The process of porcine conceptus elongation is a critical period of development that highly
influences subsequent conceptus survival and ultimately litter size, piglet birthweight, and
postnatal survival. A thorough understanding of elongation can have extraordinary impacts on
the overall efficiency of swine reproduction and the production of a sustainable source of protein
for the growing world population. Although previous studies have identified some of the
factors contributing to this rapid morphological change of the porcine conceptus, due to the
complexity and difficulty of examining this process in vivo and in vitro, many of the specific
factors and mechanisms influencing this morphological transition remain
unelucidated.

In order to develop a deeper understanding of porcine conceptus elongation, this dissertation investigated
changes to the global transcriptome of the porcine conceptus, as well as to the metabolome of the surrounding uterine environment, throughout the initial morphological stages of elongation through in vivo metabolomic and transcriptomic analyses. These investigations identified potential metabolic changes within the concepts, including amino acid, protein, bile acid, purine, and energy metabolism, as well as potential mechanisms of gene regulation within the conceptus, such as cytokine, growth factor, and lipid signaling, as well as phospholipid membrane, ECM, and adhesion remodeling, that may contribute to the
initiation of porcine conceptus elongation. Further, this dissertation examined changes in the metabolism and secretion of factors by the elongating conceptus invitro utilizing our developed 3D hydrogel culture system, identifying potential RGDindependent and RGD-mediated mechanisms of elongation, such as
phospholipid and sphingolipid metabolism and secretion. Overall, these studies provide further knowledge of the complex factors and mechanisms contributing to this rapid morphological change within the porcine conceptus.