THE STERILE INSECT TECHNIQUE (SIT) IS BASED ON THE PREMISE THAT FACTORY-REARED, IRRADIATED MALES CAN COMPETE FOR MATES WHEN RELEASED AMONGST WILD FEMALES, WITH THESE NON-PRODUCTIVE MATINGS REDUCING THE REPRODUCTIVE OUTPUT OF THE PEST POPULATION. COMPARED TO CHEMICAL-BASED PEST MANAGEMENT PRACTICES, SIT OPERATES ONLY THROUGH SEXUAL REPRODUCTION, MAKING IT EXTREMELY SELECTIVE FOR THE PEST SPECIES. HOWEVER, AREA-WIDE MANAGEMENT OF PESTS USING SIT REQUIRES THE ECONOMICAL MASS-REARING OF INSECTS IN A FACTORY SETTING, TYPICALLY ON THE ORDER OF MILLIONS OR TENS OF MILLIONS OF INDIVIDUALS PER WEEK. THIS IS IMPRACTICAL FOR MOST AGRICULTURAL PEST INSECTS, AND THUS THE BENEFITS OF SIT HAVE BEEN RESTRICTED TO JUST A HANDFUL OF PESTS DESPITE THESE PROGRAMS BEING HIGHLY SUCCESSFUL. NEW APPROACHES THAT COULD BE APPLIED TO COLEOPTERAN PESTS THAT HAVE THE POTENTIAL TO CHANGE PEST BEHAVIOR OR MANAGE PEST REPRODUCTION WITHOUT THE REQUIREMENT FOR LARGE-SCALE MASS REARING CAN NOW BE CONSIDERED BASED ON RECENT BREAKTHROUGHS IN THE DEVELOPMENT OF "GENE DRIVE".THE RECENT DEVELOPMENT OF EFFECTIVE GENE DRIVE TRANSGENES IS TEMPERED BY THE FACT THAT THERE EXISTS NO MEANS TO CONTROL OR RECALL SUCH GENETIC ELEMENTS, MAKING SAFETY TESTING IN RELEVANT ENVIRONMENTS PROBLEMATIC. TRIBOLIUM CASTANEUM IS AN EXTREMELY TRACKABLE GENETIC MODEL ORGANISM, WITH A SEQUENCED GENOME AND MATURE SYSTEMS FOR BOTH TRANSPOSON-BASED AND SITE-SPECIFIC TRANSGENE INTEGRATION. TRIBOLIUM IS ALSO AN IMPORTANT STORED PRODUCT PEST, AND IS CLOSELY RELATED TO MANY OTHER IMPORTANT AGRICULTURAL PESTS. IN THIS PROJECT, WE WILL EVALUATE A TRANSGENE ELIMINATION STRATEGY IN TRIBOLIUM, WHEREBY A TRANSGENE CAN BE PRE-PROGRAMMED TO FIRST DRIVE ITSELF INTO A POPULATION AND THEN REMOVE ITSELF FROM THE POPULATION WITHOUT ANY INTERVENTION. WE WILL CHARACTERIZE PARAMETERS OF THE SELF-ELIMINATION SYSTEM, SUCH AS DIRECT REPEAT LENGTH (OBJECTIVE 1) AND NUMBER AND TYPE OF NUCLEASE TARGETING SITES (OBJECTIVE 2). FINALLY, WE WILL TEST THIS SELF-ELIMINATION STRATEGY IN THE CONTEXT OF AN ACTIVE GENE DRIVE (OBJECTIVE 3). OUR INNOVATIVE APPROACH TAKES ADVANTAGE OF NATURALLY OCCURRING PROCESSES THAT ARE CONSERVED THROUGHOUT EUKARYOTA TO ELIMINATE ALL TRANSGENIC SEQUENCES FOLLOWING POTENTIAL FIELD RELEASES WITH NO NEED FOR REMEDIATION. THUS, WE ANTICIPATE THAT THIS PROJECT WILL DRAMATICALLY ALTER THE NATIONAL AND INTERNATIONAL CONVERSATIONS CONCERNING GENE DRIVE TECHNOLOGY, AND WILL RAISE EXPECTATIONS FOR WHAT IS LIKELY REQUIRED TO EVEN BEGIN THE RISK ASSESSMENT PROCESS FOR GENE DRIVE. THIS PROJECT ALIGNS WITH USDA BRAG PROGRAM AREA: MANAGEMENT PRACTICES TO MINIMIZE ENVIRONMENTAL RISK OF GE ORGANISMS.