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The nature of unstable insertion mutations and reversions in the locus cut of Drosophila melanogaster : molecular mechanism of transposition memory
Author(s) -
Mizrokhi Lev J.,
Obolenkova Ljudmila A.,
Priimägi Andres F.,
Ilyin Yurii V.,
Gerasimova Tatiana I.,
Georgiev Georgii P.
Publication year - 1985
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1985.tb04148.x
Subject(s) - biology , genetics , locus (genetics) , genome , evolutionary biology , library science , gene , computer science
The segment of the locus cut containing the mobile genetic element mdg4 (gypsy) insertions which induce unstable ct MR2 and ct MRpN10 mutations has been cloned. Both mutations depend on the insertion of mdg4 into the same sequence, which coincides with that in ct 6 allele. The ct MRpN10 mutation differs from ct MR2 by additional insertion of a novel mobile element jockey into mdg4. Jockey is 2.8 kb long, represented by ˜2–100 copies per genome, very homogeneous and lacks long terminal repeats (LTRs). The excision of mdg4 takes place in stable ct + reversions. On the other hand, a complete single LTR is retained in the case of unstable ct reversions characterized by a high level of reverse directed transpositions of mdg4 into the locus cut . The LTR serves as a guide for reinsertion of mdg4 itself or mdg4 with jockey into the same site of the genome. A possible mechanism of transposition memory (homologous recombination with extrachromosomal circular DNA) is discussed.