Xenopus properties

The lateral diverticulum cells in semi-terrestrial species such as toads can still detect a wide range of amino acids, comparable to the properties of fish neuroepithelium. Both water-soluble and volatile odourants are discriminated by the olfactory neurones of the Clawed toad (Xenopus) (Iida and Kashiwayanagi, 1999). When single olfactory neurones were tested with acidic, neutral and basic amino acids, over 50% of the receptors gave some excitatory response. 

Characterization of the properties of LGIC receptors expressed in Xenopus oocytes has heen facihtated hy the variety of studies that can be carried out on recombinant receptors in this system. 

Using optical traps, Cui and Bustamante [76] stretched isolated chicken erythrocyte fibers, and Bennink et al. [77] pulled on fibers directly reconstituted in the flow cell from X-DNA and purified histones with the help of Xenopus extracts (see Fig. 10a for a schematic of the latter experiment). Up to 20 pN, the fibers underwent reversible stretching, but applying stretching forces above 20 pN led to irreversible alterations, interpreted in terms of removal of histone octamers from the fibers with recovery of the mechanical properties of naked DNA. 

Thomson, F.J. Moyes, C. Scott, P.H. Plevin, R. Gould, G.W. Lysopho-sphatidic acid stimulates glucose transport in Xenopus oocytes via a phosphatidylinositol 3 -kinase with distinct properties. Biochem. J., 316, 161-166 (1996)... 

Koch, B. D., Sangameswaran, L., Dietrich, P., Delgado, S. G., Fish, L. M., Herman, R. C., Hunter, J. C. Electrophysiological properties of rat homologs of SCN9A and SCN10A sodium channels expressed in Xenopus oocytes, Biophysical. J. 1997, 72, A116. 

The unique structural characteristics of these variant schistosome P subunits appear to be further reflected in their unusual functional properties (Kohn et ai, 2001a). As discussed, conventional P subunits enhance currents through a, subunits. In contrast, co-expression of these variant P subunits in Xenopus oocytes with either a jellyfish (CyCav1) or human (Ca. 3) a, subunit results in a dramatic reduction in current. Other than this anomalous effect... 

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