**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** RATIONALE: SOME TRAITS OF PIGS ARE DIFFICULT TO IMPROVE BY THE TRADITIONAL ROUTE OF FINDING ANIMALS WITH THE BEST TRAITS AND BREEDING THEM. THESE TRAITS OFTEN ARE NOT CONTROLLED MOSTLY BY GENETICS (THERE IS A LARGE ENVIRONMENTAL INFLUENCE), OR THE TRAIT IS DIFFICULT TO MEASURE ON THE POSSIBLE PARENTS. ONE OF THESE LOW-GENETIC INFLUENCE TRAITS IS DISEASE RESISTANCE. BLOOD SAMPLES ARE PRACTICAL SAMPLES THAT ARE OFTEN USED TO SEARCH FOR MARKERS OF DISEASE RESISTANCE SUCH AS PATTERNS OF GENE EXPRESSION, BUT BLOOD IS VERY COMPLEX AND MANY FACTORS INCLUDING THE CELL COMPOSITION OF THE SAMPLE CAN CONFUSE THE INTERPRETATION OF THE RESULTS. THUS NEW METHODS TO MEASURE DISEASE RESISTANCE USING BLOOD ARE NEEDED.HYPOTHESIS: WE PROPOSE THAT BY CAREFULLY MEASURING THE GENES EXPRESSED IN EVERY CELL COMPONENT OF BLOOD WE CAN BETTER USE BLOOD SAMPLES AS AN ASSAY FOR FINDING ANIMALS WITH INCREASED RESISTANCE TO DISEASE TRAITS.OBJECTIVES: WE WILL FIRST MEASURE GENE EXPRESSION IN ALL KNOWN CELL TYPES IN WHOLE BLOOD OF PIGS UNDER MANY DIFFERENT HEALTHY AND DISEASED CONDITIONS: THE CELL TYPE SIGNATURE. WE WILL THEN TEST WHETHER WE CAN PREDICT THE COMPOSITION OF WHOLE BLOOD BY USING THESE SIGNATURES OF EACH CELL TYPE IN SEVERAL SETS OF NEW SAMPLES, INCLUDING BLOOD SAMPLES FROM A LARGE PIG POPULATION MEASURED FOR DISEASE RESISTANCE. FINALLY, WE WILL USE VALIDATED SIGNATURES OF GENE EXPRESSION TO DEVELOP COST-EFFECTIVE METHODS TO ADJUST RAW WHOLE BLOOD EXPRESSION DATA TO ALLOW BETTER STANDARDIZATION AND COMPARISON ACROSS STUDIES.EXPECTED RESULTS: DETERMINING THE EXPRESSION OF ALL GENES ACROSS ALL KNOWN CELL TYPES IN BLOOD WILL BE IMPORTANT RESOURCE INFORMATION FOR BASIC IMMUNOLOGY STUDIES IN PIGS. WE EXPECT TO FIND THAT ADJUSTING THE DATA FROM WHOLE BLOOD BY CELL TYPE SIGNATURES WILL MORE ACCURATELY MEASURE GENE EXPRESSION AND IMPROVE THE USE OF BLOOD SAMPLES FOR MEASURING DISEASE RESISTANCE IN PIGS. WE FURTHER EXPECT TO CREATE A COST-EFFECTIVE METHOD TO STANDARDIZE GENE EXPRESSION DATA FOR IMPROVED INTERPRETATION AND WIDER USE OF BLOOD SAMPLES IN IMPROVING DISEASE RESISTANCE TRAITS.ANTICIPATED IMPACT: THE RESOURCES ON THE GENE EXPRESSION CATALOG OF EXPRESSED GENES IN EACH CELL TYPE WILL BE VERY VALUABLE FOR IMMUNOLOGICAL STUDIES OF INFECTED PIGS. THE IMPROVED AND STANDARDIZED ASSAYS OF BLOOD GENE EXPRESSION ACROSS MANY SAMPLES WILL ALLOW IMPROVED USE OF BLOOD AS AN ASSAY TO PREDICT PIGS WITH BETTER IMMUNE SYSTEMS. THEREFORE WE ANTICIPATE THAT THESE IMPROVED MEASUREMENTS WILL ALLOW FASTER AND MORE ACCURATE METHODS TO SELECT PIGS FOR IMPROVED RESISTANCE.