Relationships between agressive behavior and genetic heterozygosity in the Oldfield mouse, Peromyscus polionotus

Garten, C

1) Relationships between aggressive behavior and population genic heterozygosity were investigated using adult male oldfield mice (Peromyscus polionotus) collected at five mainland and three beach localities in the southeastern USA. 2) Genic heterozygosity was estimated using starch-gel electrophoresis to examine allelic variation at structural loci encoding metabolic and blood proteins. Age, testes weight, and body weight were measured and treated as statistical covariates to relationships between behavior and heterozygosity. Aggressive behavior was measured by matching mice in a neutral arena. 3) In intralocality arena tests, mean accumulated attack time and the number of tests producing a fight increased with increasing mean genic heterozygosity of mainland samples of oldfield mice. Defensive and avoidance behavior was also related to population heterozygosity. 4) In interlocality arena tests, mean social dominance ability, mean success in competition for food, mean approaching, aggressive grooming and attacking increased with increasing heterozygosity of mainland samples of mice. 5) Beach mice do not conform to the pattern of increasing behavioral performance with increasing population heterozygosity observed in mainland oldfield mice. The reasons for their divergence from expected levels of performance are unknown, but existing evidence indicates beach mice are taxonomically different from mainland oldfield mice and selection pressures endemic to island or beach environments may be one cause. 6) It was concluded that (a) relationships between behavior and heterozygosity may be important in maintaining genetic variability in oldfield mouse populations, (b) genic heterozygosity may convey a competitive advantage to oldfield mice in crowded environments, and (c) density-dependent changes in a small mammal population's level of genic heterozygosity may give rise to simultaneous changes in allele frequencies, behavior, and numbers.

Relationships between agressive behavior and genetic heterozygosity in the Oldfield mouse, Peromyscus polionotus

Series