Heredity, nutrition, and craniofacial differentiation in weanling rats: A multivariate analysis

The effects of paternal heredity, congenital variation, and preweaning nutrition on craniofacial growth were studied on weanling Wistar (W), Holtzman (H), and their reciprocal crosses, W/H and H/W, male rats. Between-group Mahalanobis D² distances were calculated from the measurements made on lateral and vertical X-rays. Preweaning nutrition evoked the largest cranial differences, and paternal heredity the lowest; the effect of congenital variation was intermediate between these extremes. It is concluded that "strain" differences actually are the result of the complex interplay among congenital and lactational factors that can modify the genetic effect due to strain. © 1994 Wiley-Liss, Inc.