Active maternal phenotype is established before breeding and leads offspring to align growth trajectory outcomes and reflex ontogeny

The main goals of this study were to classify dams according to the level of voluntary physical activity before breeding and during pregnancy/lactation and to evaluate the effects on growth trajectory and reflex ontogenesis of offspring. Voluntary physical activity was ranked by traveled distance, time and daily estimated calorie burned. Thirty-five female Wistar rats were classified as control (C, n = 5), inactive (I, n = 10), active (A, n = 8) and very active (VA, n = 12). During 30 d before breeding, traveled distance, average speed, time and calorie burned were daily recorded for active and very active groups. Traveled distance was recorded each 2 h every day of adaptation. Body weight, food intake and fasting glycemia were measured throughout the experiment. During lactation, litters were evaluated in terms of physical features and reflex ontogeny. VA showed a progressive increase in the traveled distance and time while A dams presented constant values. VA rats showed lower body weight and higher food intake. During pregnancy, both groups performed less than 1 km/day. Pups from A and VA dams showed higher lateral-lateral axis of the skull, longitudinal axis, tail length, and anticipation of the pavilion and auditory canal opening, and erupting incisors. I, A and VA groups showed a delay of righting, cliff aversion and vibrissae placing reflexes. In conclusion, active maternal phenotype is established before breeding allowing mothers to fit ecological and influencing growth trajectory outcomes and reflex ontogeny of the offspring based on matrilineal experience.