Copy number and distribution of P and I mobile elements inDrosophila melanogasterpopulations

✍ Scribed by Stéphane Ronsseray; Monique Lehmann; Dominique Anxolabéhère

• Publisher: Springer
• Year: 1989
• Tongue: English
• Weight: 876 KB
• Volume: 98
• Category: Article
• ISSN: 0009-5915
• DOI: 10.1007/bf00329685

✦ Synopsis

The distribution of the number of copies of P and I transposable elements per genome was investigated by in situ hybridization for a large set of Drosophila melanogaster strains. These included the P, Q and M' types of the P-M system of hybrid dysgenesis. P element copy number varied widely (range 5-59). P and Q strains had around 40 copies whereas M' strains generally had lower numbers (between 5 and 35) with one extreme value (52). The copy number of I elements appeared to be precisely regulated, as no strains were found outside the 15 +/- 5 range. The number of copies of the two families were independent. An excess of P copies on the X chromosome compared with the autosomes was found for the P and Q strains, but not for M' strains. Among X-inserted P sites, a very high frequency of occupation was found at the tip of the X chromosome (cytological site 1A), especially for P and Q strains. The possible regulatory role in the P-M system of X-inserted P sites is discussed.