Insights into the role of three Endonuclease III enzymes for oxidative stress resistance in the extremely radiation resistant bacterium .

The extremely radiation and desiccation resistant bacterium possesses three genes encoding Endonuclease III-like enzymes (DrEndoIII1, DrEndoIII2, DrEndoIII3). enzymatic activity measurements revealed that DrEndoIII2 is the main Endonuclease III in this organism, while DrEndoIII1 and 3 possess unusual and, so far, no detectable EndoIII activity, respectively. In order to understand the role of these enzymes at a cellular level, DrEndoIII knockout mutants were constructed and subjected to various oxidative stress related conditions.

Preference and Motivation Tests for Body Tactile Stimulation in Fish.

We tested whether territorial fish (Nile tilapia) perceive body tactile stimulation as a positive or negative resource. Individual male fish were placed for eight days in an aquarium containing a rectangular PVC frame, which was filled with vertical plastic sticks sided with silicone bristles in the middle of the tank. Fish passing this device received a tactile stimulus.