Xenopus laevis

Ca waves in systems [ike Xenopus laevis oocytes and pancreatic (3 cells fall into this category Electrochemical waves in cardiac and nerve tissue have this origin and the appearance and/or breakup of spiral wave patterns in excitable media are believed to be responsible for various types of arrhythmias in the heart [39, 40]. Figure C3.6.9 shows an excitable spiral wave in dog epicardial muscle [41]. 

Frog metamorphosis assay rate of tail resorption in Xenopus laevis. 

There is some evidence for chemically mediated endocrine disruption in amphibians. The egg yolk protein, vitellogenin, is inducible in amphibians by exposure to DDT. " Males of the short clawed toad Xenopus laevis given 250 fig/g or 1 fig/g o,p -DDT for seven days have been shown to produce vitellogenin, although the induction was less than that achieved by treatment with 1 fig/g of either 17/1-oestradiol or diethylstilboestrol. Research has also shown that endocrine disrupting chemicals can alter sex ratios in wild populations of certain species PCB congeners and organochlorine compounds have been linked with male domination of sex ratios in polluted compared to unpolluted sites. ... 

FIGURE 2.11 Receptor-occupancy curves for activation of human calcitonin type 2 receptors by the agonist human calcitonin. Ordinates (response as a fraction of the maximal response to human calcitonin). Abscissae (fractional receptor occupancy by human calcitonin). Curves shown for receptors transfected into three cell types human embryonic kidney cells (HEK), Chinese hamster ovary cells (CHO), and Xenopus laevis melanophores. It can be seen that the different cell types lead to differing amplification factors for the conversion from agonist receptor occupancy to tissue response. 

FIGURE 3.12 Dependence of constitutive receptor activity as ordinates (expressed as a percent of the maximal response to a full agonist for each receptor) versus magnitude of receptor expression (expressed as the amount of human cDNA used for transient transfection, logarithmic scale) in Xenopus laevis melanophores. Data shown for human chemokine CCR5 receptors (open circles), chemokine CXCR receptors (filled triangles), neuropeptide Y type 1 receptors (filled diamonds), neuropeptide Y type 2 receptors (open squares), and neuropeptide Y type 4 receptors (open inverted triangles). Data recalculated and redrawn from [27],... 

FIGURE 5.10 Effects of co-expressed G-protein (G ) on neuropeptide NPY4 receptor responses (NPY-4). (a) Dose-response curves for NPY-4. Ordinates Xenopus laevis melanophore responses (increases light transmission). Ordinates logarithms of molar concentrations of neuropeptide Y peptide agonist PYY. Curves obtained after no co-transfection (labeled 0 jig) and co-transfection with cDNA for Gai6. Numbers next to the curves indicate jig of cDNA of Ga]g used for co-transfection, (b) Maximal response to neuropeptide Y (filled circles) and constitutive activity (open circles) as a function of pg cDNA of co-transfected G g. 

Xenopus laevis melanophores, 82 yeast cells used in, 81-82 Furchgott method, 92, 95, 97-98, 261 Furosemide, 150, 151f... 

Figure 3. Electron micrographs of myelinated axons of Xenopus laevis. Upper figure Cross section of axon showing microtubules in groups in association with membrane-bound organelles. Lower figure Longitudinal section of axon showing neurofilaments and microtubules in close proximity to membrane-bound organelles. (Courtesy of Dr. R. Smith.)...

Lee, J.A., Westerblad, H., Allen, D.G. (1991). Changes in tetanic and resting [Ca ]j during fatigue and recovery of single muscle fibers from Xenopus laevis. J. Physiol. 433, 307-326. 

Machu TK, Harris RA Alcohols and anesthetics enhance the function of 5-hydroxy-tryptaminc3 receptors expressed in Xenopus laevis oocytes. J Pharmacol Exp Ther 271 898-905, 1994... 

Du Preez, L.H., Solomon, K.R., and Carr, J. A. et al. (2005). Population structure of the African Clawed Frog (Xenopus laevis) in maize-growing areas with atrazine application versus non-maize-growing areas in South Africa. African Journal of Herpetology 54, 61-68. 

Gutleb, A.C., Appehnan, J., and Bronkhorst, M. et al. (2000). Effects of oral exposure to polychlorinated biphenyls (PCBs) on the development and metamorphosis of two amphibian species (Xenopus laevis and Rana temporaria). Science of the Total Environment 262, 147-157. 

Hayes, T. (2005). Comment on. Gonadal development of larval male Xenopus laevis exposed to atrazine in outdoor microcosms. Environmental Science and Technology 39, 7757-7758. 

Qin, Z.F., Zhou, J.M., and Cong, L. et al. (2005). Potential ecotoxic effects of polychlorinated biphenyls on Xenopus laevis. Environmental Toxicology and Chemistry 24, 2573-2578. 

Hansen A., Reiss J.O., Gentry C.L. and Burd G. (1998). Ultrastructure of the olfactory organ in the clawed frog, Xenopus laevis during larval development and metamorphosis. J Comp Neurol 398, 273-288. 

Iida A. and Kashiwayanagi M. (1999). Responses of Xenopus laevis water nose to water-soluble and volatile odorants. J Gen Physiol 114, 85-92. 

Iida A. and Kashiwayanagi M. (2000). Responses to putative second messengers and odorants in water nose olfactory neurons of Xenopus laevis. Chem Senses 25, 55-59. 

Mezler M., Konzelmann S., Freitag J., Rossler P. and Breer H. (1999). Expression of olfactory receptors during development in Xenopus laevis. J Exp Biol 202,365-376. 

Oikawa T., Suzuki K., Saito T.R., Tatahashi K.W., et al. (1998). Fine structure of three types of olfactory organs in Xenopus laevis. Anat Rec 252, 301-310. 

Petti M.A., Matheson S.F. and Burd G.D. (1999). Differential antigen expression during metamorphosis in the tripartite olfactory system of the African clawed frog, Xenopus laevis. Cell Tiss Res 297, 383-396. 

Rossler P, Mezler M. and Breer H. (1998). Two olfactory marker proteins in Xenopus laevis. J Comp Neurol 395, 273-280. ... 

Saito S. and Taniguchi K. (2000). Expression patterns of glyco-conjugates in the three distinctive olfactory pathways of the clawed frog, Xenopus laevis. J Vet Med Sci 62, 153-159. 

Gerhart, J., Wu, M., and Kirschner, M. (1984). Cell cycle dynamics of an M-phase-specific cytoplasmic factor in Xenopus laevis oocytes and eggs. J. Cell Biol. 98 1247-1255. 

Mailer, J., Wu, M and Gerhart, J. C. (1977). Changes in protein phosphorylation accompanying maturation of Xenopus laevis oocytes. Dev. Biol. 58 295-312. 

Qian Y-W, Erikson E, Mailer JL 1998a Purification and cloning of a protein kinase that phosphorylates and activates the polo-like kinase Plxl. Science 282 1701-1704 Qian Y-W, Li C, Erikson E, Mailer JL 1998b Activated polo-like kinase Plxl is required at multiple points during mitosis in Xenopus laevis. Mol Cell Biol 18 4262-4271 Richter JD 1999 Cytoplasmic polyadenylation in development and beyond. Microbiol Mol Biol Rev 63 446-456... 

Schwab MS, Kim SH, Terada N et al 1999 The p70(S6K) controls selective mRNA translation during oocyte maturation and early embryogenesis in Xenopus laevis. Mol Cell Biol 19 2485— 2494... 

Tchang F, Gusse M, Soussi T, Mechali M 1993 Stabilization and expression of high levels of p53 during early development in Xenopus laevis. Dev Biol 159 163-172... 

Davis KR, Schultz TW, Dumont JN (1981) Toxic and teratogenic effects of selected aromatic amines on embryos of the amphibian Xenopus laevis. Arch Environ Contamin... 

Lepperdinger, G., el al. (1996). The lipocalin Xlcpll expressed in the neural plate of Xenopus laevis embryos is a secreted retinaldehyde binding protein. Protein Scl 5, 1250-60. 

Zhu, T., et al. Differential recognition of ACE inhibitors in Xenopus laevis oocytes expressing rat PEPT1 and PEPT2. Pharm. Res. 2000, 17, 526-532. 

Yao, S. Y., C. E. Cass, and J. D. Young. Transport of the antiviral nucleoside analogs 3 -azido-3 -deoxy-fhymidine and 2, 3 -dideoxycytidine by a recombinant nucleoside transporter (rCNT) expressed in Xenopus laevis oocytes. Mol. Pharmacol. 1996, 50, 388-393. 

Boumah, C. E., et al. Functional expression of the nitrobenzylthioino-sine-sensitive nucleoside transporter of human choriocarcinoma (BeWo) cells in isolated oocytes of Xenopus laevis. Biochem. J. 1994, 299, 769-773. 

Ngo, L. Y., S. D. Patil, and J. D. Unadkat. Ontogenic and longitudinal activity of Na(+)-nudeoside transporters in the human intestine. Am. J. Physiol. 2001, 280, G475-G481. Chandrasena, G., etal. Functional expression of human intestinal Na+-dependent and Na+-independent nucleoside transporters in Xenopus laevis oocytes. Biochem. Pharmacol. 1997, 53, 1909-1918. 

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