Transcriptomic Analysis Reveals Sex-Biased Gene Expression in Duck Turbinate Tissue

Olfaction is crucial for ducks, influencing essential behaviors such as foraging and mating. However, the molecular basis of sex-associated variation in duck olfactory tissues remains poorly understood. Here, we performed bulk RNA-seq on turbinate tissue from male and female Tianfu Nonghua Mottled Ducks (Anas platyrhynchos domesticus Linnaeus, 1758; Anatidae) to characterize sex-biased transcriptional programs. Our results suggest strong global transcriptomic separation between males and females, with 1906 differentially expressed genes (DEGs) identified. These DEGs were enriched in pathways related to neuronal signaling, cell adhesion, and extracellular matrix organization, suggesting coordinated sex-associated differences in signaling and tissue-organization programs. While olfactory receptor (OR) and trace amine-associated receptor (TAAR) genes showed limited sex-biased expression in bulk tissue, two neuromodulatory GPCRs, TACR2 and DRD4, were prioritized as hub genes within sex-biased co-expression networks. Notably, both genes also showed relatively high expression in turbinate tissue and neuroendocrine centers in an integrated multi-tissue transcriptomic dataset, nominating them as candidate targets for future functional and cell-type-resolved investigations. Overall, our study provides a descriptive molecular profile of sex-biased transcription in duck turbinate tissue, laying a foundation for follow-up studies and potential applications in poultry breeding and management.