[The phenomenon of RNA interference and development of organism].

RNA interference consists in specific mRNA degradation in response to introduction of a double-stranded RNA, homologous in nucleotide sequence. RNA interference was found in eukaryotes and is used in genomics as a powerful method to determine the functions of genes with known nucleotide sequences. RNA interference is considered as a tool of protection against viruses and harmful consequences of mobile elements' transposals.

[Role of double-stranded RNA in eukaryotic gene silencing].

Data on RNA interference, that is, posttranscriptional gene silencing by homologous double-stranded (ds) RNA, are reviewed. Gene silencing caused by exogenous dsRNA in artificial systems and observed in transgenic organisms carrying additional gene copies is considered. Data are summarized on the mechanism that arose during evolution of the Drosophila melanogaster genome to suppress repetitive genes with the use of dsRNA and thereby to prevent male sterility.

[Inhibition of gene expression by administration of homologous double-stranded RNA in Drosophila melanogaster cell culture].

Specific inhibition of gene expression by exogenous homologous double-stranded RNA (dsRNA) in invertebrates and in the early development of vertebrates is termed RNA interference. Cultured cells were cotransfected with reporter plasmids and dsRNA. The inhibitor effect on reporter gene expression depended on the extent of homology between dsRNA and the target gene.

[The tissue localization and secretion of mucin-D in Drosophila melanogaster].

Glycoprotein with biochemical characteristics that allow us to classify it as a glycoprotein of mucin-type was isolated from cultured embryonic cells of Drosophila melanogaster. This is the first finding of mucin-type glycoprotein in insects. Using high-affinity monoclonal antibodies against a carbohydrate epitope, we demonstrated that the accumulation of this glycoprotein in the culture fluid of Drosophila cell line and cultured cells of other insects was inhibited by secretion inhibitors.

[Glycoproteins from Drosophila melanogaster cell culture contains O-bound carbohydrate chains of the Gal(beta1-3)GalNAc type].

The glycoprotein from cultured cells of D. melanogaster, also detected in various insect tissues as a component of the extracellular matrix, was characterized as a mucin-type glycoprotein not yet described in invertebrates. This glycoprotein with an apparent molecular mass of approximately 90 kDa contains about 40% of carbohydrates, largely represented mainly by GalNAc and Gal; its polypeptide moiety is enriched with Thr, Ser, Pro and Gly.

[Chromosomal polymorphism in patients with ovarian hypofunction of central origin].

Comparative data are reported on chromosome polymorphism in adolescent patients with ovarian hypofunction of central origin and healthy women. Chromosome variants with small and very small heterochromatin blocks were found to prevail in the adolescent patients. The incidence of pericentric inversions in chromosomes 1 and 9 was found to be significantly increased in the girls with ovarian hypofunction.

[Activity and appearance of isoenzyme spectrums of some lysosomal hydrolases in biopsy material of human chorion].

Activities and isozyme spectra of alpha-L-fucosidase and beta-D-hexosaminidase were similar both in biopsy material from fetal zone of placenta (chorion) and in chorion tissue obtained after abortion. Evaluation of the isozyme spectrum of these glycosidases in biopsy reeterial of chorion might be carried out for prenatal detection of fucosidosis (deficiency of alpha-L-fucosidase), Tay-Sachs disease (deficiency of hexosaminidase A) and of Sandhoff disease (deficiency of hexosaminidases A and B).

[Partial trisomy 13 for the distal long arm and its prenatal diagnosis].

The results of prenatal diagnosis of fetal karyotype in a woman carrier of reciprocal t(13; 21) (q22; q22) translocation during her second pregnancy are presented. The first pregnancy ended in a term delivery of male twins with multiple malformations typical of the Patau syndrome. No cytogenetic investigation was carried out in this case.

[Glucose-6-phosphate dehydrogenase of Drosophila melanogaster: purification and some properties of normal and mutant enzyme forms].

Two isozymes of glucose-6-phosphate dehydrogenase (EC 1.1.1.

[Prenatal diagnosis of the cri-du-chat syndrome in the case of balanced 5p--; 18p+ translocation in the mother].

The case studied is taken to emphasize the high risk of anomalous progeny being delivered from couples, who are the balanced translocation carriers. The "cri du chat" syndrome was diagnosed in a woman carrier of the balanced reciprocal translocation t(5, 18) (5p13; 18p11) during two successive pregnancies: the diagnosis was postnatal in the first pregnancy, and prenatal in the second. The prenatal diagnosis of the 5p--syndrome was made in amniotic fluid cell culture and verified in fetal skin culture obtained through fetal biopsy.

[Interpretation of the karyotype characteristics of patients with developmental defects of the urogenital system].

35 patients with unclassified urogenital malformations were subjected to clinical and cytogenetic examination. Chromosome aberrations of the mosaicism type were found in 3 women. They were as follows: 45,X/46,XX(2); 45, X/46, XX/47, XXX(1).

[Activity of glycosidases in amniotic fluid cell cultures].

Deficiency of glycosidases is a fundamental feature of the hereditary diseases of glycoconjugate accumulation. The data obtained on activity of glycosidases in cell culture of normal amnionic fluid might be used as standards in prenatal diagnostics of hereditary glycolipidoses and glycoproteinoses. Use of cell culture of amnionic fluid for prenatal diagnosis of Tay-Sachs disease is described.