scholarly journals A wide variety of Mitf transcript variants are expressed in the Xenopus laevis periodic albino mutant

2018 ◽  
Vol 23 (8) ◽  
pp. 638-648 ◽  
Author(s):  
Toshihiko Fukuzawa
Keyword(s):  
Xenopus Laevis ◽  
Transcript Variants ◽  
Albino Mutant ◽  
Periodic Albino

Further studies on the melanophores of periodic albino mutant of Xenopus laevis

Development ◽  
1986 ◽  
Vol 91 (1) ◽  
pp. 65-78
Author(s):  
T. Fukuzawa ◽  
H. Ide
Keyword(s):  
Xenopus Laevis ◽  
Microscopic Level ◽  
Wild Type ◽  
Light Microscopic Level ◽  
In Vitro Proliferation ◽  
Albino Mutant ◽  
Site Of Action ◽  
Periodic Albino

It is still unknown why dermal melanophores disappear during larval development, and why no or very few epidermal melanophores appear during and after metamorphosis, in Xenopus laevis showing periodic albinism (ap). To elucidate these points, we investigated (1) the occurrence of depigmentation in mutant (ap/ap) melanophores during in vitro proliferation and (2) the incidence of melanophore differentiation from mutant melanoblasts in the skin in vitro. During in vitro proliferation of mutant melanophores, ap-type melanosomes decreased in number gradually and instead the number of premelanosomes increased in the cells, which caused depigmentation at the light microscopic level in the culture. Depigmentation was observed only in mutant melanophores, and not in wild-type (+/+) melanophores. These results suggest that autonomous depigmentation of mutant dermal melanophores is the cause of the disappearance of these cells in vivo. Dopa-positive melanoblasts were demonstrated in both wild-type and mutant skins. However, the melanoblasts of metamorphosed mutant froglets did not differentiate in vitro, while those of wild-type froglets did. These results suggest that mutant melanoblasts in the skin of froglets lose the potency to differentiate into melanophores, and that this causes the lack of mutant melanophores in the froglets. The site of action of the ap gene is also discussed.

A Decreased Number of Primordial Germ Cells and the Small Numbers and Reduced Sizes of Germinal Granules in the Periodic Albino Mutant of Xenopus laevis

1993 ◽  
Vol 160 (1) ◽  
pp. 289-291 ◽  
Author(s):  
Minoru Kotani ◽  
Kohji Ikenishi ◽  
Etsuko Torii ◽  
Etsuko Amemiya ◽  
Masami Kadowaki
Keyword(s):  
Xenopus Laevis ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Germinal Granules ◽  
Albino Mutant ◽  
Periodic Albino

A comparative ultrastructural and physiological study on melanophores of wild-type and periodic albino mutants of Xenopus laevis

1982 ◽  
Vol 222 (1) ◽  
pp. 1-9 ◽  
Author(s):  
R. Seldenrijk ◽  
K. G. H. Huijsman ◽  
A. M. A. Heussen ◽  
F. C. G. van de Veerdonk
Keyword(s):  
Xenopus Laevis ◽  
Physiological Study ◽  
Wild Type ◽  
Periodic Albino

High tyrosinase activity in albino Xenopus laevis oocytes

Development ◽  
1976 ◽  
Vol 36 (3) ◽  
pp. 555-559
Author(s):  
A. H. Wyllie ◽  
E. M. De Robertis
Keyword(s):  
Molecular Weight ◽  
Xenopus Laevis ◽  
Specific Activity ◽  
High Specific Activity ◽  
Low Molecular Weight ◽  
Xenopus Laevis Oocytes ◽  
Melanin Synthesis ◽  
Wild Type ◽  
Albino Mutant

Tyrosinase was measured in oocytes of the recently described albino mutant (avav) of Xenopus laevis. Although these oocytes show no pigmentation and the eggs are known to contain no melanosomes, tyrosinase — which is probably the only enzyme necessary for melanin synthesis from tyrosine — was increased more than twofold relative to the wild type. Tyrosinase recovered from albino and wild type oocytes showed the same KM with respect to tyrosine, and this was not altered by previous gonadotrophin stimulation in vivo. The tyrosi-nase assay, based on [14]tyrosine incorporation into acid-insoluble products, was of greater sensitivity than previously described methods of the same type, through removal of low molecular weight material from the oocyte homogenate prior to incubation, and the use of tyrosine of high specific activity.

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