Animal and Veterinary Sciences

White spot syndrome virus (WSSV) is the causative agent of a disease which has recently caused high shrimp morbidity, mortality and severe damage to shrimp cultures. In this study a strain of WSSV from tiger shrimp Penaeus monodon was used to detect DNA damage in muscle cells by using Comet Assay. The term "comet" refers to the pattern of DNA migration through the electrophoresis gel, which often resembles a comet. The present results declare that Comet Assay is a rapid, simple, visual and sensitive technique for detecting and analyzing DNA in damaged cells. In WSSV infected shrimps, damaged cells looked like a tiny comet under a microscope. When DNA is broken in infected cells it forms a tail that moves away from the unbroken DNA. The amount of DNA damage in cells was estimated from comet tail length as the extent of migration of the genetic material. Significant increases in intensity percentage of DNA tail portion, tail length and tail moments of infected shrimps were observed in comparison with normal healthy shrimps. Furthermore, the clinical signs of white spot disease were also discussed in this study.