A science experiment that accidentally created a group of unusually vicious hamsters appears to have highlighted just how little is understood about how biology governs behaviour.
American scientists intended to use Crispr, a gene-editing technique at the forefront of biological research, to modify the temperament of Syrian hamsters, a species often used in the laboratory, by blocking the effects of vasopressin, a regulatory hormone.
Previous research had indicated that vasopressin shapes a variety of social behaviours, including aggression and communication. To investigate further, the scientists deactivated a gene known as AVPR1A in a group of hamsters. This meant that they lacked a receptor that interacts with vasopressin in key regions of the brain.
Immune to the effects of the hormone, the rodents were supposed