[Polymorphism of near-centromeric heterochromatin in a population of normal humans]

Polymorphism of constitutive heterochromatin of metaphase chromosomes 1,9 and 16 in 6 normal humans (both men and women) in studied by means of C-staining. Only slight variability in size of C-blocks in one individium (from cell to cell) and a high frequency of C-chromation heteromorphism variants within the population studied is observed. 8 variants of C-heterochromatin (heteromorphic homologues) are found: 4 individuals had 1-2 variants and 1 individual - 3 variants. Quantitative analysis based on measurements of C-blocks confirmed the reliability of the existence of these variants.