Chronic heat stress condition affected many physiological and behavioral mechanisms. Epigenetic alteration after a long time cyclic heat stress exposure, opens new avenues for molecular and biological researchers. One of these changes is monoamines such as serotonin, epinephrine, norepinephrine , dopamine and their transmission. Broilers are very susceptible to heat stress as well as their heart become insufficient during peak of growth period and consequently developed to left heart hypertrophy. RNA-seq Data were obtained from NCBI’s with accession number SRP082125. The expression level of genes was determined by DESeq2 packages. Gene ontology qualification including biological processes (BP), cellular component (CC), and molecular role (MF) was achieved from Gene Ontology Resource. Broiler cyclic heat stress exposure led to significant alteration in monoamine receptors expression. 29 genes of monoamines pathway changed their expression in left heart. Significant down regulation expression statistically was related to ADRB1, HTR2A, PNMT genes and up regulation of MAOA gene (P<0.01). STRING database was used to construct the protein–protein interaction network, based on network analysis, HTR2C, HTR2A and HTR5A genes were figured out the most important hub genes in the network, after that MAOA, DRD2, DRD5, HTR1B, DRD1, DRD3 and HTR2B genes take second important place in network module. In conclusion heat stress treatment prevented heart hypertrophy and altered monoamines genes expression. That would be told monoamines transmission had significant role in heart hypertrophy development and cyclic-chronic heat treatment modulated heart monoaminergic system. These molecular biomarkers may be suitable for screening, diagnosis and treatment heart hypertrophy.
