Male mating behavior

Author: Barr, M. M., Garcia, L. R. Description: Caenorhabditis elegans male mating provides an excellent opportunity to determine how sensory perception regulates behavior and motor programs. The male-specific nervous system and muscles are superimposed over the general nervous system and musculature. Genetic screens and genomic approaches have identified male-specific and male-enriched genes as well as non-sex specific molecules specialized for mating sub-behaviors. In this chapter, we discuss the cellular, genetic, and molecular basis for male mating behavior. Subject headings: Animals; Caenorhabditis elegans/anatomy & histology; Caenorhabditis elegans/physiology; Ejaculation; Female; Male; Sex…

See more and a link to full text

Neural regulation of thermotaxis in Caenorhabditis elegans

Author: Mori, I.; Ohshima, Y. Description: Thermal stimulus is an important environmental factor influencing animal behavior. However, the mechanisms underlying thermosensation and thermal adaptation are poorly understood. The nematode Caenorhabditis elegans can sense a range of environmental temperatures and migrate towards the cultivation temperature on a thermal gradient. This modifiable thermotactic response provides an ideal system for studying the cellular and molecular processes involved in thermosensation and thermal information storage. We have identified neurons critical for thermotaxis by killing individual cells in live animals. The results indicate that an amphid…

See more and a link to full text

Quantitative measures of aging in the nematode Caenorhabditis elegans. I. Population and longitudinal studies of two behavioral parameters

Author: Bolanowski, M.A.; Russell, R.L.; Jacobson, L.A. Description: As a first step in the quantitative characterization of senescence in the nematode Caenorhabditis elegans, we have studied movement wave frequency, defecation frequency, and whole-body water efflux as a function of age. Populations of C. elegans, strain N2, were cultured monoxenically on E. coli lawns at 20 degrees C. The median lifespan in such populations was approximately 12 days. Population mean movement wave frequency declined linearly with age (slope = -4.66 waves/minute per day). The decline in population mean defecation frequency (defecations…

See more and a link to full text

A diacylglycerol kinase modulates long-term thermotactic behavioral plasticity in C. elegans

Author: Biron, D.; Shibuya, M.; Gabel, C.; Wasserman, S.M.; Clark, D.A.; Brown, A.; Sengupta, P.; Samuel, A.D.T. Description: A memory of prior thermal experience governs Caenorhabditis elegans thermotactic behavior. On a spatial thermal gradient, C. elegans tracks isotherms near a remembered temperature we call the thermotactic set-point (T(S)). The T(S) corresponds to the previous cultivation temperature and can be reset by sustained exposure to a new temperature. The mechanisms underlying this behavioral plasticity are unknown, partly because sensory and experience-dependent components of thermotactic behavior have been difficult to separate. Using…

See more and a link to full text

Genetic analysis of IP3 and calcium signalling pathways in C. elegans

Author: Baylis, H.A.; Vazquez-Manrique, R.P. Description: BACKGROUND: The nematode, Caenorhabditis elegans, is an established model system that is particularly well suited to genetic analysis. C. elegans is easily manipulated and we have an in depth knowledge of many aspects of its biology. Thus, it is an attractive system in which to pursue integrated studies of signalling pathways. C. elegans has a complement of calcium signalling molecules similar to that of other animals. SCOPE OF REVIEW: We focus on IP3 signalling. We describe how forward and reverse genetic approaches, including RNAi,…

See more and a link to full text

Glucose shortens the life span of C. elegans by downregulating DAF-16/FOXO activity and aquaporin gene expression

Author: Lee, S.-J., Murphy, C. T., & Kenyon, C. Description: Many studies have addressed the effect of dietary glycemic index on obesity and diabetes, but little is known about its effect on life span itself. We found that adding a small amount of glucose to the medium (2%) shortened the life span of C. elegans by inhibiting the activities of life span-extending transcription factors that are also inhibited by insulin signaling: the FOXO family member DAF-16 and the heat shock factor HSF-1. This effect involved the downregulation of an aquaporin…

See more and a link to full text

Inositol 1,4,5-trisphosphate receptors are strongly expressed in the nervous system, pharynx, intestine, gonad and excretory cell of Caenorhabditis elegans and are encoded by a single gene (itr-1)

Author: Baylis, H.A.; Furuichi, T.; Yoshikawa, F.; Mikoshiba, K.; Sattelle, D.B. Description: Inositol 1,4,5-trisphosphate (InsP3) activates receptors (InsP3Rs) that mediate intracellular Ca(2+ )release, thereby modulating intracellular calcium signals and regulating important aspects of cellular physiology and gene expression. To further our understanding of InsP3Rs we have characterised InsP3Rs and the InsP3R gene, itr-1, from the model organism Caenorhabditis elegans. cDNAs encoding InsP3Rs were cloned enabling us to: (a) identify three putative transcription start sites that result in alternative mRNA 5′ ends: (b) detect alternative splicing at three sites and: (c)…

See more and a link to full text

A comparative study of siderophore production by fungi from marine and terrestrial habitats

Author: Baakza, A.; Vala, A.K.; Dave, B.P.; Dube, H.C. Description: Siderophore producing potential of 20 fungal isolates (same 10 species from each marine and terrestrial habitat) were examined and compared. Except marine Aspergillus flavus, all isolates produced siderophores as evidenced by positive reaction in FeCl3 test, CAS assay and CAS agar plate test. The results indicated widespread occurrence of siderophores in both the habitats. Examination of the chemical nature of siderophores revealed that mucoraceous fungi produced carboxylate, while others produced hydroxamate siderophores. Thus, the nature of siderophore was found to…

See more and a link to full text

Thermal preference of Caenorhabditis elegans: a null model and empirical tests

Author: Anderson, J.L.; Albergotti, L.; Proulx, S.; Peden, C.; Huey, R.B.; Phillips, P.C. Description: The preferred body temperature of ectotherms is typically inferred from the observed distribution of body temperatures in a laboratory thermal gradient. For very small organisms, however, that observed distribution might misrepresent true thermal preferences. Tiny ectotherms have limited thermal inertia, and so their body temperature and speed of movement will vary with their position along the gradient. In order to separate the direct effects of body temperature on movement from actual preference behavior on a thermal…

See more and a link to full text

Does thermoregulatory behavior maximize reproductive fitness of natural isolates of Caenorhabditis elegans?

Author: Anderson, J.L.; Albergotti, L.; Ellebracht, B.; Huey, R.B.; Phillips, P.C. Description: BACKGROUND: A central premise of physiological ecology is that an animal’s preferred body temperature should correspond closely with the temperature maximizing performance and Darwinian fitness. Testing this co-adaptational hypothesis has been problematic for several reasons. First, reproductive fitness is the appropriate measure, but is difficult to measure in most animals. Second, no single fitness measure applies to all demographic situations, complicating interpretations. Here we test the co-adaptation hypothesis by studying an organism (Caenorhabditis elegans) in which both fitness…

See more and a link to full text