|Carroll, Jeffery - Jeff Carroll|
Submitted to: American Society of Animal Science Southern Section Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 11/6/2006
Publication Date: N/A
Technical Abstract: Various factors influence age at puberty, such as stress and leptin. Stress delays age at puberty and absence of leptin, or lack of central perception of leptin leads to perpetual sexual immaturity. The environment in which a fetus develops is believed to play a role in the development of various physiological systems. Therefore, in utero exposure to various factors in response to external stimuli, such as maternal stress, could have adverse affects on postnatal growth, and possibly reproductive development. Potential mechanisms involved may include the access of leptin into the brain. Hence, the effect of maternal stress on the age at puberty and Ob-Ra production in the choroid plexus of female progeny was determined. Gestating crossbred sows of similar age and weight were randomly allocated to one of two treatment groups: Control (C) or Stressed (S). S sows were subjected to daily restraint for 5 min during wk 12-16 of gestation. Female offspring were checked twice daily (30 min) for estrus beginning at 122 d of age. On the d of pubertal estrus, blood samples were collected and gilts were euthanized. The choroid plexus was harvested from the lateral, third, and fourth ventricles and analyzed for Ob-Ra expression. Age at first estrus was delayed (P<0.05) in gilts from S sows compared to gilts from C sows (172±6d vs. 158±2d, respectively). Moreover, Ob-Ra mRNA in the choroid plexus was 3.6 fold greater (P<0.001) in pubertal gilts from C sows compared to gilts from S sows. Based on these results, a second experiment was conducted to determine if the difference in Ob-Ra occurred prior to puberty. Hence, gilts from C or Streated sows were euthanized at 2,3, and 4 months of age for Ob-Ra analysis in the choroid plexus. Beginning at 4 mo of age, differences in Ob-Ra gene expression were detected, tending (P=0.1) to be higher in gilts from C sows than in gilts from S sows. Collectively, these results suggest Ob-Ra production in the choroid plexus may play a role in developmental processes that may be linked to reproduction.