Interpretive Summary: In vivo investigation of ruminant placenta function and physiology—a review

By: Amelia R Tanner, Victoria C Kennedy, Cameron S Lynch, Taylor K Hord, Quinton A Winger, Paul J Rozance, Russell V Anthony

Optimal placental function is required for offspring to reach their genetic potential in utero, and functional placental insufficiency not only results in increased offspring morbidity and mortality, but can impact production traits long-term. However, assessing placental function in vivo is technically demanding, and robust assessment of placental function requires cannulating both maternal and fetal vasculature in order to obtain arterial and venous blood samples simultaneously under non-stressed/non-anesthetized conditions. While feasible in cattle, this approach has been used more extensively in sheep, providing a thorough understanding of placental nutrient uptake, transport, and utilization in normal and compromised pregnancies. Previously, it has not been feasible to alter the abundance of specific gene products within the ruminant placenta, impairing the direct assessment of “cause and effect” relationships in vivo. However, recently methods have been developed to facilitate RNA interference (RNAi) within the placenta, effectively generating a deficiency in specific gene products, to examine the impact on pregnancy progression and outcome. While in vivo RNAi is feasible in a variety of species, in sheep it is being coupled with the aforementioned approaches assessing in vivo placental function, thereby providing new insight into the ramification of specific gene function within ruminant placenta.

Read the full article on the Journal of Animal Science.