A preliminary study on the regulation and impact of unfolded protein response on circadian genes in Litopenaeus vannamei

Abstract

Circadian rhythm serves as an adaptive mechanism to environmental changes and is known to regulate multiple physiological processes, such immune response and metabolism. This study explores how unfolded protein response (UPR) affects circadian rhythm genes and their implications at immune and metabolic systems in Litopenaeus vannamei. Under 12 light-dark cycle conditions, Cry1 (LvCry1), Period (LvPeriod), and Vrille (LvVrille) had the highest expression in the eyestalk, while Timeless (LvTimeless) and Shaggy (LvShaggy) were most expressed in the hepatopancreas and nerve. Tunicamycin (TM) injection activated the shrimp UPR and affect the expression of circadian rhythm genes. The time of expression peak of LvCry1 getting earlier, while LvPeriod or LvTimeless peak phase is left shift; LvVrille expression appears circadian disorder, the expression level decreases and the amplitude is significantly lower than the control group. Further investigation revealed that PERK-eIF2α pathway of UPR system may be crucial for its influence on the circadian rhythm gene expression. Further investigation showed that knocked-down expression of LvTimeless, which was significantly affected by the UPR, combined with transcriptomic analysis uncovered that some metabolic and immune-related genes was significantly affected by circadian rhythm. These results have laid a foundation for us to continue to deeply understand the relationship between environmental stress, circadian rhythm and health in L. vannamei.