Project Grant F32AI202941

GENOMIC REGULATION OF TRANSPOSON-MEDIATED HORIZONTAL GENE TRANSFER IN THE FUNGAL PATHOGEN ASPERGILLUS FUMIGATUS - PROJECT SUMMARY/ABSTRACT HORIZONTAL GENE TRANSFER (HGT) IS A MAJOR DRIVER OF PATHOGEN EVOLUTION AND THE DEVELOPMENT OF ANTIMICROBIAL RESISTANCE, BUT THE MOLECULAR MECHANISM OF HGT AND ITS CONTRIBUTION TO FUNGAL PATHOGENESIS IS POORLY UNDERSTOOD. ONE SYSTEM OF FUNGAL HGT IS THROUGH THE ACTIVITY OF GIANT STARSHIP TRANSPOSABLE ELEMENTS. THESE UNIQUE TRANSPOSABLE ELEMENTS CARRY DOZENS OF GENES, MANY OF WHICH ARE RELEVANT TO VIRULENCE AND STRESS ADAPTATION. STARSHIPS ACTIVELY TRANSFER BETWEEN FUNGI IN THE LAB, MAKING THEM THE IDEAL MODEL SYSTEM TO CHARACTERIZE HGT IN FUNGI. AT LEAST 20 STARSHIPS ARE PRESENT ACROSS ISOLATES OF THE FUNGAL PATHOGEN ASPERGILLUS FUMIGATUS, THE CAUSATIVE AGENT OF INVASIVE ASPERGILLOSIS. INVASIVE ASPERGILLOSIS IS ASSOCIATED WITH APPROXIMATELY TWO MILLION CASES PER YEAR WITH A 72% MORTALITY RATE. ISOLATES OF A. FUMIGATUS VARY GREATLY IN GENETIC CONTENT AND PHENOTYPIC TRAITS SUCH AS RESISTANCE TO HOST STRESSORS AND ANTIFUNGAL TREATMENT. THUS, THE OVERALL GOAL OF THIS PROPOSAL IS TO CHARACTERIZE THE REGULATION OF STARSHIP-MEDIATED HGT AND ITS INFLUENCE ON THE A. FUMIGATUS GENOME AND EPIGENOME. I HYPOTHESIZE THAT STARSHIPS CONFER A CONTEXT-DEPENDENT FITNESS ADVANTAGE AND ARE CONDITIONALLY STIMULATED TO TRANSFER INTO NEW STRAINS WHERE THEY ENACT MAJOR CHANGES TO THE GENOME ARCHITECTURE. TO ADDRESS MY HYPOTHESIS, I WILL IDENTIFY REGULATORS OF HGT AND PROFILE THE INFLUENCE OF STARSHIPS ON RECIPIENT GENOMES. THROUGH A NOVEL IN-LAB HGT ASSAY, I WILL CHARACTERIZE REAL-TIME DYNAMICS OF HGT AND INTEGRATE EPIGENOMIC, TRANSCRIPTOMIC, AND PROTEOMIC APPROACHES TO FURTHER OUR UNDERSTANDING OF STARSHIP BIOLOGY. IN AIM 1, I WILL REVEAL CONDITIONS THAT TRIGGER STARSHIP SELF-EXCISION, THE SPECIFIC REGULATORS DRIVING EXCISION, AND THE CONTRIBUTION OF STARSHIPS TO OVERALL FITNESS. FOR AIM 2, I WILL DISSECT THE IMPACT OF STARSHIPS ON GENOME STRUCTURE POST-TRANSFER AND WILL UNCOVER STRAIN VARIATION IN STARSHIP EXPRESSION AND REGULATION. AS ONE OF THE FIRST MECHANISTIC STUDIES OF STARSHIPS SINCE THEIR RECENT DISCOVERY, THIS RESEARCH WILL CREATE A FOUNDATION FOR OUR UNDERSTANDING OF STARSHIPS ACROSS CLINICALLY RELEVANT FUNGI. THIS RESEARCH IN A. FUMIGATUS HAS NUMEROUS IMPLICATIONS FOR MANAGING INFECTIONS, LIMITING THE SPREAD OF VIRULENCE AND DRUG RESISTANCE GENES, AND DEVELOPING NOVEL SYNTHETIC BIOLOGY TOOLS TO TARGET FUNGAL PATHOGENS.