Mutagenesis vol. 18 no. 6 pp. 527-531,
November 2003
© 2003 UK Environmental Mutagen Society/Oxford University Press
Germline mutations induced by N-nitroso-N-ethylurea do not affect the inserted copia retrotransposon in a Drosophila melanogaster wa mutant
Grup de Mutagènesi, Unitat de Genètica, Departament de Genètica i de Microbiologia, Facultat de Ciències, Edifici Cn, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
The white-apricot (wa) mutant of Drosophila melanogaster is characterized by a copia retrotransposon inserted in the second intron of the white locus. After germinal exposure to the alkylating agent N-ethyl-N-nitrosourea, we have obtained new phenotypes in the offspring, mainly lighter eye colour, but not revertants to the original phenotype. Subsequent genetic crosses showed that only 3 out of 13 new mutant phenotypes were allelic. Three white gene regions were analysed by Southern blot in order to determine the nature of the mutations. These three regions were the 5' regulatory region, the copia insertion site and the 3' coding region. The results obtained indicate that the treatment does not induce the total or partial excision of copia in the white locus. Two of the new allelic mutants present a 5' or 3' deletion in the white locus. The other new phenotypes seem to be caused by mutations being induced in other loci acting as modifiers, most of them located on the X chromosome.
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Received on May 8, 2003 revised and accepted on July 24, 2003