Bacon, SarahTremblay, KimberlyFink, RachelClark, Emily2018-05-092018-05-092018-05-09http://hdl.handle.net/10166/4632The liver’s function as a filtering organ leaves it vulnerable to toxin- related diseases such as cirrhosis, and cancer. Studying liver development in the murine embryo allows for in vivo investigation of the process in a mammalian system. Insight from this study may lead to development of novel therapies to treat liver disease. Fate mapping has demonstrated that the murine liver begins as two progenitor populations in the definitive endoderm, when the embryo has 4-6 somites. These precursor cells contribute differently to the liver, and RNA sequencing has identified genes that are differentially expressed between these populations. We sought to further confirm the transcriptional differences between the two populations and probe later expression during development using whole mount in situ hybridization (WISH). This technique allows for reliable visualization of tissues expressing the gene of interest. Although these genes were initially identified as endoderm specific, many were present in other tissues. Interestingly, 20% showed apparent endothelial expression throughout early development.  Of these genes, few showed endothelial cell expression in major vessels; instead expression was more likely to be found in vessels proximal to gut organs. These results suggest a more complex relationship between the endoderm and endothelial cells than previously assumed.en-USLiverdevelopmentmousemurinewhole mount in situ hybridizationin situ hybridizationendothelial cellshepatoblastsThesisrestricted