The steps of reverse transcription of drosophila mobile dispersed genetic elements and U3-R-U5 structure of their LTRs

Gypsy transposition correlates with the production of a retroviral envelope-like protein under the tissue-specific control of the Drosophila flamenco gene

“…The RI-adaptor primer was then used in two successive nested PCR reactions combined first with the spliced El -E2 oligonucleotide (see Materials and methods) and then with the 5776-5797 primer. The length and the ClaI-EcoRI restriction map of the major PCR products were consistent with the 3' exon being co-linear with the corresponding portion of the genomic RNA up to the usual termination site (Arkhipova et al, 1986). That the spliced RNA has actually the same 3' end as the 7 kb transcript was confirmed by subcloning and sequencing the ClaI-EcoRI fragment of the PCR product (data not shown).…”

“…Its sequence is organized as a central coding region flanked by two long terminal repeats (LTRs) (Bayev et al, 1984;Freund and Meselson, 1984;Marlor et al, 1986). Gypsy LTRs contain the initiation and termination signals necessary for the production of a terminally redundant genomic RNA (Arkhipova et al, 1986), and are flanked by the tRNA primer binding site and the purine-rich sequence necessary for initiation of DNA synthesis. Most of the RT DNA intermediates have been described in D.melanogaster culture cells (Arkhipova et al, 1986), showing that The schematic drawing shows the unspliced genomic RNA as well as the spliced mRNA.…”

“…Gypsy LTRs contain the initiation and termination signals necessary for the production of a terminally redundant genomic RNA (Arkhipova et al, 1986), and are flanked by the tRNA primer binding site and the purine-rich sequence necessary for initiation of DNA synthesis. Most of the RT DNA intermediates have been described in D.melanogaster culture cells (Arkhipova et al, 1986), showing that The schematic drawing shows the unspliced genomic RNA as well as the spliced mRNA. Numbers refer to the nucleotides at the transcription start site, the splicing donor and acceptor sites, and the transcription termination site.…”

Retrotransposon transposition intermediates are encapsidated into virus‐like particles

“…Electrophoresis under native conditions showed that VLP nucleic acids primarily consist of DNA-RNA hybrid molecules. Treatment of VLP nucleic acids either with RNase at low ionic strength or NaOH increases the mobility of the DNA components of hybrid molecules, and hence the band corresponding to the mobility of single-stranded DNA appeared after hybridization ( fig.2, lanes 4,5), Thus, analysis of VLP nucleic acids showed that all of the retrotransposon transposition intermediates isolated earlier from intact cells [6,7] might also be detected in VLPs.…”

“…pDm58 plasmid was used as mdgl probe and pDm86 as mdg3 probe [6], pDmll1 as gypsy probe [7], and the 252 bp EcoRI fragment of mdgl LTR cloned in pUCl9 (gift from V.A. Gvozdev) was used as LTR-specific probe and for strandspecific probes.…”