RNA-seq reveals changes in the transcriptome of the breast muscle of adult female chickens in response to heat stress

Heat stress has caused significant impacts on the poultry industry globally. Tianjin-monkey Chicken (TM) is a local naked neck chicken genetic resource in China, characterized by its heat stress resistance due to a low feather coverage. We conducted heat stress stimulation tests on TM and a normal feathered chicken (Jingfen No. 6 Layer, JF), and the breast muscle tissues were collected for transcriptome sequencing. A total of 157 differentially expressed genes (DEGs) and 1435 DEGs were respectively obtained from the comparisons of JFN-vs-JFT and TMN-vs-TMT. GO enrichment analysis found that biological process (BP) terms including phospholipid homeostasis, regulation of aggrephagy, positive regulation of aggrephagy, and negative regulation of lipase activity may be closely related to heat stress resistance in JF chickens. While catabolism-related BP terms were mainly enriched for DEGs of TM, such as catabolic process, protein catabolic process and cellular catabolic process. KEGG pathway analysis showed that the MAPK signaling pathway was enriched both in TM and JF with high connectivity. In addition, some pathways with higher connectivity (Metabolic pathways, FoxO signaling pathway, TGF-beta signaling pathway and AMPK signaling pathway) may be closely associated with resistance to heat stress in JF. In Tianjin-monkey Chicken, we also identified several pathways potentially involved in heat stress regulation, including Ubiquitin mediated proteolysis, Autophagy-animal and Regulation of actin cytoskeleton. Protein-Protein Interaction Networks (PPI) for the 24 co-differentially expressed genes revealed four key genes (Klf9, Asb2, Tmem164 and Arrdc2) associated with heat stress both in JF and TM. Our findings will enrich the research on heat stress resistance in chicken skeletal muscle, while also providing a theoretical basis for the genetic improvement of heat stress resistance in chickens.