Genetical Research

Heavy heat shock induced retrotransposon transposition in Drosophila

a1 Theoretical Department, Institute of Cytology & Genetics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
a2 Department of Cytology & Genetics, Novosibirsk State University, Novosibirsk 630090, Russia


The phenomenon of transposition induction by heavy heat shock (HHS) was studied. Males of a Drosophila isogenic line with a mutation in the major gene radius incompletus (ri) were treated by HHS (37 °C for 1 h followed by 4 °C for 1 h, with the cycle repeated three times) and crossed to untreated females of the same line. The males were crossed 5 d after heat shock, and also 9 d after HHS. Many transpositions were seen in the F1 larvae by in situ hybridization. The rate of induced transposition was at least 2 orders of magnitude greater than that of the control sample, and was estimated to be 0·11 events per transposable element copy per sperm. Two ‘hot’ subdivisions for transpositions, induced probably during the post-meiotic stage of spermiogenesis, were found: 43B and 97DE. Three-quarters of all transpositions were localized in these positions. In other sites the rates of induced transpositions were (1·3–3·2)×10−2 events per occupied segment per sperm, 1 order of magnitude greater than those of the control.

(Received May 26 1997)
(Revised July 20 1998)
(Revised February 25 1999)

c1 Corresponding author. Institute of Cytology & Genetics, 10, Lavrentyev Avenue, Novosibirsk 630090, Russia. Telephone: (7)-(3832)-33-13-66. Fax: (7)-(3832)-33-12-78. e-mail: