ON THE PHENOL OXIDASE OF EMBRYONIC AND LARVAL STAGES OF THE MEDACA (ORYZIAS LATIPES)1)2)

Tomita, Hideo; Hishida, Tomi‐O

doi:10.1111/j.1440-169x.1961.tb00108.x

Cited by 8 publications

(3 citation statements)

References 4 publications

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“…Zebrafish embryos were treated with 0.2 mM 1‐phenyl‐2‐thiourea (PTU) to inhibit melanin formation. In medaka, inhibition of melanin formation with PTU is not possible without toxic side effects [(Tomita and Hishida, 1961) and own observations). Therefore, we used the Carbio strain for in situ hybridization, which has hypopigmented melanophores due to a particular allele of the slc45a2 ( b ) gene (Fukamachi et al., 2001) and for later stages also the albino i‐3 strain, which has a mutation in the oca2 gene (Fukamachi et al., 2004).…”

Section: Methodsmentioning

confidence: 99%

Pigmentary function and evolution of tyrp1 gene duplicates in fish

Braasch¹,

Liedtke²,

Volff³

et al. 2009

Pigment Cell Melanoma Res

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The function of the tyrosinase-related protein 1 (Tyrp1) has not yet been investigated in vertebrates basal to tetrapods. Teleost fishes have two duplicates of the tyrp1 gene. Here, we show that the teleost tyrp1 duplicates have distributed the ancestral gene expression in the retinal pigment epithelium (RPE) and melanophores in a species-specific manner. In medaka embryos, tyrp1a expression is found in the RPE and in melanophores while tyrp1b is only expressed in melanophores. In zebrafish embryos, expression of tyrp1 paralogs overlaps in the RPE and in melanophores. Knockdown of each zebrafish tyrp1 duplicate alone does not show pigmentary defects, but simultaneous knockdown of both tyrp1 genes results in the formation of brown instead of black eumelanin accompanied by severe melanosome defects. Our study suggests that the brown melanosome color in Tyrp1-deficient vertebrates is an effect of altered eumelanin synthesis. Black eumelanin formation essentially relies on the presence of Tyrp1 and some of its function is most likely conserved from the common ancestor of bony vertebrates.

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Section: Methodsmentioning

confidence: 99%

Pigmentary function and evolution of tyrp1 gene duplicates in fish

Braasch¹,

Liedtke²,

Volff³

et al. 2009

Pigment Cell Melanoma Res

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“…Melanophores are grey or black in colour and contain melanin (Hishida et al., 1961; Ide and Hama, 1969; Nakajima and Obika, 1986; Tomita and Hishida, 1961a,b). Because melanophores obscure developmental events in embryos and adults, the ‘albino’ ( i‐3 / i‐3 ) and/or b / b fish that lack pigmented melanophores are helpful for observing the other three types of chromatophores during development (Figures 2 and 3).…”

Section: Chromatophoresmentioning

confidence: 99%

Pigment pattern formation in the medaka embryo

Lamoreux

Kelsh

Wakamatsu

et al. 2005

Pigment Cell Research

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SummaryFor the study of development of pigmentation, compared with mammalian models, fish offer the advantage of multiple chromatophore types and ready access to the developing embryo for observation and experimental manipulation. Compared with zebrafish embryos, medaka embryos have an additional unique chromatophore-type and superb properties for conditional mutation studies. The rich resources of medaka mutants, combined with data obtainable from other species, potentially offer information not otherwise readily available regarding chromatophore lineage. Here we summarize the embryonic development of normal medaka pigment pattern, based on observations using embryos of a panel of wild type and mutant fish. A more detailed description of development is available in the appendix of the on-line version of this paper (see Supplementary Material). We make some comparisons with zebrafish development to emphasize the increased power of both systems when utilized together. These two models will, in combination, be a powerful system for studies of the embryogenesis and evolution of pigmentation.

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“…IV. DISCUSSION Among the thiocarbamide derivatives thiourea (Tomita & Matsuda,196 l), phenylthiourea (Tomita & Hishida, 1961;Eppig, 1970;Milos & Dingle, 1978) and diethyldithiocarbamide (Abramowitz et al, 1977;Ghate & Mulherkar, 1980) can influence the oxidation of tyrosine to dopa through inhibition of the enzyme tyrosinase (tyrosine hydroxylase) activity, thereby preventing melanogenesis of the melanophores. Members of the thiouracil group have no such effect (Tomita & Matsuda,196 1).…”

Section: Resultsmentioning

confidence: 99%

Melanogenesis in normal and phenylthiourea‐treated eggs and larvae of Sarotherodon aureus

Lanzing

1984

Journal of Fish Biology

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The effects of phenylthiourea on the melanophores of eggs and larvae of Surotherodon nureus were investigated macroscopically and ultrastructurally. Depending on the precise time of application of the drug, partial or total inhibition of melanogenesis of the premelanosomes was obtained, with total inhibition producing artificial albinos. Coincidentally, phenylthiourea also appeared to suppress somatic growth and development of the fry, presumably due to an additional inhibitory effect on the thyroid gland.

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ON THE PHENOL OXIDASE OF EMBRYONIC AND LARVAL STAGES OF THE MEDACA (ORYZIAS LATIPES)¹⁾²⁾

Cited by 8 publications

References 4 publications

Pigmentary function and evolution of tyrp1 gene duplicates in fish

Pigmentary function and evolution of tyrp1 gene duplicates in fish

Pigment pattern formation in the medaka embryo

Melanogenesis in normal and phenylthiourea‐treated eggs and larvae of Sarotherodon aureus

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