agarose-microchambers-for-long-term-calcium-imaging-caenorhabditis

Agarose Microchambers for Long-term Calcium Imaging of <em>Caenorhabditis elegans</em>

Behavior is controlled by the nervous system. Calcium imaging is a straightforward method in the transparent nematode Caenorhabditis elegans to measure ...

Max Planck Institute for Biophysical Chemistry

Comamonas testosteroni Pb50 is a microorganism that possesses high tolerance for phenol and shows strong phenol degrading activity. This bacterial strain is capable of utilizing phenol as the sole carbon and energy source. Although examples are known in which the C. testosteroni utilizes phenol for growth or metabolism, much less information are known on the nature of the phenol-oxidizing enzymes in this microorganism. Therefore, the occurrence and cellular location of phenol hydroxylase (EC 1.14.13.7), the enzyme participating in the first step of phenol degradation, catalyzing its hydroxylation to catechol in a bacterial Comamonas testosteroni Pb50 strain grown in the presence of phenol as a sole carbon and energy source are the aims of this study.

Isolation and partial characterization of extracellular NADPH-dependent phenol hydroxylase oxidizing phenol to catechol in Comamonas testosteroni.

The effective dissolution of calcium oxalate, the main component of kidney stones, is important in the treatment of nephrolithisis. Polyphenol glycosides constitute compounds supporting dissolution and inhibition of formation of stones. These moieties possess oxygen atoms which can interact with calcium cations. Density functional theory studies of interactions of polyphenol glycosides and Ca(2+) were performed to determine preferred structures and the role of polyphenol and carbohydrate parts in the formation of complexes. The determination of these properties may be useful in designing new complexes, effectively interacting with calcium compounds. In the present study we try to define factors influencing interaction energies and stabilization. The determined structures were divided according to coordination numbers. Obtained data indicate that for stronger interactions complexes maximize the number of O-Ca(2+) contacts.

Theoretical studies of structure, energetics and properties of Ca²⁺ complexes with alizarin glucoside.

Sleep is an essential behavior that is found in all animals that have a nervous system. Neural activity is thought to control sleep, but little is known about the identity and the function of neural circuits underlying sleep. Lethargus is a developmentally regulated period of behavioral quiescence in C. elegans larvae that has sleep-like properties.

An AP2 transcription factor is required for a sleep-active neuron to induce sleep-like quiescence in C. elegans.

During their development, Caenorhabditis elegans larvae go through four developmental stages. At the end of each larval stage, nematodes molt. They synthesize a new cuticle and shed the old cuticle. During the molt, larvae display a sleep-like behavior that is called lethargus. We wanted to determine how gene expression changes during the C. elegans molting cycle. We performed transcriptional profiling of C. elegans by selecting larvae displaying either sleep-like behavior during the molt or wake behavior during the intermolt to identify genes that oscillate with the molting-cycle. We found that expression changed during the molt and we identified 520 genes that oscillated with the molting cycle. 138 of these genes were not previously reported to oscillate. The majority of genes that had oscillating expression levels appear to be involved in molting, indicating that the majority of transcriptional changes serve to resynthesize the cuticle. Identification of genes that control sleep-like behavior during lethargus is difficult but may be possible by looking at genes that are expressed in neurons. 22 of the oscillating genes were expressed in neurons. One of these genes, the dopamine transporter gene dat-1, was previously shown in mammals and in C. elegans to control sleep. Taken together, we provide a dataset of genes that oscillate with the molting and sleep-wake cycle, which will be useful to investigate molting and possibly also sleep-like behavior during lethargus.

Michal Turek

Max Planck Institute for Biophysical Chemistry

Agarose Microchambers for Long-term Calcium Imaging of Caenorhabditis elegans