Related Experiment Videos
Effect of mitomycin-C and cyclophosphamide on the polytene chromosomes of Anopheles stephensi (Culicidae:Diptera)
G P Sharma1, R C Sobti, A Chaudhry
1Department of Zoology, Panjab University, Chandigarh, India.
Abstract:
Polytene chromosomes from the salivary glands of the mosquito, Anopheles stephensi, were used to evaluate the mutagenic effect of mitomycin-C and cyclophosphamide. Second instar larvae were treated with 1.4 micrograms/ml of mitomycin-C and 20.7 micrograms/ml of cyclophosphamide separately for 24 h. Polytene chromosome preparations were made from the salivary glands of 4th instar larvae. Mitomycin-C treated stocks showed as many as 46.99 +/- 2.48% aberrations compared with 7.5 +/- 0.80% in the controls. Similarly, cyclophosphamide treated larvae showed the aberrated cells to be 36.65 +/- 1.45% as against 7.93 +/- 0.52% in the controls. The results were statistically significant (P less than 0.001) for the two antitumour drugs. Both drugs are mutagenic to polytene chromosomes which are sensitive indicators of DNA damage.
Insights
Mitomycin-C and cyclophosphamide are mutagenic, causing significant DNA damage in mosquito polytene chromosomes. These findings highlight the sensitivity of these chromosomes as indicators of genotoxicity.
Area of Science:
- Genetics
- Toxicology
- Entomology
Background:
- Polytene chromosomes are valuable tools for studying chromosomal aberrations.
- Mosquitoes like Anopheles stephensi serve as model organisms in genetic toxicology.
- Antitumor drugs can have genotoxic side effects.
Purpose of the Study:
- To evaluate the mutagenic effects of mitomycin-C and cyclophosphamide.
- To assess the sensitivity of Anopheles stephensi polytene chromosomes to DNA damage.
Main Methods:
- Second instar larvae of Anopheles stephensi were exposed to mitomycin-C and cyclophosphamide.
- Polytene chromosome preparations were analyzed from salivary glands of treated 4th instar larvae.
- Chromosomal aberration rates in treated groups were compared to control groups.
Main Results:
- Mitomycin-C induced 46.99% chromosomal aberrations, significantly higher than controls (7.5%).
- Cyclophosphamide induced 36.65% chromosomal aberrations, significantly higher than controls (7.93%).
- Both drugs demonstrated statistically significant mutagenic effects (P < 0.001).
Conclusions:
- Mitomycin-C and cyclophosphamide exhibit significant mutagenicity.
- Anopheles stephensi polytene chromosomes are sensitive indicators of DNA damage caused by these antitumor drugs.
- The study confirms the genotoxic potential of these commonly used chemotherapeutic agents.