©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 11 (1): 739-745 (2012) Downregulation of hsp22 gene expression in Drosophila melanogaster from sites located near chemical plants L.M. Magdalena 1 , E.C. Coipan 2 , A.F. Vladimirescu 2 , L. Savu 3 , M. Costache 4 and L. Gavrila 1 1 Department of Genetics, University of Bucharest, Bucharest, Romania 2 National Institute of Research, Development for Microbiology and Immunology “Cantacuzino”, Bucharest, Romania 3 Genetic Lab SRL, Bucharest, Romania 4 Department of Biochemistry and Molecular Biology, University of Bucharest, Bucharest, Romania Corresponding author: L.M. Magdalena E-mail: geolamon@yahoo.com / monica@botanic.unibuc.ro Genet. Mol. Res. 11 (1): 739-745 (2012) Received May 27, 2011 Accepted November 23, 2011 Published March 22, 2012 DOI http://dx.doi.org/10.4238/2012.March.22.4 ABSTRACT. A common physiological response of organisms to environmental conditions is variation in gene expression, especially true for genes encoding for heat shock proteins. In insects, this process has been examined for induced heat or cold stress. The putative long- term imprinted/acquired heat shock protein response due to unfriendly environmental conditions has been far less studied. The Drosophila melanogaster hsp22 gene, which has been extensively reviewed as being sensitive to different changing life conditions, was examined by qRT-PCR, using carboxy-X-rhodamine. In the present study, we focused on the detection of hsp22 level of transcription in three D. melanogaster isolates, collected from sites located near different chemical plants in Romania and subjected to one-year adaptation to laboratory conditions. In all isolates, the hsp22 gene expression