[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.