Open AccessMolecular study of the retrovirus-like transposable element 412, a 20-OH ecdysone responsive repetitive sequence inDrosophilacultured cells
Author(s) -
D. Micard,
J.L. Couderc,
Marie-Laure Sobrier,
G Giraud,
B. Dastugue
Publication year - 1988
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/16.2.455
Subject(s) - biology , extrachromosomal dna , drosophila melanogaster , transposable element , ecdysone , polyadenylation , retrovirus , microbiology and biotechnology , long terminal repeat , dna , gene expression , cell culture , genetics , gene , plasmid , genome
Used at a physiological concentration, the steroid hormone 20-hydroxyecdysone (20-OHE) induces, in Kc cultured Drosophila melanogaster cells, important and specific changes. Modifications occur at morphological and enzymatical levels. Variations in specific protein synthesis are observed. At the molecular level, 20-OHE particularly induces a decrease in expression of the mobile dispersed genetic element 412. This repeated element which belongs to the "copia-like" family is more widely represented in Kc cells (80 fold) compared to fly cells (25 fold). 412 transcripts are heterogeneous in size, essentially polyadenylated and restricted to the nucleus. A minimal concentration of 10(-8) M and a time treatment of 16 hours are necessary to obtain a strong decrease in 412 expression. The decrease is at least an effect on these sequences at the transcriptional level. Structural similarities between the 412 element and the proviral forms of vertebrate retroviruses are strengthened by the characterization of extrachromosomal circular DNA forms revealed by the 412 probe. Quantifying experiments have shown that the steady state level of such forms is not affected by the steroid treatment.