Effect of embryonic thermal manipulation on gene expression in brain tissues of chicken embryos

This study investigated the transcriptomic effects of embryonic thermal manipulation (ETM) on brain development in White leghorn chicken. Fertilized eggs were incubated under control conditions (37.8 °C, 65% relative humidity, ED0–18) or subjected to ETM conditions (37.8 °C, ED0–12;39.5 °C, ED13–18).RNA sequencing was performed on hypothalamus and whole-brain tissues. Differential expression analysis identified 993 genes in the whole brain and 333 genes in the hypothalamus. Gene Ontology enrichment indicated that whole-brain DEGs were associated with gliogenesis, immune regulation, and cell proliferation, while hypothalamic DEGs were enriched in processes related to neural development, hormone secretion, immune function, and oxidative stress. Overall design: RNA-seq was performed on hypothalamus and whole-brain tissues from embryos of White leghorn chicken at embryonic day 18 (ED18). Fertilized eggs were divided into control (CT) and embryonic thermal manipulation (ETM) groups, with three biological replicates per tissue per group. CT eggs were incubated at 37.8 °C and 65% relative humidity throughout, whereas ETM eggs were exposed to 39.5 °C from ED13 to ED18 and otherwise maintained under control conditions. Total RNA was extracted at ED18, libraries were prepared, and sequencing was conducted on the Illumina NovaSeq X Plus platform.