Pterin Synthesis in the Amphibian Neural Crest Cell

Abstract

A LARGE amount of fluorescent substances of pterin type has been known to exist in the coloured skin of amphibians and they were shown to accumulate in chromatophores such as melanophores and xanthophores (allophores), as in the bull-frog¹. During the development, pterins appear simultaneously with the pigmentation in chromatophores². Moreover, certain substances of pterin type have been reported to accelerate the in vitro formation of Dopa-melanin^3,4. These facts suggest an intimate relation between the pterins and pigment formation in chromatophores. To analyse such a relation, it is desirable to know where pterins are synthesized in the course of embryonic development. The present experiment was carried out to ascertain the capacity of pterin synthesis in the pro-pigment cells of urodelan embryos. Pterins were extracted with 70 per cent ethanol and chromatographed on paper using the following solvents: n-propanol/1 per cent ammonia (2 : 1), n-butanol/acetic acid/water (4 : 1 : 1) and 5 per cent acetic acid.