This marbled crayfish (Marmorkrebs) may become one of the new favourite animals for basic medical research. The reason: All animals are genetically identical. This has been suspected because all are female and produce their offspring without sex. There are no males at all. But even with such a mode of reproduction some variations in the genes are possible, depending on the exact mechanism by which the unfertilized eggs of this crayfish begin to divide and to form a new organism.
This mechanism and the genetic fingerprints of nineteen related animals have been analyzed at Humboldt University in Berlin. The researchers conclude that all offspring of a given marbled crayfish share in fact a hundred percent of their genes.
This is good news for all researchers who study the influence of the environment on organisms. If all genes are identical, any difference must be caused by the conditions of the environment, for instance a new drug that is to be tested. Of course, the marbled crayfish is very different from humans, but so are many other laboratory animals for basic research. Time will tell if this crayfish will really help us for a better understanding of our own genetics and for the development of better drugs.
Wikipedia: Marmorkrebs (in German). The species has been detected 1990 in a German aquarium shop. No English entry yet.
(Picture by Jürgen Schmidt)