GENOTOXICITY OF 2 ARSENIC COMPOUNDS IN GERM-CELLS AND SOMATIC-CELLS OF DROSOPHILA-MELANOGASTER

Two arsenic compounds, sodium arsenite (NaAsO2) and sodium arsenate (N a2HAsO4), were tested for their possible genotoxicity in germinal and somatic cells of Drosophila melanogaster. For germinal cells, the sex- linked recessive lethal test (SLRLT) and the sex chromosome loss test (SCLT) were used. In both tests, a brood scheme of 2-3-3 days was empl oyed. Two routes of administration were used for the SLRLT: adult mole injection (0.38, 0.77 mM for sodium arsenite; and 0.54, 1.08 mM for s odium arsenate) and larval feeding (0.008, 0.01, 0.02 mM for sodium ar senite; and 0.01, 0.02 mM for sodium arsenate). For the SCLT the compo unds were injected into males. Controls were treated with a solution o f 5% sucrose which was employed as solvent. The somatic mutation and r ecombination test (SMART) was run in the w(+)/w eye assay as well as i n the mwh +/+ flr(3) wing test, employing the standard and insecticide -resistant strains, in both tests, third instar larvae were treated fo r 6 hr with sodium arsenite (0.38, 0.77, 1.15 mM), and sodium arsenate (0.54, 1.34, 2.69 mM). In the SLRLT, both compounds were positive, bu t they were negative in the SCLT. The genotoxicity of both compounds w as localized mainly in somatic cells, in agreement with reports on the carcinogenic potential of arsenical compounds. Sodium arsenite was an order of magnitude more toxic and mutagenic than sodium arsenate. Thi s study confirms the reliability of the Drosophila in vivo system to t est the genotoxicity of environmental compounds. (C) 1995 Wiley-Liss, Inc.