[Nucleotide composition of constitutive heterochromatin of Pleurodeles waltlii].

Complementary to previous works implying other staining or labeling techniques, this study used chromomycin A3, a specific fluorochrome for G and C bases, to show that in Pleurodeles waltlii Michah. (Amphibian, Urodele) the mitotic chromosome specific heterochromatin consisted of a DNA particularly rich in either of the two types of bases and the near constant presence of argyrophilic proteins. The more the DNA was rich in A and T bases, the more the argyrophilic proteins were abundant.