NEURONAL AND BEHAVIORAL-DIFFERENCES BETWEEN MUS-MUSCULUS-DOMESTICUS (C57BL 6JBY) AND MUS MUSCULUS CASTANEUS (CAST/EI)/

Previous studies have demonstrated that classical inbred strains of la boratory mice do not exhibit large genetic distances when simple seque nce repeats (SSRs) are used to test for their polymorphisms whereas mi ce from wild origin exhibit high polymorphisms (more than 90%) for the se sequence when compared with classical inbred strains of laboratory mice. The difference between Mus musculus castaneus and C57BL/6J reach es 98% and F(1)s male and female are fertile. These two properties pav e the way for gene mapping derivating segregating generations between these strains. The phenotypical characteristics of Mus musculus castan eus have not been investigated, unfortunately. The first screening of Mus musculus castaneus and C57BL/6By was carried out for sensorial and motor development, spontaneous behavior in new environment, paw prefe rence, maternal behavior, aggression in two different situations and t ime to learn escape in a water maze. Morphometry of hippocampus and we ight of the male reproductive organs for measures that have been repor ted to be correlated with several of the examined behavior are also re ported. The authors tested also reactivity to one drug (beta-CCM) reve aling seizure proneness. The two strains differ for 69% of the reporte d measures. Comparison to other strains for the same measures obtained in the laboratory for identical tests with mice reared in identical s ituations provided the mean to compare Mus musculus castaneus with a l arge set of more or less traditional mice. This strain has the most ex treme position for 80% of the comparisons. (C) 1998 Elsevier Science B .V. All rights reserved.