Decoding the hub gene blueprint for broiler liver development: A synergistic histomorphological and transcriptomic investigation during the neonatal phase

To investigate the morphological transitions and the role of hub genes during the first week of liver development in broilers. At hatch (D0) and 7 days post-hatch (D7), five broiler chickens were humanely euthanized and liver samples were collected to assess liver histomorphology and index. The gene expression data of liver of broilers at D0 and D7 obtained from the GEO database. Differentially expressed genes (DEG) analyses were conducted using GEO2R. Function enrichment for DEGs was conducted using the DAVID and PANTHER databases. Hub genes were identified using the CytoHubba plugin in Cytoscape, employing four different methods: Degree, MCC, ENC, and Closeness. Statistical analyses were conducted using IBM SPSS Statistics. We observed significant developmental changes: liver weight surged by 250.69% (P < 0.01), accompanied by a 75.85% rise in the liver index (P < 0.01). In addition, the histological examination from D0 to D7 reveals distinct morphological transformations. Transcriptomic profiling revealed 1,762 DEGs, comprising 974 up-regulated and 788 down-regulated candidates. Functional enrichment analysis suggested that DEGs participated in fatty acid synthesis and metabolism, cholesterol metabolic process, mitotic cell cycle, as well as MAPK, PPAR, steroid biosynthesis, and metabolic signaling pathway. Notably, six downregulated hub genes (e.g., KIF11 and MCM2) were identified as central regulators of liver maturation. Functional enrichment analysis revealed their pivotal roles in core biological processes-such as double-strand break repair, DNA replication initiation, and mitotic cell division-as well as critical pathways including cell cycle, DNA replication, and cellular senescence. These findings establish hub genes coordinates liver morphogenesis, providing mechanistic insights for optimizing poultry liver health and nutritional strategies.