Generation of three Duchenne muscular dystrophy patient-derived induced pluripotent stem cell (iPSC) lines ICGi002-A, ICGi002-B and ICGi002-C.

Duchenne muscular dystrophy (DMD) is a severe and rapidly progressive hereditary muscular disease with X-linked recessive inheritance, occurring mainly in males. A complete loss of dystrophin resulted from out-of-frame deletion mutations in the DMD gene leads to Duchenne muscular dystrophy. DMD induced pluripotent stem cells (iPSCs) are a suitable cell model to study muscle development and disease mechanisms underlying muscular dystrophy and to screen novel compounds with potential therapeutic effects. We generated iPSCs from a DMD patient using non-integrating episomal plasmid vectors. The obtained iPSC lines showed ESC-like morphology, expression pluripotency markers, displayed a normal karyotype and possessed trilineage differentiation potential.

[Patterns of transposable elements distribution on the Drosophila melanogaster polytene chromosomes before and after selection for a quantitative trait].

The effect of selection for radius vein length on the distribution of hybridization sites of the P and hobo transposons and the mdgl and mdg2 retrotransposons on polytene chromosomes of Drosophila melanogaster salivary glands was studied. The patterns of these transposable elements (TEs) distribution were polymorphic in both the parental strain and selected strains. The similarity in mdg1 and mdg2 patterns between strains selected in one direction was closer than between strains selected in opposite directions, but the selected strains were closer to each other than to the parental strain regardless of selection direction. No mdg2 hybridization sites that would be absent in the control were found in the selected strains. There were more mdg2 and hobo hybridization sites in the strains selected in the (+) direction than in the (-) direction. The mobility of hobo copies in the strains studied correlated with the presence of its full-sized copy in the genome. The polymorphism of all TEs studied except for mdgl was greater for strains selected in the (+) direction that in the (-) direction. These facts suggest that some TEs migrate over the genome independently of selection, and others are markers of evolutionary events rather than their causes.

[Change in the distribution of transposable elements in isogenic strain--cause or consequence in Drosophila melanogaster selection for quantitative traits?].

The distribution patterns pf hobo transposon and Dm412 retrotransposon hybridization sites on the salivary gland polytene chromosomes from the larvae of Drosophila melanogaster isogenic strain 51, used for analyzing the effect of transposable element (TE) transposition on the selection for quantitative traits, were studied, It was demonstrated that at least half Dm412 hybridization sites were retained 15 years after isogenization; the frequency of Dm412 transposition varied from 2.0 x 10(-4) to 8.8 x 10(-5) depending on whether the appearance of the same hybridization sites in some individuals were regarded as independent events or as a manifestation of the sample heterogeneity. The distribution patterns of hobo hybridization sites in two isofemale strains derived from isogenic strain 51 differed more noticeably: the number of hobo sites in one of the derivative strains was threefold smaller than in another and only a fraction of the sites was common. Within each derivative strain, the TE distribution was uniform, suggesting that inbreeding had no effect on the Dm412 activity in this strain. The rates of change in the distribution patterns of various TEs in strain 51 corresponded to their spontaneous transposition rates. As isogenic strain accumulates the polymorphism in TE distribution without selection, the TEs are more likely to be the markers of selection events than their inducers. Thus, when studying the effects of various environmental factors on TE transposition even in isogenic strains, it is necessary to perform rounds of close inbreeding to reduce the potential polymorphism.

[Polymorphism of yellow locus in Drosophila melanogaster from natural populations].

We studied molecular characteristics of yellow (y; 1-0.0) locus, which determines the body coloration of phenotypically wild-type and mutant alleles isolated from geographically distant populations of Drosophila melanogaster in different years. According to Southern data, restrictions map of yellow locus of all studied strains differ from each other as well as from that of Oregon stock. FISH analysis shows that in the neighborhood of yellow locus in X chromosome neither P nor hobo elements are found in y1-775 stock, while only hobo is found there in y1-859 and y1-866 stocks, only P element in y+sn849 stock, and both elements in y1-719 stock. Thus, all studied mutant variants of yellow are of independent origin. Yellow locus residing at the very end of X chromosome (region 1A5-8 of cytologic map) carries significantly more transposon than retrotransposon-induced mutations, as compared to white locus (regions 3C2). It is possible that transposons are more active than retrotransposons at the chromosomal ends of D. melanogaster.

[Three-dimensional organization of telomeres in the Drosophila melanogaster salivary glands nuclei].

The 3D-FISH was employed to investigate the telomere topology in polytene nuclei of salivary glands of Drosophila melanogaster. The majorities of telomeres in polytene nuclei of salivary glands in Drosophila strain y(2-717) are localized in the nuclear central area and have no contacts with nuclear membrane. In females of this strain, ectopic contacts between telomeres occur at 25 % higher frequency than in males. HeT-A DNA in y(2-717alk3-2) strain, which is a derivative of y(2-717) carrying an inversion between 1D and 13C bands, is found in region 13 of X chromosome. The frequency of ectopic contacts of telomeres in y(2-717alk3-2) males is 10 % higher than that in y(2-717) strain. The number of ectopic contacts can be significantly different in independent experiments, possibly indicating the role of random factors in the contact formation.

[The effect of gamma-radiation on induction of the hobo element transposition in Drosophila melanogaster].

The transposition frequency of the hobo mobile element in four successive generations of Drosophila melanogaster strain y2-717 after an acute gamma-irradiation with a dose of 30 Gr amounted to 7.5 x 10(-4) per site per genome per generation. Under the same conditions, PCR analysis of the genomic DNA of y2-717 flies detected new variants of defective hobo sequence. No changes in the hobo localization and PCR products compared with the control were detected in the case of single irradiation with doses of 3 and 30 Gr. The localizations of hobo element on polytene chromosomes of y2-717 strain did not change during 11 generations after five exposures of flies to 30 Gr. Irradiation of a highly unstable D. melanogaster strain y+743 did not increase the number of families with mutant progeny, yet increased the total number of mutant descendants almost twofold, from 5 to 9%.