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E S Zelentsova

Publications and source records attributed to E S Zelentsova.

13 recordsLinked to original sources
PubMed2003

[The unusual mobile element Penelope and its behavior in distant Drosophila species].

The retroelement Penelope isolated from Drosophila virilis has a very unusual structure and codes for reverse transcriptase and an endonuclease belonging to the UvrC type. As shown previously, Penelope is a key element in induction of the hybrid dysgenesis syndrome described in D. virilis, which also involves mobilization of several unrelated mobile element families. Here we report a successful introduction of Penelope into the D. melanogaster genome by P element-mediated transformation. In the new host genome, Penelope is actively transcribed producing major transcript which coincides with that detected in dysgenic hybrids of D. virilis. In situ hybridization on D. melanogaster polytene chromosomes and Southern blotting revealed multiple transpositions of Penelope in the transformed D. melanogaster strains. We determined the structure of six Penelope copies inserted into D. melanogaster chromosomes. Some transformed D. melanogaster strains showed dysgenesis effects similar to those observed in hybrids from D. virilis dysgenic crosses.

Animals↗
PubMed2000

[Genetic characteristics of the wing mutation Odd(22) and its interaction with alleles of the Delta locus in Drosophila virilis].

The dominant sex-linked semilethal mutation Odd22 was isolated from progeny of a dysgenic cross of Drosophila virilis lines. Flies homozygous, heterozygous, and hemizygous for Odd22 displayed multiple wing defects, including enlargements and gaps on the veins; irregularly thickened, branched, shortened, or completely reduced veins; and cuts on the wing margin. The most remarkable feature of the Odd22 expression was a combination of both an increase and a reduction of the wing vein material simultaneously present in the same wing, which is commonly associated with suppression and hyperfunction, respectively, of genes of the Notch (N) signaling system. Phenotypic analysis revealed the interaction of Odd22 with alleles of the Delta (Dl) locus, which codes for the ligand of the NOTCH receptor. Based on these data, Odd22 was assumed to directly or indirectly affect the activity of the genes involved in Dl-N signaling.

Alleles↗
PubMed1998

[Trans-mobilization of deletion copies of the mdg3 retrotransposon in cultured cells of Drosophila].

A model system was studied that was associated with the selective amplification of shortened copies of the mdg3 retrotransposon in cultured cells of Drosophila melanogaster. While full-length mdg3 is present in all species phylogenetically closely related to D. melanogaster, the distribution of its deletion copy mdg3del was shown to be restricted only to D. melanogaster strains. mdg3del appeared to be amplified in two Drosophila cell lines of different origin. A "generalized" (statistically averaged) sequence of the shortened copy from a cell line Schneider2 was determined. The structure of this copy was shown to be the same as in the other tested strains of Drosophila. In addition to the major deletion involving the reverse transcriptase domain and a part of the ribonuclease H domain, several other deletions, insertions, and point substitutions were also revealed in shortened copies. The population of shortened copies was shown to result from the amplification of a single mdg3del copy in the genome of Schneider2 cells. The results obtained suggest that defective copies of the retrotransposon can be trans-mobilized in cultured cells and that the mechanisms of retroamplification in cell cultures and in an organism are different.

Animals↗
PubMed1982

A cloned unique gene of Drosophila melanogaster contains a repetitive 3' exon whose sequence is present at the 3' ends of many different mRNAs.

We have started a cloned genomic DNA fragment approximately 7 kb long (denoted as H55) from the 7B3-4 region in the X chromosome of Drosophila melanogaster. The major part of the fragment is a single-copy sequence. It directs the synthesis of mRNA that makes up approximately 0.1% of the cytoplasmic poly(A)+ RNA from Drosophila embryos. The H55 gene is split by an intervening sequence, yielding a large single-copy exon and a small repetitive 3' exon represented by hundreds of copies in the genome. This repetitive sequence ("suffix") is also present at the 3' ends of approximately 2% of all cytoplasmic poly(A) chains.

Base Sequence↗
PubMed1980

Clusters containing different mobile dispersed genes in the genome of Drosophila melanogaster.

Ten clones containing the actively transcribed mobile dispersed gene Dm255 and its flanking sequences were selected from the HindIII bank of the Drosophila melanogaster genome. The Dm225 sequences present in these clones were identical while the flanking sequences were different in all of the clones analysed. Four of them contained, in addition to Dm225, other DNA sequences binding high amounts of cytoplasmic poly(A) + RNA. The properties of these new genes are similar to those of Dm255: they are also actively transcribed, multiple in copies, scattered throughout the genome, and located at varying genome sites which also were scattered throughout the whole genome of D. melanogaster. Thus, different mobile dispersed genes often appear as closely apposing units forming gene clusters in the genome.

Animals↗
PubMedDate not supplied

[Genetic structure of mobile elements of the "Penelope" family in closely related Drosophila species].

Genomic libraries were obtained from species belonging to the "virilis" group of Drosophila. Several copies of Penelope elements were isolated from these libraries by using a D. virilis Penelope clone as a probe. The elements were sequenced, and their structure was determined. The geographical distribution of this family of mobile elements in closely related species of the group was studied in detail. Cytological localization of the elements was also carried out. The high variability observed between different copies of Penelope is probably due to recombination between individual copies. The role of these elements in the evolution of closely related species is discussed.

Animals↗
PubMedDate not supplied

[Structure and evolutionary role of the Penelope mobile element in Drosophila species of the virilis group].

The mobile element Penelope is activated and mobilizes several other transposons in dysgenic crosses in Drosophila virilis. Its structure proved to be complex and to vary greatly in all examined species of the virilis group. Phylogenetic analysis of the reverse transcriptase (RT) domain assigned Penelope to a new branch, rather than to any known family, of LTR-lacking retroelements. Amino acid sequence analysis showed that the C-terminal domain of the Penelope polyprotein is an active endonuclease, which is related to intron-encoded endonucleases and to bacterial repair endonuclease UrvC, and may act as an integras. Retroelements coding for a putative endonuclease that differs from typical integrase have thus far not been known. The N-terminal domain of the Penelope polyprotein was shown to contain a protease with significant homology to HIV-1 protease. Phylogenetic analysis divided the Penelope copies from several virilis species into two subfamilies, one including virtually identical full-length copies, and the other comprising highly divergent defective copies. The results suggest both vertical and horizontal transfer of the element. Possibly, Penelope invasion recurred during evolution and contributed to genome rearrangement in the virilis species. Chromosome aberrations detected in D. virilis, which is now being invaded by Penelope, is direct evidence for this assumption.

Alcohol Dehydrogenase↗