The immune system is exquisitely capable of distinguishing self-tissues from foreign invaders, often with the goals of protecting the former and destroying the latter. This creates a problem for those animals that birth live young following a prolonged pregnancy. How the immune system avoids attacking the embryo that is genetically half foreign has been a central question in immunology for almost 60 years. Using state-of-the-art, high-throughput gene sequencing technology to investigate patterns of gene expression, this project will investigate regulation of the immune system in the pregnant uterus at different time-points during gestation. The model species to be used is the gray short-tailed opossum, a marsupial mammal native to South America. As a marsupial, they are a very distant relative to humans and mice, but still have live birth following a short gestation. Genes identified from sequencing that are candidates for immune regulation will be further investigated by localizing their expression to specific cell types in pregnant tissues. By comparing species such as humans and mice to distant relatives such as opossums, mechanisms that are ancient and conserved, and therefore likely important, will be uncovered. This project will provide a greater understanding of how the immune system is regulated to deal with pregnancy and has potential broader impact on reproductive health. This project also provides outreach to faculty and students at Central New Mexico (CNM) community college. A CNM faculty member and two students will spend each summer in the principal investigator's laboratory working on some aspects of the project. Students for this research opportunity will be chosen with the advice from CNM faculty members. Preference will be given to students who are in the process of transferring to the four-year university setting to give them the opportunity to engage in independent projects with research active faculty.