** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** CHICKEN EMBRYONIC STEM CELLS (ESC) AND PRIMORDIAL GERM CELLS (PGC) ARE PRECURSORS OF SPERM CELLS AND OVA. THEY ARE ESSENTIAL IN GENOME EDITING, PRECISION BREEDING, CELLULAR ENGINEERING, AND MECHANICAL RESEARCH DURING CHICKEN GROWTH DEVELOPMENT AND REPRODUCTION. HOWEVER, OUR UNDERSTANDING OF THE REGULATIONS REGARDING STEM CELLS IN SEX CONTROL IS STILL LIMITED. CHARACTERIZATION OF EPIGENETIC REGULATION WILL PROVIDE A COMPREHENSIVE VIEW OF THE MOLECULAR MECHANISMS THAT GOVERN SELF-RENEWAL AND LINEAGE COMMITMENT. THIS PROJECT HYPOTHESIZES THAT REGULATORY ELEMENTS EPIGENETICALLY DETERMINE THE PROLIFERATION AND TRANSITION OF CHICKEN ESC TO PGC. THE PROJECT AIMS TO PROVIDE DETAILED FUNCTIONAL REGULATORY ELEMENTS, NCRNAS, CHROMATIN STATUS, AND CRUCIAL MOLECULAR PATHWAYS OF THE CHICKEN EMBRYONIC GERM CELLS. THE VALUABLE INFORMATION WILL HELP US ASCERTAIN THE MECHANISMS OF THE DIFFERENTIATION AND PROLIFERATION OF CHICKEN GERM CELLS. WITH A DEEP UNDERSTANDING OF THE FORMATION OF THE PGC MECHANISMS, WE WILL IMPROVE THE EFFICIENCY OF ESC TRANSITION TO PGCS FOR PRESERVING, REGENERATING, CLONING, AND GENOME EDITING OF POULTRY, THUS ENHANCING POULTRY GENETICS AND BREEDING. WE FORESEE THAT THE PROGRESS MAY FURTHER SHORTEN GENERATION INTERVALS AND IMPROVE CHICKEN GENOME EDITING AND COMPARATIVE GENOMICS, EPIGENETICS, AND SEX CONTROL, THUS GENERATING ENORMOUS BENEFITS FOR POULTRY STAKEHOLDERS. LASTLY, THE DATA FROM THE PROJECT ARE SUBSTANTIALLY COMPLEMENTARY TO THE ANNOTATION OF THE CHICKEN GENOME. THE PROJECT WILL IMPROVE CHICKEN GROWTH AND DEVELOPMENT, GENOME ANNOTATION, AND REPRODUCTIVE EFFICIENCY, WHICH ARE OF SIGNIFICANT INTEREST TO POULTRY SCIENCE RESEARCHERS AND STAKEHOLDERS.