In Antarctic summer 1983/1984 samples of planktonie and attached diatoms were collected in the Admiralty Bay (King George Island, South Shetland Islands) as well as samples of planktonie diatoms in the region of South Orkneys, Drake Passage and Bransfield Strait (BIOMASS-SIBEX Project). Using gas chromatography residues of chloroorganic pesticides, namely the compounds of the DDT group and HCH isomers were determined. It was found that the highest values of the content of these compounds occurred in attached diatoms coming from areas continuously washed with water from the melting glacier, in planktonie diatoms from the samples of the Admiralty Bay and from strongly glaciated regions. A hypothesis was put forward that along with the direct atmospheric transport the release of the deposits of these compounds from ice and glaciers during their melting is an additional source of input of chloroorganic biocides into Antarctic waters. Diatoms are good indicators of this process.
5.8S ribosomal RNA plays an important role in protein synthesis and eukaryotic ribosome translocation. Contact DNA insecticides based on antisense fragments of 5.8S ribosomal RNA gene of gypsy moth Lymantria dispar L. showed prospective insecticidal activity on its larvae. The most pronounced insecticidal effect was found for antisense fragments 10 and 11 nucleotides long (oligoRIBO-10 and oligoRIBO-11), whereas 12 nucleotides long fragment (oligoRIBO-12) caused the lowest level of insect mortality. This data corresponds to results obtained earlier using rabbit reticulocyte and wheat germ extracts, where maximum inhibition of protein synthesis was observed when a relevant oligomer 10-11 nucleotides long was used, whilst longer chain lengths resulted in reduced inhibition. Using oligoRIBO-11 fragment we have shown penetration of antisense oligonucleotides to insect cells through insects’ exoskeletons. MALDI technique registered the penetration of the oligoRIBO-11 fragment into insect cells after 30 min and a significant response of insect cells to the applied oligonucleotide after 60 min, which indicates not only that the oligonucleotide enters the insect cells, but also the synthesis of new substances in response to the applied DNA fragment. Contact DNA insecticides developed from the L. dispar 5.8S ribosomal RNA gene provide a novel biotechnology for plant protection using unmodified antisense oligonucleotides.