[Liquid crystals and liquid crystal dispersions of DNA-daunomycin complexes]. / Zhidkie kristally i zhidkokristallicheskie dispersii kompleksov DNK-daunomitsin.

The X-ray and optical properties as well as the textures of liquid crystals formed of DNA molecules bound in complex with an anthracycline antibiotic daunomycin were investigated. It was shown that DNA.daunomycin complexes, depending on the extent of alteration of the DNA secondary structure by daunomycin, could yield two types of cholesterics differing in the direction of their spatial twisting as well as nematics. Liquid-crystalline dispersions of DNA.daunomycin complexes have CD spectra with "mirror" bands depending on daunomycin concentration. "Testing" of the orientation of daunomycin molecules on the DNA in liquid-crystalline particles suggested two types of binding.

Cytogenetic investigation of Triticum timopheevii (Zhuk.) Zhuk. and related species using the C-banding technique.

Triticum timopheevii and related species T. militinae (2n=28, A(t)G) and T. zhukovskyi (2n=42, A(m)A(t)G), hybrids T. kiharae, T. miguschovae, the amphidiploid T. timopheevii x T. tauschii (all 2n=42, A(t)GD), T. fungicidum (ABA(t)G) and T. timonovum (2n=56, A(t)A(t)GG) were analyzed using the C-banding technique. Chromosomes of the A(m) and A(t) genomes in the karyotype of T. zhukovskyi differed in their C-banding pattern. Partial substitutions of A(t)-genome chromosomes and a complete substitution of the G-genome chromosomes by homoeologous chromosomes of an unidentified tetraploid wheat species with an AB genome composition were found in the T. timonovum karyotype. A(t)- and G-genome chromosomes in the karyotypes of all studied species had similar C-banding patterns and were characterized by a low level of polymorphism. The comparative stability of the A(t) and G genomes is determined by the origin and specifity of cultivation of studied species.

General features of chromosome substitutions in Triticum aestivum x T. timopheevii hybrids.

Based on a C-banded chromosome analysis of Triticum aestivum x T. timopheevii hybrid lines, we developed a classification of the A(t) and G genome chromosomes that agrees with the standard genetic nomenclature of T. aestivum chromosomes. Transfer of genetic material from T. timopheevii to T. aestivum involved complete chromosomes, chromosome arms, or segments. Frequencies of chromosome substitution were highest for homoeologous group 2 and lowest for group 4. Moreover, B(G) substitutions were frequent compared to A(A(t)). The pattern of chromosome substitutions and rearrangements were unequal and depended on the genotype of the parental T. aestivum cultivar.

[DNA liquid crystals as a possible system of testing the interactions between DNA and biologically active compounds of platinum (II) and various antibiotics]. / Zhidkie kristally DNK--vozmozhnaia sistema testirovaniia vzaimodeistviia s DNK biologicheski aktivnykh soedinenii platiny (II) i nekotorykh antibiotikov.

DNA liquid crystals forming in water-salt solutions containing polyethylene glycol were used as a system for testing consequences of reactions of antitumor compounds belonging to two different groups with molecules of nucleic acids. It was found that with due account of the level of DNA molecule filling with daunorubicin it was possible to form two cholester phases characterized by the textures of "finger prints" and CD spectra with intensive bands of unlike signs, as well as the nematic phase characterized by the texture of the "black twisted fiber" system and the absence of the CD spectrum intensive band. Modification of the DNA molecules resulting from the reaction with cysdichlorodiamine platinum (II) led to formation of a new liquid crystalline phase with properties differing from those of the liquid crystalline phases of the cholester or nematic type.

[Formation of the regular, optical isotropic phase of low molecular weight DNA molecules modified by cis-dichlorodiammineplatinum]. / Obrazovanie uporiadochennoi, opticheski izotropnoi fazy molekul DNK nizkoi molekuliarnoi massy, modifitsirovannykh tsis-dikhlorodiamminplatinoi.

It is shown that condensation of DNA molecules of low molecular mass (less than 1 X 10(6) in NaClO4-containing solution of poly(ethylene glycol) brings about formation of cholesteric liquid crystal phase; pattern of this phase is presented. It has been found by means of X-ray analysis and polarization microscopy that at certain level of modification with cis-dichlorodiammineplatinum (II) the DNA molecules instead of cholesteric structure form an ordered optically isotropic phase. The problem about the causes of the formation of such phase and about the pattern of spatial organisation of adjacent DNA molecules in it remains open.

[2 types of temperature transitions in liquid crystals formed from poly(I).poly(C) molecules]. / Dva tipa temperaturnykh perekhodov zhidkikh kristallov, sformirovannykh iz molekul poli(I).poli(C).

The small-angle X-ray scattering curves, CD spectra and textures of the liquid-crystalline phase formed from poly(I).poly(C) molecules in a water-salt solutions containing poly(ethylene glycol) at different temperatures were obtained. It was found that the heating of poly(1).poly(C) liquid-crystalline phase is accompanied by two types of transitions, the first one--a "cholesteric----"compensated" structure----cholesteric", the second--a "cholesteric----isotropic state" transition. The latter transition takes place at a temperature that corresponds to that of the separation of chains of the double-stranded poly(I).poly(C) molecule.

Chromosomal alterations in the karyotype of triticale in comparison with the parental forms : 2. Heterochromatin of the wheat chromosomes.

Wheat chromosomes of the primary winter hexaploid and octoploid triticales and of the parental durum and common wheat varieties were studied using morphometric analysis. The size of some heterochromatic segments was shown to change in triticale. Telomeric and intercalary C-bands both increased and decreased in size whereas centromeric bands only increased. The size variability of C-bands in triticale B-genome chromosomes decreased in most of the cases and increased only for several specific C-bands. The C-bands of homologous B-genome chromosomes changed in the same direction in both triticale forms. The changes in size of the C-bands found in R-genome chromosomes detected earlier in these triticale forms (Badaeva et al. 1986) were shown to coincide in their pattern with the size changes of C-bands in homeological B-genome chromosomes. Our data are indicative of regular, directed chromosomal changes in the triticale karyotype.

Chromosome alterations in the karyotype of triticale in comparison with the parental forms : 1. Heterochromatic regions of R genome chromosomes.

R genome chromosomes were studied in two forms of primary triticales (hexaploid 'TPG-1/1-78' and octoploid 'AD 825') and in their parent rye forms (Secale cereale L. cv. 'Kharkovskaya 60' and 'VSKhI', respectively) using the methods of C-banding and morphometric analysis. The size of some heterochromatic segments was shown to alter in the karyotype of triticale. An increase in size was detected approximately in half of all telomeric C-bands; the size of the other C-bands either decreased or did not change. The frequencies of these alterations were 1∶1. The variability in the size of telomeric C-bands in rye chromosomes diminished in both triticales studied. The two triticale forms inherited variants of R genome chromosome polymorphism predominantly with the medium size range of telomeric C-bands. The centromeric C-bands in both triticale forms either enlarged or did not alter. Possible mechanisms responsible for the observed pattern of alterations are discussed.

Cytogenetic analysis of forms produced by crossing hexaploid triticale with common wheat.

Hexaploid triticales were crossed with common wheats, and the resultant froms were selected for either triticale (AD 213/5-80) or common wheat (lines 381/80, 391/80, 393/80). The cytogenetic analysis showed that all forms differ in their chromosome composition. Triticale AD 213/5-80 and wheat line 381/80 were stable forms with 2n = 6x = 42. Lines 391/80 and 393/80 were cytologically unstable. In triticale AD 213/5-80, a 2R (2D) chromosome substitution was found. Each of the three wheat lines had a chromosome formed by the translocation of the short arm of IR into the long arm of the IB chromosome. In line 381/80, this chromosome seems to be inherited from the 'Kavkaz' wheat variety. In lines 391/80 and 393/80, this chromosome apparently formed de novo since the parent forms did not have it. The karyotype of line 381/80 was found to contain rye chromosomes 4R/7R, 5R and 7R/4R. About 15% of the cells in line 391/80 contained an isochromosome for the 5R short arm and also a chromosome which arose from the translocation of the long arms of the 5D and 5R chromosomes. About one-third of the cells in the common wheat line 393/80 contained the 5R chromosome. This chromosome was normal or rearranged. Practical applications of the C-banding technique in the breeding of triticale is discussed.

[Effect of polyethyelene glycol on proliferation of cultured Chinese hamster cells]. / Vliianie poliétilenglikolia na proliferatsiiu kul'tiviruemykh kletok kitaiskogo khomiachka.

Chinese hamster cells in suspension were treated with PEG 4000 for 20 min. It was found that cell size began to diminish already when a 5% PEG solution was used, and reached the minimal value in a 20% PEG solution. A pronounced cell death was observed when PEG concentration exceeded 20%, but cells that survived retained their proliferation potential. It is concluded that the cell death results from hypoosmotic shock when cell suspension in PEG solution is diluted.

Linear differentiation of cereal chromosomes : I. Common wheat and its supposed ancestors.

Using the Giemsa technique of differential staining (the BSG test), we have studies the karyotypes and constructed the idiograms of T. aestivum L. var. 'Diamant' and 'Chinese Spring', T. Monococcum L. v. 'hornemannii' ssp. roles occidentali georgicum Dek., Aegilops squarrosa L. v. 'Meeyeri', T. aestivum. The karyotypes of 'Chinese Spring' and 'Diamant' differ drastically both in total structural heterochromatin content and its localization on the nine morphologically homeologous chromosomes. The rest of the twelve pairs of chromosomes showed no morphological similarity. This indicates considerable differences in the phylogeny of the varieties, and also an absence of unique karyotype in T. aestivum.Three chromosomes of Ae. Squarrosa are similar to those of 'Chinese Spring', yet, on the whole, the chromosomal structural specificity of the diploids studied is so high that we fail to understand the nature of the homology between common wheat and its supposed diploid ancestors.The role of introgression in the evolution of the genomes of Triticum and Aegilops, and also the meaning of the conjugation and BSG tests in resolving the phylogeny, is discussed.

Linear differentiation of cereal chromosomes : II. Polyploid wheats.

The BSG test was used in a comparative study of the linear chromosome differentiation and the idiograms of T. Macha ssp. tubalicum v. 'letschchumicum ' Dek. et Men., T. georgicum Dek., T. timopheevi. Zhuk., T. carthlicum Nevski, T. dicoccum Schrank, v. 'rufum', T. durum Desf. v. 'Arnautka' were compiled.The karyotype of each polyploid wheat species consists of two groups of chromosomes. The first is formed by ten pairs of "constant" chromosomes occurring almost in all species and the second by all the rest of the "variable" chromosomes that are either fully specific for the species in question or occur only in a few species. T. timopheevi largely differs from other species of polyploid wheats in the high level and specific localization of structural heterochromatin on chromosomes. The rols of introgression in wheat evolution and the necessity of establishing a General Cytological Nomenclature of Cereal Chromosomes are discussed.

Linear differentation of cereal chromosomes : III. Rye, triticale and 'Aurora' variety.

The BSG test was used in an investigation of the linear differentiation in rye variety 'Zhitkinskaya', common wheat variety 'Aurora' and two secondary Triticale namely AD-196 and F-1239.Chromosomes of 'Aurora' variety and wheat chromosomes within Triticale may be easily divided into "constant" and 'variable' chromosomes as described previously (lordansky et al. 1977; Zurabishvili et al 1977).It is necessary to emphasize that the diversity of "variable" chromosomes underlies karyotypical polymorphism within wheat and Triticale species. The polymorphism observed exists in parallel with strict homomorphism of homologous chromosomes.In IB chromosomes of 'Aurora' variety, the short arm is substituted by the rye chromosome arm. The karyotype of Triticale AD-196 consists of six pairs of rye chromosomes and fifteen pairs of wheat chromosomes.

[Spiralization dynamics of the eu- and heterochromatin of heteromorphic homologs of the 1st pair of human chromosomes]. / Analiz dinamiki spirilizatsii éu- i geterokhromatina geteromorfnykh gomologov 1-i pary khromosom cheloveka.

Peculiarities of mitotic spiralization of eu- and heterochromatic parts of heteromorphic homologous chromosomes No 1 are investigated. The homologues differ in size of their centromeric heterochromatin segments. In the spiralization range studied (the total lengths of chromosome pair equal to 8.2+25.6 mcm) the lengths of any euchromatic and heterochromatic part change approximately by 3 and 2 times, resp. It is shown that if the chromosome contraction level is not taken into consideration, neither absolute nor relative length of heterochromatic segment can be used for measuring the ratio of heterochromatin. Recommendations for quantitative determination of heterochromatin in chromosome No 1 are given.