Circular mitochondrial DNA from Xenopus laevis and Rana pipiens

Chromosoma ◽  
1967 ◽  
Vol 20 (4) ◽  
pp. 445-449 ◽  
Author(s):  
David R. Wolstenholme ◽  
Igor B. Dawid
Keyword(s):  
Mitochondrial Dna ◽  
Xenopus Laevis ◽  
Rana Pipiens

An Experimental Analysis of the Development of the Haploid Syndrome in Embryos of Xenopus laevis

Development ◽  
1963 ◽  
Vol 11 (1) ◽  
pp. 267-278
Author(s):  
Louie Hamilton
Keyword(s):  
Xenopus Laevis ◽  
Experimental Analysis ◽  
Rana Pipiens ◽  
Animal Pole ◽  
Pole Cells

Haploid vertebrates may occur spontaneously but are very rare (Fankhauser, 1941; Humphrey & Fankhauser, 1957); however, haploids may be experimentally produced in fish (Swarup, 1959) and in mammals (Beatty, 1953), while amphibian eggs may be so treated that all developing embryos are haploid (Porter, 1939; Gurdon, 1960). The full descriptions of the development of haploid Rana pipiens (Porter, 1939) and R. nigromaculata (Miyada, 1960) apply so well to Xenopus laevis that only the most important points will be touched on here. Haploid amphibians may be identified at the beginning of gastrulation since their animal pole cells are smaller at a given stage than are those of diploids. In all haploid Anura the onset of gastrulation is delayed, and thereafter haploids become progressively more retarded in their development. Their neural plates are shorter, and when the neural folds have closed it can be seen that the embryos are microcephalic and suffer from lordosis and a bulging abdomen.

Synthesis of mitochondrial RNA by full-grown and maturing oocytes of Rana pipiens and Xenopus laevis

1975 ◽  
Vol 45 (1) ◽  
pp. 44-55 ◽  
Author(s):  
Andrew C. Webb ◽  
Michael J. LaMarca ◽  
L.Dennis Smith
Keyword(s):  
Xenopus Laevis ◽  
Rana Pipiens ◽  
Mitochondrial Rna

Ontogeny and localization of the lens crystallins in Xenopus laevis lens regeneration

Development ◽  
1974 ◽  
Vol 32 (3) ◽  
pp. 783-794
Author(s):  
Samir K. Brahma ◽  
David S. McDevitt
Keyword(s):  
Xenopus Laevis ◽  
Rana Pipiens ◽  
Staining Method ◽  
Early Stage ◽  
Lens Protein ◽  
Lens Crystallins ◽  
Lens Regeneration ◽  
Stage 4 ◽  
Indirect Immunofluorescence Staining ◽  
Normal Lens

Ontogeny and localization of the lens crystallins, especially the γ-crystallins were investigated in Xenopus laevis lens regenerating system by the ‘indirect’ immunofluorescence staining method. Antibodies directed against Rana pipiens γ-crystallin antigen were used for the detection of this crystallin; the validity of such an experiment has been shown in a previous report. To detect total lens proteins we used X. laevis anti-total lens protein antibody. The regenerates were staged according to Freeman (1963) and the first positive reaction with both the two antisera was observed in an early stage-4 regenerate . The site of theimmunofluorescence reaction was nearly identical in both, suggesting that γ-crystallinsare one of the first, if not the first of the lens crystallins to appear during lens regeneration. The secondary fibres, when developed, showed less immunofluorescence than the primary fibres with R. pipiens anti-γ crystallin antibody, though the reaction was intense in the secondary fibres with X. laevis anti-total lens protein antibody. The intensity and distribution of immunofluorescence increased with the growth of the lens. With the R. pipiens anti-γ crystallin antibody, the lens epithelium did not show any immunofluorescence reaction at any stage of lens regeneration. With X. laevis anti-total lens protein antibody, the epithelium showed an immunofluorescence reaction earlier than in the normal lens development. With the two antisera we used, we did not observe any immunofluorescence outside the lens tissue.

Patterns of Particle Movement in Nerve Fibres In Vitro- an Analysis by Photokymography and Microscopy

1972 ◽  
Vol 11 (3) ◽  
pp. 875-886
Author(s):  
M. BERLINROOD ◽  
S. M. McGEE-RUSSELL ◽  
R. D. ALLEN
Keyword(s):  
Electron Microscopy ◽  
Xenopus Laevis ◽  
Particle Velocity ◽  
Rana Pipiens ◽  
Ambystoma Tigrinum ◽  
Particle Movement ◽  
Nerve Fibres ◽  
Amphibian Embryos ◽  
Particle Velocities

Tissue-cultured nerve fibres derived from 3 species of amphibian embryos were composed of bundles of neurites, when viewed by electron microscopy, and contained particles moving in both directions by saltations. Photokymographic analysis of ciné microscopy records taken with Zeiss differential interference optics demonstrated instantaneous particle velocities ranging from 0.15 to 1.8 µm 8-1 (13-155 mm/day) in Rana pipiens cultures; 0.16-0.8 µm s-1 (14-74 mm/day) in Ambystoma tigrinum cultures and 0.6-2.25 µm s-1 (45-194 mm/day) in Xenopus laevis cultures. Measured pathlengths for particles saltations ranged from 4 to 63 µm. No correlations between particle velocity and pathlength were found.

Mitochondrial DNA synthesis in oocytes of Xenopus laevis

1979 ◽  
Vol 119 (2) ◽  
pp. 414-418 ◽  
Author(s):  
Andrew C. Webb ◽  
Catherine J. Camp
Keyword(s):  
Mitochondrial Dna ◽  
Xenopus Laevis ◽  
Dna Synthesis ◽  
Mitochondrial Dna Synthesis

Effects of agricultural pesticides on the immune system of Xenopus laevis and Rana pipiens

2004 ◽  
Vol 67 (1) ◽  
pp. 33-43 ◽  
Author(s):  
M.S. Christin ◽  
L. Ménard ◽  
A.D. Gendron ◽  
S. Ruby ◽  
D. Cyr ◽  
...  
Keyword(s):  
Immune System ◽  
Xenopus Laevis ◽  
Rana Pipiens ◽  
Agricultural Pesticides

Spectral and polarization sensitivity of photocurrents of amphibian rods in the visible and ultraviolet

1998 ◽  
Vol 15 (2) ◽  
pp. 319-331 ◽  
Author(s):  
ADRIAN G. PALACIOS ◽  
RANJANA SRIVASTAVA ◽  
TIMOTHY H. GOLDSMITH
Keyword(s):  
Xenopus Laevis ◽  
Rana Pipiens ◽  
The Other ◽  
Ambystoma Tigrinum ◽  
Maximal Response ◽  
Polarization Sensitivity ◽  
Spectral Position ◽  
Long Wavelength ◽  
The Mean ◽  
Α Band

Photocurrents from isolated rods of adults and sub-adults of three species of amphibians, Rana pipiens, Ambystoma tigrinum, and Xenopus laevis, were measured with suction pipette electrodes. The intensity for a half-maximal response was 0.91 ± 0.48 photons μm−2 flash−1 (mean ± s.d., 10-ms flashes) for Rana, 0.92 ± 0.44 for Ambystoma, and 6.14 ± 1.33 for Xenopus. The mean number of photoisomerizations at half-saturation was 22 ± 12 for Rana, 50 ± 24 for Ambystoma, and 221 ± 48 for Xenopus. The photocurrent per photoisomerization is several times smaller in Xenopus rods than in the other two species. Spectral sensitivity was measured from 277–737 nm with light polarized both parallel and perpendicular to the planes of the membrane disks. Dichroism fell in the near UV and was absent in the region of absorption by tryptophan and tyrosine. Maximum sensitivity of Rana was at 503.9 ± 2.6 nm (n = 86), and of Ambystoma, 505.8 ± 1.8 nm (n = 24). Animals from these same batches that were sampled by HPLC had no 3-dehydroretinal (retinal2). Xenopus containing about 94% retinal2 and 6% retinal1 had λmax at 519.3 ± 2.7 nm (n = 11). Spectral position of the β-band, estimated by the method of Stavenga et al. (1993), appears to be at longer wavelengths in amphibian photoreceptors than in other vertebrates. Fits of log sensitivity to a normalized-frequency template that tracks the long-wavelength tail of the α-band (Lamb, 1995) show that the rod pigments of Rana and Ambystoma are slightly narrower than those found in the photoreceptors of fish and mammals.

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