Transcriptomic insights into early responses of the uterovaginal junction and vagina to avian influenza virus infection in turkey breeder hens

Avian influenza virus (AIV) infections, even with low-pathogenic strains (LPAIVs), can severely disrupt reproduction in turkey breeder hens. Although the vagina and uterovaginal junction (UVJ) are among the earliest mucosal sites exposed to pathogens, their early transcriptomic responses to LPAIV infection remain poorly understood. This study investigated early transcriptomic changes in these tissues during both presymptomatic and symptomatic stages of LPAIV infection (n = 4 per group per tissue) using high-throughput RNA sequencing. The findings revealed early, tissue-specific molecular vulnerabilities to LPAIV: the UVJ exhibited disruptions in cellular maintenance and metabolism, potentially impairing fertility, while the vaginal response showed early immune activation followed by compromised barrier integrity. These results offer mechanistic insights into LPAIV-induced reproductive pathologies and provide a foundation for developing targeted strategies to reduce viral impact on flock health and maintain production efficiency.