Detection of gamma radiation-induced DNA damage in maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) assessed using the comet assay

Abstract

Purpose: The Deoxyribonucleic Acid (DNA) Comet assay, being a quick, simple, sensitive, reliable and fairly inexpensive method for measuring DNA strand breaks, has been used to assess DNA damage caused by gamma radiation in developmental stages of maize weevil Sitophilus zeamais Motschulsky.

Materials and methods: An analysis of DNA damage following gamma radiation (⁶⁰Cobalt) treatments at a dose of 0.5 and 1.0 kGy (Kilo Gray) has been carried out with cells obtained from the larvae, pupae and adults of S. zeamais.

Results: Gamma radiation induced significant damage at DNA level in the experimental larvae, pupae and adults as manifested by increased strand breaks compared to intact cells from non-irradiated ones. Comet assay revealed that tail length and % tail DNA varied significantly for all developmental stages of S. zeamais.

Conclusions: This study suggests that the comet assay would be a potentially useful tool for detecting DNA damage in insect pest control strategies due to its advantages in the requirement of small numbers of cells per sample and sensitivity in detecting low levels of DNA damage.

Keywords:

• Gamma radiation
• developmental stages
• S. zeamais
• comet assay
• DNA damage