CYTOLOGICAL ANALYSES OF A 14P+ VARIANT BY MEANS OF N-BANDING AND COMBINATIONS OF SILVER STAINING AND CHROMOSOME BANDINGS

An inherited human karyological variant (14p+) has been studied with a number of cytochemical techniques. The short arm of this variant chromosome 14 is nearly as long as the long arm, giving the chromosome a submetacentric to metacentric appearance. In conventionally Giemsa-stained preparations, a maximum of three secondary constrictions can be observed in the marker arm. The secondary constrictions are silver-positive in Ag-NOR preparations. However, the entire arm stains deeply in N-banded preparations. The 14p+ arm also Q-negative, C-negative, G-negative, and R-positive with an almost homogeneous texture. The difference between N-banding and silver staining is interpreted as the result of gene activities of the ribosomal cistrons. © 1979 Springer-Verlag.