Mobilization of the transposable element mdg4 by hybrid dysgenesis generates a family of unstable cut mutations in Drosophila melanogaster

✍ Scribed by Gerasimova, Tatiana I. ;Ilyin, Yurii V. ;Mizrokhi, Lev J. ;Semjonova, Liliya V. ;Georgiev, Georgii P.

• Publisher: Springer
• Year: 1984
• Tongue: English
• Weight: 676 KB
• Volume: 193
• Category: Article
• ISSN: 0026-8925
• DOI: 10.1007/bf00382088

✦ Synopsis

A family of unstable mutations at the cut locus in Drosophila melanogaster was obtained under the conditions of hybrid dysgenesis (Gerasimova 1981(Gerasimova , 1982)). The in situ hybridization experiments have shown that, in the original unstable ct Msz mutation, the 7B region of the X chromosome (where cut is located) contains a mobile dispersed genetic element, mdg4. All other unstable ct mutations derived from ct Ma2 including visible and lethal alleles and unstable ct ~ reversions, also contain mdg4 in the 7B region. The X chromosomes of the parent strain (wild type) do not contain mdg4 at all. All stable revertants derived from ct Ma2, from other unstable ct mutations, or from ct lethals lost mdg4 from the 7B region. The ct MR2 X chromosome does not contain P-elements, although a few copies are present in the autosomes. The instability of the ctMRZ./ ct Ma2 strain remained at a high level for ~ 50 generations (~ 1.5 years) and then rapidly decreased. A new cross with an MRhI2/Cy strain (originally used for dysgenesis induction and containing a number of P-elements) increased the instability to a level exceeding the original one. The data strongly suggest that unstable ct mutations in our system are induced by transpositions of mdg4, possibly activated by P-elements.