GENETIC AND DEVELOPMENTAL INFLUENCES ON INFANT MOUSE ULTRASONIC CALLING .1. A DIALLEL ANALYSIS OF THE CALLS OF 3-DAY OLDS

Ultrasonic calls produced by young mice reliably elicit investigation and retrieval by adults. While there are large individual differences in the characteristics of these calls, little work has been done to pa rtition that variation. We completed a 4 x 4 diallel cross and Hayman analyses on several characteristics of these cries. The major result w as the detection of directional dominance toward a higher rate of call ing, longer calls, and calls of lower overall frequency with a greater bandwidth. Within the context of biometrical genetic theory, we concl ude that calls with such characteristics may have important fitness va lue. Extending this idea, we propose that within the population sample d for this study (the animals of the four inbred strains and 12 F-1 hy brid groups), the calls most effectively eliciting investigation and r etrieval would be calls with the average hybrid values of the diallel cross.