Cloning of Alu-containing cDNAs from human fibroblasts and identification of small Alu+ poly(A)+ RNAs in a variety of human normal and tumor cells.

Two clones have been selected from a human fibroblast cDNA bank. By DNA sequencing the clones were shown to contain Alu elements located near the ends of the cDNA inserts. DNA of the clones was used for Northern blot hybridization analysis of a number of poly(A)-containing RNAs from normal human tissues (brain, stomach, uterus, spleen, fibroblasts) and tumors (neurinoma, glioma, neuroblastoma, liposarcoma, adrenal cortex adenocarcinoma). All RNA samples reveal a heterodisperse distribution of Alu transcripts with discrete bands in the region of 7-12 S RNA. The majority of these small poly(A)+ Alu+ RNAs contain Alu sequences only in one (canonical) orientation with functional signals including the split promoter for RNA polymerase III.

[Sequences containing the Alu elements from a human fibroblast cDNA clone library: nucleotide sequence and expression in various tissues]. / Posledovatel'nosti, soderzhashchie élementy Alu, iz banka klonov kDNK fibroblastov cheloveka: opredelenie nukleotidnoi posledovatel'nosti i ékspressiia v raznykh tkaniakh.

Alu containing cDNA clones were isolated from a human fibroblast cDNA library. The nucleotide sequences of two clones were determined. In both cases Alu repeats appeared to be situated in the regions presumably corresponding to the 3'-end of mRNA. The comparison of the unique sequences of those clones did not show any homology between them. Both cDNA clones contained large open reading frames, extending into the Alu regions. DNA of one clone was used as a probe for Northern blot-hybridization analysis of poly(A)+ cytoplasmic RNA from some normal and tumor human tissues. All RNA samples contained Alu-homologous transcripts, mainly in 7-12S fractions and only in one (canonical) orientation. This orientation contained functional regions including promotor region for RNA-polymerase III.

[Analysis of the expression of the c-fos proto-oncogene in the rat cerebral cortex during learning]. / Analiz ékspressii protoonkogena c-fos v kore golovnogo mozga krys pri obuchenii.

Expression of the c-fos proto-oncogene has been associated with mitosis or differentiation in a number of cultured cells or tissues in vivo. Expression of the c-fos proto-oncogene in adult rat brain cells was studied in the process of learning with the use of Northern hybridization techniques. Our results demonstrate that high levels of c-fos mRNA are detectable in brains of all animals treated. Therefore, c-fos is likely to play an important role in the process of learning.

[Analysis of sequences from human brain cDNA gene bank which are functionally active in nervous tissue and tumor cells]. / Analiz posledovatel'nostei, poluchennykh iz banka kDNK mozga cheloveka i aktivno funktsioniruiushchikh v nervnykh i opukholevykh kletkakh.

Construction of a human cortex cDNA bank is described as well as the isolation from this bank of pBH71 and pBH3 clones with preferential expression in nervous and in tumor cells. The clones can be included into the third class of cDNA according to Sutcliff's classification. The mRNA corresponding to this cDNA class is considered to play the key role in determination of specificity of nervous tissue. Expression of the pBH71 sequence was revealed in human cortex and in tissues of different genesis (from neuroblastoma to uterus myoma), a 2 kb mRNA which corresponds to one and the same cDNA chain having been found in all tissues under analysis. The nucleotide sequence of cDNA insertion into the pBH71 clone of 447 n.p. was determined, and particular features of cDNA nucleotide composition and possible schemes of its translation were analysed. Weak homology was found between the 3'-end of cDNA insertion of the pBH71 clone and the 3'-end region of human proopiomelanocortine. The cDNA of the pBH3 clone hybridizes with the 0.8 kb mRNA revealed in human cortex and neuroendocrine tumors of different nature. No homology was revealed between the cDNA sequence of the pBH3 clone and any genes deciphered.

[Two simple methods for isolation of DNA from various sources using cetavlon]. / Dva prostykh metoda vydeleniia DNK iz razlichnykh istochnikov s primeneniem tsetavlona.

Two general methods for the isolation of DNA from various sources based on the use of cetyltrimethylammonium bromide (cetavlon, CTA-Br) are described. Cetavlon is a strong cationic detergent precipitating DNA from diluted salt solutions. Cells are lysed and cellular components are dissolved in the presence of cetavlon, 5 M urea, 0.1 M EDTA and 2 M NaCl (KCl). In the first method pure DNA is precipitated in the form of CTA-salt by direct dilution of the lysate to bring the concentration of NaCl (KCl) down to 0.5 M after the removal of the main part of proteins by deproteinization with chloroform. In the first method pure DNA is precipitated in the form of CTA-salt by direct dilution of the lysate to bring the concentration of NaCl (KCl) down to 0.5 M after the removal of the main part of proteins by deproteinization with chloroform. In the second method DNA is purified on the hydroxyapatite column after cell lysis and the removal of cell debris by centrifugation. Both methods are suitable for rapid isolation of pure DNA from various sources with recovery about 80% and average molecular weight 20-10(6) and higher without use of ribonuclease, pronase and amylase.