Functional Morphology of the Placenta in Poeciliopsis prolifica

Students: Aaina Gupta and Paige Haenig
Mentor: Tami Panhuis (OWU Department of Zoology)

In the live-bearing fish Poeciliopsis prolifica, mothers transfer nutrients to their developing embryos using a placenta. To get a better understanding of placental structures involved in this nutrient exchange, we injected a fluorescently labeled glucose molecule into pregnant female fish. After a certain amount of time, we removed the embryos from sacrificed females to determine the location of glucose absorption using fluorescent microscopy. Results are pending modification of the protocol, but will allow us to better understand the relationship between placental function and structure.

Teleost fish in the genus Poeciliopsis (Poeciliidae) give live birth, and in some species successful gestation of the embryo depends on a placental structure for continued maternal provisioning of nutrients. The specific placental features involved in maternal-fetal substance exchange have yet to be determined for Poeciliopsis. Our goal was to perform a functional analysis in P. prolifica that would trace nutrients from mother to embryo, as well as locate specific embryonic structures involved in nutrient absorption. We predicted that nutrients would be absorbed through the embryo surface epithelium of the body proper and/or sac. Research suggests that glucose has been successfully traced from mother to embryo. Using 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)Amino)-2-Deoxyglucose (2-NBDG), a fluorescently labeled glucose molecule, we retro-orbitally injected pregnant females. The ovary and embryos were dissected out of sacrificed females after a predetermined amount of time, and viewed using fluorescent microscopy. Results are pending modification of the protocol. This study will give us a better understanding of the embryonic placental tissues, the relationship between placental function and structure, and enable us to perform comparative studies across Poeciliopsis species in the future.