Integrated multi-tissue transcriptomic analysis identifies hub genes associated with egg production recovery after fasting-induced molting.

Fasting-induced molting is widely employed in the poultry industry to rejuvenate the reproductive system of aging laying hens, thereby improving post-molt laying performance and extending productive lifespan. However, substantial individual variation in post-molt reproductive recovery may compromise the overall effectiveness of molting programs. Elucidating the molecular basis underlying this variation is therefore important for poultry production and genetic improvement. In this study, laying hens were classified into high-recovery (HR) and low-recovery (LR) groups according to their egg production recovery following fasting-induced molting. Transcriptomic profiling of the hypothalamus, pituitary, ovary, and liver was performed using RNA sequencing (RNA-seq). A total of 271, 435, 3,425, and 289 differentially expressed genes (DEGs) were identified between the HR and LR groups in the hypothalamus, pituitary, ovary, and liver, respectively. Functional enrichment analysis showed that these DEGs were primarily associated with protein homeostasis, hormone response, ribosome function, and immune regulation, indicating distinct tissue-specific biological functions during post-molt recovery. Integration of weighted gene co-expression network analysis (WGCNA) and protein-protein interaction (PPI) network analysis further identified HSP90AA1, GDF7, CTSS, and STS as candidate hub genes associated with post-molt reproductive recovery. Collectively, this study provides a comprehensive multi-tissue transcriptomic landscape of post-molt egg production recovery and identifies key biological processes and candidate genes potentially involved in this process. These findings improve our understanding of the molecular mechanisms underlying post-molt reproductive recovery and provide valuable genetic resources for the genetic improvement of laying hens with superior post-molt performance.