** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** ONE OF THE MAIN REASONS FOR ECONOMIC LOSS IN CATTLE IS EMBRYONIC MORTALITY. WHILE MOST RESEARCH HAS FOCUSED ON UNDERSTANDING THE MECHANISMS BEHIND EARLY EMBRYONIC MORTALITY BEFORE DAY 20 OF GESTATION, RECENT REPORTS SHOW THAT SIGNIFICANT LOSS ALSO OCCURS DURING EARLY PLACENTAL DEVELOPMENT AFTER DAY 20 OF GESTATION. THE PROCESS OF PLACENTAL DEVELOPMENT IS COMPLEX, AND ERRORS IN PLACENTAL DEVELOPMENT CAN LEAD TO HIGH LEVELS OF REPRODUCTIVE FAILURE, INCLUDING PREGNANCY LOSS AND SUBOPTIMAL FETAL DEVELOPMENT. THEREFORE, STUDYING THE EARLY PLACENTA CAN HELP DEVELOP STRATEGIES TO IMPROVE REPRODUCTIVE PERFORMANCE IN DOMESTIC SPECIES. HOWEVER, THIS REQUIRES A THOROUGH UNDERSTANDING OF THE MOLECULAR, CELLULAR, HISTOLOGICAL, AND METABOLIC EVENTS THAT UNDERLIE PLACENTAL DEVELOPMENT. THE LONG-TERM GOALS OF THIS RESEARCH ARE TO UNDERSTAND HOW THE PLACENTA DEVELOPS, HOW THE PLACENTA INTERACTS WITH THE UTERUS, AND WHAT CELLS AND WHAT MOLECULES ARE INVOLVED IN THE PROCESS OF PLACENTAL DEVELOPMENT. THE AIM OF THIS APPLICATION IS TO CHARACTERIZE PLACENTAL CELL TYPES IN THE MATERNAL ENDOMETRIUM DURING EARLY STAGES OF DEVELOPMENT IN CATTLE, USING CUTTING-EDGE TECHNIQUES. THIS RESEARCH IS THE NEXT STEP TOWARDS ACHIEVING OUR LONG-TERM GOAL.