Abstract # 96:

Scheduled for Friday, June 22, 2012 10:45 AM-11:00 AM: Session 13 (3rd Floor All Space) Oral Presentation


DEVELOPMENTAL CHANGES IN MICROSCOPIC PLACENTAL ARCHITECTURE AND ITS RELATION TO FETAL GROWTH IN THE VERVET MONKEY (CHLOROCEBUS SABAEUS)

J. N. Rutherford and V. A. DeMartelly
University of Illinois at Chicago, Department of Oral Biology, College of Dentistry, 801 S. Paulina Street, Chicago, IL 60612, USA
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     Little is known about placental growth and morphology across gestation in nonhuman primates. A rare time-series of 50 vervet monkey (Chlorocebus sabaeus) placentas from the St. Kitts Biomedical Research Foundation was characterized in terms of gross morphology and shifts in efficiency across the latter half of a species-typical 167-day gestation. Both fetal mass and placental mass increased significantly with gestational age (Pearson’s correlations: R=0.85, P<0.00001; R=0.64, P<0.00001, respectively) but the size of the placenta relative to fetal mass decreased significantly between period 1 (d. 83-130) and period 2 (d. 131-159) (T-test: T=-3.60, P<0.00001). Placental mass accrual slowed at day 130 while fetal mass continued to increase. Though relative placental size decreased between period 1 and period 2, the surface area of the placental villi – the site of nutrient transport from mother to fetus – increased significantly, both in terms of volume (T-test: T=-4.49, P<0.00001) and surface area (T-test: T=-5.33, P<0.00001). This suggests there is an important shift in the metabolic capacity of the placenta, via an expansion of the microscopic surface area of the villi to support the energetic burden of late gestation brain and somatic growth. A better understanding of how the placenta drives and constrains fetal and brain growth in anthropoid primates is thus directly relevant to developmental models of human brain evolution