Gene and protein expression during anoxia in crucian carp heart and brain

Anoxia related diseases like stroke and heart infarction are among the most common causes of death and debilitation in humans. The crucian carp (norsk karuss, latin Carassius carassius) is unique among vertebrates in that it can survive without oxygen (anoxia) for several months. This is an adaptation to life in small lakes and ponds in Northern Europe that get ice and snow covered in the winter resulting in oxygen free water. Thus, in nature crucian carp are exposed naturally to anoxia for several months every winter. So anoxia is a natural physiological condition for this species. In the laboratory we have seen that it tolerates at least two weeks of anoxia at 8°C without increased mortality. We use this fish as a model for finding mechanisms that promote anoxia tolerance. In the present project we are interested in how brain and heart in crucian carp defend themselves against anoxic damage and we will therefore measure the expression (mRNA and protein) of key components in brain and heart of crucian carp, making a comparison between normoxia and anoxia. A special focus will be on genes we have found to be changing an a transcriptome study we have done previously. Crucian carp are collected (nylon cages - ruse) in a local pond near Oslo (This fish is very common and locally considered an invasive species in Norway). The fish will be exposed to anoxia under dark conditions (mimicking the situation in nature) for one week (at ca 8°C) followed by reoxygenation of the water for one week. After stunning the fish, brain and heart are rapidly removed and no surgical procedures are involved.