2023/10/30 by Qingwu Xin, Li Li, Bangzhe Zhao +9
Agricultural and Biological Sciences · Environmental Science · #Effects of Environmental Stressors on Livestock #Animal Nutrition and Physiology #Physiological and biochemical adaptations
paper · doi:10.1016/j.psj.2023.103255
To explore the differential regulation mechanism of heat stress on the egg production performance and 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) and a 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 wk, and the formal trial period was 4 wk. At the end of the 4th wk, 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 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 a significantly lower laying rate, total egg weight, average egg weight, total feed intake, and feed intake per duck (P < 0.01), an extremely significantly higher feed-to-egg ratio (P < 0.01), and a higher mortality rate. (2) Compared with the NT group, the HS group had an extremely significantly lower egg weight, egg yolk weight, eggshell 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 the egg shape index, Haugh unit or protein height (P > 0.05). (3) A total of 1,974 and 1,202 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, which are speculated to be related to the egg production performance of Jingding ducks under high-temperature heat stress. (4) Novel221 may target the PRPS1 gene to participate in egg production performance; novel168 and novel289 may target PIGW; novel289 may target Q3MUY2; and novel289 and novel208 may target PIGN or genes that may be related to high-temperature heat stress. (5) In pituitary tissue, upregulated novel141 (center of the network) formed a regulatory network with HSPB1 and HSP30A, and downregulated novel366 (center of the network) formed a regulatory network with the JIP1 gene. In ovarian tissue, downregulated novel289 (center of the network) formed a regulatory network with the ZSWM7, ABI3, and K1C23 genes, novel221 formed a regulatory network with the IGF1, BCL7B, SMC6, APOA4, and FARP2 genes, and upregulated novel40 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. The miRNA‒mRNA regulatory network provides a theoretical basis for the molecular mechanism that regulates the stress response in pituitary and ovarian tissues, egg quality, and production performance under heat stress.