Behavioral Phenotypes of Inbred Mouse Strains :: essays research papers

Molecular geneticists have recently been using targeted gene line mutations so as to effectively isolate certain genes as being the cause of a specific phenotype. However the effects of a gene can be a result of complex interactions within its genetic background. Scientist have tried to maintain and isogenic genetic background. However in choosing the appropriate isogenic background it is important that all of the effects of it be documented so that the appropriate selection of genetic background can be chosen for an expected phenotype and so that the results can be interpreted properly. The effects of different strains on the performance of various different tests of an animal’s behavior are documented here. A well established measure of mouse behavior is open field locomotion. In this measurement a mouse’s amount of movement, rate of movement and other behaviors are measured. These measurements are proposed to suggest specific levels of emotionality and anxiety in mice as well as other underlying traits. The levels of activity and anxiety have been measured for specific strains. The best choice for a strain when trying to assess the level of activity or anxiety for a mutation is the strain that is known to produce the opposite level of anxiety or activity. There are two types of learning tasks that have been assessed for. Complex learning tasks involve and animal using multiple pieces of information simultaneously and Avoidance tasks which involve the animal avoiding a location where they have previously received a shock. Other behavioral traits that have been assessed are aggressiveness, reproductive behavior and the effects of acoustic startle where the reaction of a mouse to a loud noise is measured as well as its reaction when the sound is preceded by a relatively quiet sound The effects of genetic strains have also been studied with regard to their effects on certain drugs. The effects of drugs such as ethanol show that it is very hard to generalize the effects of a specific drug on a specific strain since the reactions vary with the dose given and with the reinforcing effect that it has on the mice. In some studies it was shown that despite the noticeable mean effect of ethanol on a strain it did not have the same effect with a different dose. However certain generalizations of strains sensitivity to ethanol have shown themselves to be robust across several procedural variations.