[Correlation of polymorphism of heterochromatin segments with hybridization on chromosome preparations of various cloned repeated human DNA sequences].

Comparison between results of measurements of heterochromatic regions detected by differential C and DA/DAP1 staining and the hybridization data of two cloned repeated human DNA sequences one alphoid (pH S05) and the other the satellite DNA III (pPD18) on chromosome preparations was made. A positive correlation of heterochromatic region sizes on several chromosomes and the amount of label over them detected after hybridization with both alphoid and satellite sequences was shown, the correlation with the latter being more pronounced.

[Quantitative analysis of chromosomal localization of two human cloned satellite DNA III sequences by in situ hybridization].

Chromosomal location of two cloned human satellite DNA III sequences pPD9 and pPD18 has been studied in 30 individuals by in situ hybridization. Pericentromeric localization of the DNA subsets studied was found in practically all chromosomes of the set. The majority of label was observed over the pericentromeric region of chromosome 9 (38.

[Use of a cloned alphoid repetitive sequence of human DNA in studying the polymorphism of heterochromatin regions of chromosomes].

Chromosomal location of the cloned fragment pHS05 of alphoid DNA from the collection of human PstI restricts has been studied in 38 individuals by in situ hybridization. Pericentromeric localization of the DNA fraction studied was found in practically all chromosomes of the set. Significant interchromosomal and poorly expressed interindividual differences were detected in a number of the copies of the sequence class investigated.

[A method of analyzing the chromosome localization of repetitive nucleotide sequences by using hybridization in situ].

To increase precision in the quantitative analysis of chromosomal distribution of repeated DNA sequences detected by in situ hybridization, a number of factors important in studies of the molecular basis of chromosome polymorphism should be considered. While analysing results of hybridization, one should only use the number of grains over the sites of their regular localization, instead of those over the whole chromosome. It is also evident that to decrease variability conditioned by differences in the labelling degree of separate cells, the relative numbers of labelled grains over chromosomes should be used in the analysis and not the absolute ones.

[Quantitative analysis of C-segments of chromosomes 1, 9, 16 and Y in couples with reproductive disorders].

A comparative analysis of structural variability of C-bands on chromosomes 1, 9, 16 and Y was conducted in 50 phenotypically normal adults and 25 couples with repeated spontaneous abortions. Reduction of both the total amount of heterochromatin in the cell and the lengths of these regions on chromosomes 1, 9, and 16 is revealed in the group of pathology. No differences were found in the lengths of C-bands on Y chromosome.

[Q-band chromosome polymorphism in couples with reproductive disorders].

A comparative analysis of Q-band polymorphisms was conducted in phenotypically normal individuals and couples with repeated spontaneous abortions. In the group of pathology reduction of the following phenomena was found: frequencies of brilliant fluorescence in bands 4p11q11, 14p11, 14p13, 15p11, 21p13; the mean numbers of the brilliant fluorescent segments per cell per individual; frequencies of extremely large ("marker") Q-bands. All these findings coincided with our earlier published data on reduction of the C-heterochromatin amount in the same group of pathology.