[Species specific variant of human centromeric DNA repeats: localization on chromosome 18 and recent amplification in human ancestral line].

Plasmid library of rapidly renaturating fraction of human DNA was constructed. The library was used for isolation of primate-specific DNA repeats. A clone (1hsp-4) which was intensively hybridizable with human DNA exclusively and produced no signals when hybridized with animal DNAs including the ones from orangoutan and chimpanzee was isolated.

[Ribosomal genes of animals from the radiobiology aspect].

The content of ribosomal genes was determined in DNA of guinea pig, man, rat and rabbit, i. e. of mammals differing in radiosensitivity.

[Changes in the pyrimidine blocks of thymic DNA immediately after gamma irradiation of the animal in a sublethal dosage].

Pyrimidine clusters of thymus DNA were determined in normal conditions and 5-10 min after gamma-irradiation of rabbits with a dose of 2 Gy. It was shown that a relative content of isopliths I and II significantly increased and that of isopliths V and VIII decreased in the exposed DNA as compared to normal. When isopliths were divided into the components a relative content of C2T2 fragments significantly increased in the exposed DNA while that of CT3 and T5 decreased.