Entering into a symbiotic relationship is not something to be taken lightly. Previously free-living organisms become beholden to each other and have to tolerate invasion of their personal space to accommodate varying degrees of intimacy, especially when one partner lives within the body or even the cells of the other. Symbiosis brings with it so many potential mutual benefits that it has arisen...

The presently available mutagen test systems are no longer receiving critical acclaim by sole virtue of their positive response to ethyl methanesulfonate (EMS). Rather, they are being asked to yield answers to such questions as: how mutagenic is EMS in this system and, given this number, what does it imply relative to the genetic risk of EMS to man? Both of these questions address themselves to...

and singlet oxygen. ROS is also generated in cells by exposure to radiation and chemical carcinogens, Because ROS damages nearby cellular components such as DNA, proteins and lipids in mernbrane, cells must have evolved multiple defense mechanisms to combat the oxidative stress, Enzymes such as catalase or superoxide dismutase detoxify ROS, and low-molecular-weight scavengers such as glutathion...

contaminated environments, illustrating the importance of considering the potential for wild populations to adapt to their local environment, and its implications for environmental management. Furthermore, we investigated the effects of hypoxia, a common stressor in aquatic systems, on the toxicity of model chemicals to fish. Copper toxicity to zebrafish embryos was strongly affected by hypoxia...