"Ex-Ovo Chicken Culturing: The Effect Ethanol and Vessel Shape have on the Development of the Chick Embryo"
Dr. Mary Ann Yang
Scientists have been growing chicks outside of eggshells (ex-ovo) for decades. Our goal is to use the chick embryo model to serve as a platform for testing the ability of tissue engineering scaffolds to support blood vessel innervation for sustaining growth after implantation. While growing chick embryos ex-ovo, we noted a failure in closure of the midline of the chick which we now refer to as a ventral body wall deformation (VBWD). Within this study, we propose a hypothesis to the cause of the VBWD being seen in the chick embryos which we are culturing within ex ovo culture vessels. Ethanol has been reported to deter migration of trunk cells in developing embryos resulting in the failure of lateral mesodermal wall closure (Zagory et al, 2004). With this, we hypothesized that the 70% ethanol used to sterilize the vessels is causing the observed VBWD in the chick embryos. Additionally, it was observed that the vessels are shaped significantly different than the natural shape of an egg. We aimed to test if the large circumferential/volumetric space of the ex ovo culture vessel is causing the VBWD in the chick embryo due to failure of the vessel to induce proper pressure of physical constraint during development in comparison to the counterpart of in-ovo incubation.
Chick embryos were cultured in ex-ovo vessels and treated with 250ul of water (control) vs 250ul 30% ethanol (experiment) after 55-56 hours of incubation. Additionally, chicks were cultured in truncated hexagonal pyramid (THP), weighboat, and cube ex ovo vessels. Data shows that ventral wall closure failed in 42.1% of the 19 chicks in the weigh boat with no EtOH, 40.0% of the 20 chicks in the weigh boat with EtOH added, 26.3% of the 19 chicks in the THP vessel with no EtOH, 66.7% of the three chicks in the cube vessel with no EtOH. The rates of VBWD were consistent among both treatment (ethanol) and control chicks leading to the conclusion that ethanol is not responsible for the failure of the lateral mesodermal wall closure. More information and vessel size/shape testing is needed in order to come to a definitive conclusion in regards to whether or not the excess circumferential and volumetric space is the cause of the VBWD.