Liver Dynamic Transcriptomic Response To Heat Stress In Laying Hens

Thermal stress seriously affects the production of poultry industry,significantly reducing layer and broiler production performance.To reduce the negative impact of global warming on poultry production,molecular breeding techniques should be employed to fundamentally improve the host resistibility to heat stress,which depends on the knowledge of host genetic mechanism of thermal stress resistance.In this study,commercial laying hens were performed 35℃ acute heat stress on for 3h for detecting the expression changes of miRNA and mRNA in liver tissue by high-throughput sequencing,resulting in several key molecular pathways induced by heat stress.Also,intergrade analysis were performed miRNA and mRNA expression data,indicating a series of biological changes occurred in liver tissue.The main results are as following:(1)Using mRNA transcriptional sequencing inthe liver tissues,acute heat stress induced 932 genes(p value < 0.01,FDR < 0.1 and fold)with significantly differential expression,of which 339 genes were significantly upregulated and 593 genes were significantly downregulated.(2))The heat shock proteins(HSPsfamily exhibit different expression patterns under the heat stress,resulting in HSP90AB1,HSPA13,HSPA5 significantly downregulated and DNAJC17,DNAJC12 and DNAJB2 significantly upregulated(3)Acute heat stress induced a series of biological processes.It significantly activated the p53 signaling pathway and inhibited the NRF2 mediated oxidative stress pathway and Estrogen mediated cell cycle pathway.(4)Using miRNA sequencing,total 10 differently expressed miRNA(P < 0.01,FDR < 0.1,Fold >2)were induced in the liver tissue by heat stress,including gga-miR-122-3p,gga-miR-3528,gga-miR-193b-3p,gga-miR-214,gga-miR-3536,gga-miR-18a-3p,gga-miR-1467-5p,gga-miR-30c-5p and gga-miR-193a-5p.All of them were significantly reducedafter heat stress.(5)Integrated analysis on the expression of miRNA and mRNA revealed 41 negatively regulated miRNA-mRNA pairs..Among them,gga-miR-193a-5p,gga-miR-214 and gga-miR-3528 corporately regulated ESR2 mediate Estrogen receptor signaling pathway,andgga-miR-3536 and gga-miR-3528 played a role in STAT3 signaling pathway via ESRP2,TGFBR2 and CISH.In conclusion,acute heat stress induced a significant change in liver tissue at the transcriptional level.It mediated mitochondrial abnormalities,oxidative phosphorylation and other molecular pathways through the regulation the expression of ATP5 B,ALDOC and other genes,impacting the calcium and energy metabolism and other processes,and finally affected the egg production performance.This study initially revealed the genetic changes of hens in response to acute heat stress,and provided a novel sight on the genetic mechanism of heat stress resistibility in hens,which will improve the process on breeding the high quality layers with high resistance on heat stress in the future.