. A review of these data is presented in this