The Effects of Some Chemical Residues on the Morphology, Fertility and Enzyme Pattern in the Fruit Fly, Drosophila melanogaster.
Okamoto, D.N.1; Ouchi, R.Y.1; Ceron, C.R.2; Bonilla-Rodriguez, G.O.2
1 Pós graduação em Biologia Animal 2 Departamento de Química e Ciências Ambientais, UNESP – IBILCE campus de São José do Rio Preto-SP
In modern societies, humans may be exposed to a wide variety of environmental chemicals. These sometimes can be toxic, genotoxic or carcinogenic. Although the health significance of this exposure for many chemicals is unknown, studies must be carried out to investigate the potential harmful health effects. The chronic exposure to residues in the laboratory environment concerns due to the unknown toxic capabilities of many chemicals, that could be evaluated by bioindicators. In toxicity studies it is common to use the fruit fly (Drosophila melanogaster) as a model for this kind of study. It is an eukaryotic organism, inexpensive to maintain, its entire genome has been completely sequenced, there are thousands of genetic mutation available for study, it undergoes a short life cycle and the embryos develop in six or seven days in a insect mold. The chosen chemical products to test are coomassie-brilliant blue G250, acrylamide, aluminum chloride, potassium bichromate and lead nitrate. Acrylamide is a laboratory chemical used for gel electrophoresis, it does not occur naturally. The heavy metals studied are highly toxic, bioaccumulative and in general they are neurotoxic. Much of the damage produced by toxic metals is due to the proliferation of oxidative free radicals that they cause. Coomassie is a protein stain used for electrophoresis and does not require MSDS. The offspring of 12 fruit flies couples (in triplicate) is exposed to 50 mM of these chemicals mixed to the culture media, and we analyze the accumulative effect through 10 generations. A control group (also in triplicate) is fed with uncontaminated culture medium. The electrophoretic analysis of 6-esterase, superoxide dismutase and catalase did not show a clear pattern of alteration. For the fertility and morphological analysis the flies were observed and counted every day. The study shows, up to here (F4), that the offspring of the control group is smaller than the test groups, but each chemical modifies the hatching pattern in a singular manner. However, the number of phenotype abnormalities in the treatment group is greater than for the control group. Seems that these differences tend to decrease along with the generations, suggesting active defense mechanisms. Financial Support: FAPESP (05/02418-6) and CNPq.
|