Micro and macro genetic damage induced by the insecticide Match in mice genome

ABSTRACT

This work aims to disclosing the capability of the well known insecticide Match N-[2,5-dichloro-4-[1,1,2,3,3,3,-hexafluoro-propoxy]-[phenyl]amino]carbonyl]-2,6- difluorobenzamide [CA] that is widely used for controlling certain fruit and leaf caterpillars in inducing micro and macro DNA damage. To investigate its possible genotoxic effects on mammals, different short term genotoxic bioassays were selected and employed. Micro DNA damage was assayed by dominant lethals assay. Macro DNA damage was evaluated by mice bone marrow chromosomes. The effect of Match upon gene expression of serum protein, development and differentiation of sperms was precisely investigated. The frequency of dominant lethal mutations in female mice sired by males treated by Match was significantly higher than that of the control group. There was also a reduction of fertile matings in females mated 15 and 21 days after treatment of males with Match. Analysis of mice bone-marrow chromosomes showed that Match proved to be a positive clastogenic agent, since significant increases of different types of aberrations [e.g., deletions, fragments, Robertsonian centric fusion] were observed and this result was confirmed by the analysis of micronucleated polychromatic erythrocytes. The results also showed that Match has a capability to interfere with spindle fibers of mice spermatid cells, since a significant number of polyploid cells were obtained. Analysis of electrophoretic pattern of proteins indicated that Match was positive in causing changes in proteins specifically in high molecular protein patterns compared with the negative control group. Significant changes in sperm ultrastructural were observed by employing electron microscope. These changes usually were accompanied by nuclear distortion and abnormal chromatin condensation in addition to alteration in head morphology, size, chromatin content and spermatocytes with pycnotic nucleus and alteration with irregular nuclear envelop. Also, mitochondrial abnormalities were mostly accompanied by defects in axoneme including missing of some peripheral microtubules and more commonly missing of central microtubules. In addition, multinucleate spermatids, abnormal chromatin condensation, rupture of cytoplasmic membrane were also commonly observed. Transmission electron microscopy examination of mice treated with Match also indicate that most severe abnormality was the complete disappearance of one or more of nine - fiber duplets and the disappearance of some outer dense fibers