- Unfolded protein response - Cytosolic
A change in activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a protein that is not folded in its correct three-dimensional structure.
- Sensory perception
The series of events required for an organism to receive a sensory stimulus, convert it to a molecular signal, and recognize and characterize the signal. This is a neurological process.
- Signal transduction
Signal transduction begins with a stimulating event, such as a ligand binding to a receptor on the surface of the cell, and is followed by intracellular signaling steps that eventually trigger a response. In many cases the end response is modification of the regulation of gene transcription, but could also be the regulation of a metabolic process.
- Thermotaxis
The directed movement of an organism in response to a temperature gradient. Movement may be towards either a higher or lower temperature.
- Hormesis
The process whereby a low exposure to a toxin or stressor produces a generally positive response in the animal that is the opposite effect produced in response to a higher exposure. This can be observed in cases where C. elegans is exposed to short doses of temperature stress during development. Under such limited exposures, animals exhibit a longer life span than animals reared at room temperature. However, extended exposure to thermal stress results in severely shortened lifespans.
- Male sexual development
The establishment of the sex of a male organism by physical and physiological differentiation through sex-specific developmental pathways leading to a fully fertile male of the species.
- Adaptation
Adaptation occurs when a stimulus that once elicited a particular response, now elicits the opposite reaction. In C. elegans, this behavior has been shown through chemotaxis studies where extended exposure to an odor in the absence of food will result in a suppression of the chemotaxis response. In addition, by coupling an attractive stimulus to a starvation environment, the once attractive chemical is responded to as a repellent. However, these adaptations can be restored by brief exposure to the stimulus in the presence of food.
- Response to toxicity
Exposure to a toxic substance can activate any number of processes that result in a change in state or activity of the organism. As a soil dwelling organism, C. elegans has evolved defenses against damaging substances in the soil environment and as such has proved to be an ideal organism for studying biological responses to toxins. These responses can occur at an organism level, such as invoking an avoidance behavior, or on a cellular level, such as activation of a cellular stress response. Cellular defenses have been shown to be invoked in response to reactive oxygen species, heavy metals, and toxin-induced unfolded proteins.
- Molting
Under good conditions, C. elegans enters and exits four larval stages before becoming a fertile adult. Each developmental stage is punctuated with a molt that entails the shedding of the larval cuticle and the generation of a completely new one. It has been shown that each cuticle is unique in its composition. Molting is a carefully timed process that needs to be coordinated with development, new cuticle synthesis, and cuticle shedding. Mutations in a set of genes called heterochronic genes regulates the timing development and the molts and result in precocious or retarded development of parts of the animals that aren't synchronized with the animals' life stage.