**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** EXCESSIVE FAT ACCRETION CAUSES DECREASED FEED EFFICIENCY, LEADING TO ECONOMIC LOSSES IN THE POULTRY INDUSTRY. DISCOVERY OF NUTRITIONAL, HORMONAL, AND GENETIC FACTORS WHICH INFLUENCE ADIPOSE DEVELOPMENT WILL PROVIDE THE NECESSARY FOUNDATIONAL EVIDENCE TO DEVELOP STRATEGIES FOR IMPROVING PRODUCTION EFFICIENCY. VITAMIN A (AS RETINOL) AND ITS METABOLITE, RETINOIC ACID (RA), REGULATES FAT ACCRETION. MOST IN VIVO STUDIES WITH DIETARY CHALLENGES OR INJECTION OF RA SHOWED A DECREASED FAT ACCRETION RATE BY ACTIVATING BREAKDOWN OF STORED FAT IN MATURE ADIPOCYTES OF ADULT ANIMALS. HOWEVER, OUR PRELIMINARY DATA SHOWED PROMOTION OF PREADIPOCYTE DIFFERENTIATION IN VITRO AND INCREASED FAT ACCRETION DURING EMBRYO DEVELOPMENT BY RA. WE DISCOVERED AN ADIPOSE-SPECIFIC GENE, RETINOL BINDING PROTEIN 7 (RBP7), THAT INCREASES CELLULAR RA CONCENTRATION AND PROMOTES ADIPOCYTE DIFFERENTIATION IN VITRO. THEREFORE, IT IS HYPOTHESIZED THAT RA HAS DUAL FUNCTIONS IN POULTRY: 1) RA PROMOTES ADIPOCYTE DIFFERENTIATIONDURING EMBRYONIC AND EARLY POST-HATCH AGES, AND 2) RA ENHANCES BREAKDOWN STORED FAT IN MATURE ADIPOCYTES, DECREASING FAT ACCRETION IN ADOLESCENT AND MATURE BIRDS. TO TEST OUR HYPOTHESIS, WE WILL PURSUE TWO OBJECTIVES; 1) DEFINE THE CONTRIBUTION OF THE RBP7 GENE TO FAT ACCRETION IN QUAIL VIA A TARGETED GENOME-EDITION IN RBP7 GENE, AND 2) DETERMINE TO WHAT EXTENT CONCENTRATIONS OF RA IN EGGS FOR EMBRYOS AND DIETS FOR CHICKS CHANGE FAT ACCRETION IN BROILERS. OUTCOMES FROM THE PROPOSED STUDIES WILL LEAD TO ESTABLISHING RBP7 AS A GENETIC MARKER FOR SELECTION OF POULTRY BREEDERS WITH LESS FAT AND DEVELOPING DIETARY STRATEGIES WITH RA TO REDUCE ADIPOSE GROWTH AND INCREASE FEED EFFICIENCY.