The network regulation mechanism of the effects of heat stress on the production performance and egg quality of Jinding duck was analyzed by miRNA‒mRNA

Abstract

To explore the differential regulation mechanismof heat stress on the egg production performanceand egg quality of Jinding ducks, 200 Jinding ducks(360-day-old) in good health and with similar body weights and a normal appetite were selected and randomly divided into a control (normal temperature, NT) group (20°C-25°C)anda heat stress (HS) group (32°C-36°C),with 4 replicates in each group and 25 ducks in each replicate. The pretrial period was 1 week, and the formal trial period was 4 weeks. At the end of the 4th week, 12 duck eggs were collected from each replicate to determine egg quality. Pituitary and ovarian tissues of Jinding ducks were collected, transcriptome sequencing was performed to screen differentially expressed miRNAs and mRNAs related to high temperature and heat stress, and a competitive endogenous RNA (ceRNA) regulatory network was constructed. The sequencing data were verified by qRT‒PCR method. The following results were obtained: (1) Compared with the NT group, the HS group had asignificantly lower laying rate, total egg weight, average egg weight, total feed intake, and feed intakeper duck (P< 0.01),an extremelysignificantly higher feed-to-egg ratio (P< 0.01), and a higher mortality rate. (2) Compared with the NT group, the HS group had an extremelysignificantly lower egg weight, egg yolk weight, egg shell weight and eggshell strength (P< 0.01) and an extremely significantly lower yolk ratio and eggshell thickness (P< 0.01, P< 0.05); however,there was no significant difference in theegg shape index, Haugh unit or protein height (P> 0.05). (3) A total of 1974 and 1202 genes were identified in the pituitary and ovary, respectively, and there were 5 significantly differentially expressed miRNAs. The differentially expressed genes were involved in the arginine and proline metabolism pathways, ether lipid metabolism pathway and drug metabolism–cytochrome P450 pathway, whichare speculated to be related to the egg production performance of Jingding ducks under high-temperature heat stress. (4) Novel_221 may target the PRPS1 gene to participate in egg production performance; novel_168 and novel_289 may target PIGW; novel_289 may target Q3MUY2; and novel_289 and novel_208 may target PIGN or genes that may be related to high-temperature heat stress. (5) In pituitary tissue, upregulated novel_141 (centre of the network) formed a regulatory network with HSPB1 and HSP30A, and downregulated novel_366 (centre of the network) formed a regulatory network with the JIP1 gene. In ovarian tissue, downregulated novel_289 (centre of the network) formed a regulatory network with theZSWM7, ABI3 and K1C23 genes, novel_221 formed a regulatory network with the IGF1, BCL7B, SMC6, APOA4, and FARP2 genes, and upregulated novel_40 formed a regulatory network with the HA1FF10 gene. In summary, heat stress affects the production performance and egg quality of Jinding ducks by regulating the secretion of endocrine-related hormones and the release of neurotransmitters as well as the expression of miRNAs and mRNAs in pituitary and ovarian tissues. ThemiRNA‒mRNAregulatory networkprovide a theoretical basis for the molecular mechanism thatregulatethe stress response in pituitary and ovarian tissues, egg quality and production performance under heat stress.