Localisation et signification des zones Q observées sur les chromosomes mitotiques de l'amphibien Pleurodeles waltlii Michah. après coloration par la moutarde de quinacrine

Abstract

Metaphase plates from tailbuds of Pleurodeles waltlii embryos (stage 34) with or without preceding cold treatment were obtained by squashing followed by quinacrine mustard staining. In both cases, caryograms were established and sites of Q bands located. — Most of the secondary constrictions exhibit very high fluorescence. In general, it is the same for the centromeric parts, but their fluorescence is quenched very strongly by cold treatment. — The proximal part of the long arm of chromosome VII and satellites of chromosomes III and XI exhibit dull fluorescence. All these sites are compared with heterochromatin localization. The relation between banding and base composition or non-histone proteins interactions is discussed.