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The bacteriophage lambda gt10 DNA containing an insertion of 20 pairs of GC-bases capable of being arranged as Z-form was cloned. Two independent methodological approaches based on the main properties of Z-form were used to study the shape of the insertion: formation of transition bridges composed of unpaired nucleotides between left-rotating Z-forms and right-rotating B-forms of helix (j-domain) and high immunogenic activity of Z-form. O-beta-diethylaminoethylhydroxyamine (OHA), an analogue of hydroxylamine, is capable of reacting specifically with unpaired cytidines. In this work this modification was used to inhibit the process of restriction at BamH1-site adjacent to (gc)10 insertion, that N-Methyl-bis(2-chloethyl) amine (MBCA) is capable of fixing the Z-form of the insertion in situ. Fixed Z-form is conserved even after DNA has been isolated from bacteriophage, thereby providing an opportunity of its identification by anti-Z-antibodies. It was shown that from 4 to 6% of the total number of insertions are in the Z-form. The hypothesis of significant role of Z-form in the process of packing of DNA molecules in capsid is put forward.

According to the analysis of polymorphism of mitochondrial DNA (mtDNA) in eastern Slavs, the frequency of the BamHI-3/AvaII-9/MspI-4 and BamHI-3/AvaII-13/MspI-4 mitotypes are 14% and 3%, respectively. The mitotype BamHI-3/MspI-4 in relation to the (+)AluI/15606 variant was demonstrated to be identical in European populations. It is assumed that the unimodal distribution of the difference values between all pairs of nucleotide sequences of the control mtDNA region that correspond to the BamHI-3/MspI-4 mitogroup indicates an association between the increase of mitotypic diversity in this mitogroup and the exponential growth of European populations in the Neolithic period.