[Genetic analysis of predator aggressiveness in mice].

The character of inheritance of mouse predatory aggression towards crickets and locusts was investigated. The percentage of aggressive animals in the group and the latency of attack were indices of aggression. The hybridological analysis included obtaining reciprocal F1 and F2 hybrids and backcrosses of CBA and DD mice lines exhibiting polar parameters in predatory tests. Examination of hybrids and backcrosses showed that the high level of aggressiveness is dominant. Sex differences in aggression were seen neither in parent strains, nor in hybrids, reciprocal effects being also absent. The results of the hybridological analysis indicated that the predatory aggressions are under control of a small number of genes with a pronounced dominant effect. As a result of diallele analysis in three strains of mice, BALB/c, C57BL/6, DD and all combinations of first generation hybrids, it was found that almost all hybrids exhibited greater aggressiveness than that of parent strains or that it was similar to the indices of highly aggressive parents. Analysis of a strain combinative ability showed that the genotypic component is conditioned by a specific combinative ability, the influence of the total combinating ability and of the reciprocal effects being not significant. It was once more confirmed that the predatory aggression in mice is inherited as a high level dominancy of aggression and genes influencing its manifestation are localized in autosomes.