Chemical basis of microbiome preference in the nematode C. elegans.

Animals are exposed to many microbes in their environment, some of which have been shown to colonize various tissues including the intestine. The composition of the intestinal microbiota affects many aspects of the host's physiology and health. Despite this, very little is known about whether host behavior contributes to the colonization.

The nematode worm chooses between bacterial foods as if maximizing economic utility.

In value-based decision making, options are selected according to subjective values assigned by the individual to available goods and actions. Despite the importance of this faculty of the mind, the neural mechanisms of value assignments, and how choices are directed by them, remain obscure. To investigate this problem, we used a classic measure of utility maximization, the Generalized Axiom of Revealed Preference, to quantify internal consistency of food preferences in , a nematode worm with a nervous system of only 302 neurons.

The Basics of Setting up Successful Teaching Labs and Short-Term Projects with C. elegans.

Caenorhabditis elegans is an excellent organism for teaching or doing short-term research projects because of the many freely-available comprehensive resources describing its genome and biology, its short-generation time and the ease of working with it in the lab. However, it can be daunting to begin a short-term project or a teaching lab with an organism with which one has little or no experience. Therefore, in this article, we will discuss the minimal equipment, reagents, and protocols needed to begin doing experiments with C.

Using Optogenetics to Understand Neuronal Mechanisms Underlying Behavior in .

Approaches for inhibiting and activating neurons are essential for understanding how neurons and neuronal circuits produce behavior. Optogenetics is a recently-developed technique which uses light to manipulate neuronal activity with temporal precision in behaving animals and is widely-used by neuroscience researchers Optogenetics is also an excellent method to incorporate into an undergraduate neuroscience laboratory module because students can learn to conduct and analyze quantitative behavioral assays, reinforce their understanding of synaptic transmission, and investigate the genetic and neuronal basis of behavior. Here, we describe a module in which students use light to activate serotonergic neurons expressing the light-activated ion channel channelrhodopsin in wildtype and mutant , and observe and analyze the effects on the movement behavior of the nematode.

Identification of attractive odorants released by preferred bacterial food found in the natural habitats of C. elegans.

Food choice is critical for survival because organisms must choose food that is edible and nutritious and avoid pathogenic food. Many organisms, including the nematode C. elegans, use olfaction to detect and distinguish among food sources.

Identification of Odor Blend Used by Caenorhabditis elegans for Pathogen Recognition.

Animals have evolved specialized pathways to detect appropriate food sources and avoid harmful ones. Caenorhabditis elegans can distinguish among the odors of various species of bacteria, its major food source, but little is known about what specific chemical cue or combination of chemical cues C. elegans uses to detect and recognize different microbes.

Multigenic natural variation underlies Caenorhabditis elegans olfactory preference for the bacterial pathogen Serratia marcescens.

The nematode Caenorhabditis elegans can use olfaction to discriminate among different kinds of bacteria, its major food source. We asked how natural genetic variation contributes to choice behavior, focusing on differences in olfactory preference behavior between two wild-type C. elegans strains.

Axonal transport of mitochondria requires milton to recruit kinesin heavy chain and is light chain independent.

Mitochondria are distributed within cells to match local energy demands. We report that the microtubule-dependent transport of mitochondria depends on the ability of milton to act as an adaptor protein that can recruit the heavy chain of conventional kinesin-1 (kinesin heavy chain [KHC]) to mitochondria. Biochemical and genetic evidence demonstrate that kinesin recruitment and mitochondrial transport are independent of kinesin light chain (KLC); KLC antagonizes milton's association with KHC and is absent from milton-KHC complexes, and mitochondria are present in klc (-/-) photoreceptor axons.