Transcriptome Analysis of the Hepatopancreas in the Pacific White Shrimp (Litopenaeus vannamei) under Acute Ammonia Stress

Abstract

In the practical farming of Litopenaeus vannamei, the intensive culture system and environmental pollution usually results in a high concentration of ammonia, which usually brings large detrimental effects to shrimp, such as increasing the susceptibility to pathogens, reducing growth, decreasing osmoregulatory capacity, increasing the molting frequency, and even causing high mortality. However, little information is available on the molecular mechanisms of the detrimental effects of ammonia stress in shrimp. In this study, we performed comparative transcriptome analysis between ammonia-challenged and control groups from the same family of L. vannamei to identify the key genes and pathways response to ammonia stress. The comparative transcriptome analysis identified 136 significantly differentially expressed genes that have high homologies with the known proteins in aquatic species, among which 94 genes are reported potentially related to immune function, and the rest of the genes are involved in apoptosis, growth, molting, and osmoregulation. Fourteen GO terms and 6 KEGG pathways were identified to be significantly changed by ammonia stress. In these GO terms, 13 genes have been studied in aquatic species, and 11 of them were reported potentially involved in immune defense and two genes were related to molting. In the significantly changed KEGG pathways, all the 7 significantly changed genes have been reported in shrimp, and four of them were potentially involved in immune defense and the other three were related to molting, defending toxicity, and osmoregulation, respectively. In addition, majority of the significantly changed genes involved in nitrogen metabolisms that play an important role in reducing ammonia toxicity failed to perform the protection function. The present results have supplied molecular level support for the previous founding of the detrimental effects of ammonia stress in shrimp, which is a prerequisite for better understanding the molecular mechanism of the immunosuppression from ammonia stress.

Transcriptomic response to three osmotic stresses in gills of hybrid tilapia (Oreochromis mossambicus female × O. urolepis hornorum male)

“…Nine pathways were uniquely enriched in salinity stress, such as ECM-receptor interaction, protein processing in endoplasmic reticulum, nitrogen metabolism and arachidonic acid metabolism. Among these pathways, arachidonic acid metabolism playing important role in osmoregulation has been reported in Eriocheir sinensis [32], Litopenaeus vannamei [31], Ruditapes philippinarum [39] and Litopenaeus vannamei [63]. Six KEGG pathways were characteristic enriched in alkalinity stress group.…”

Transcriptomic response to ammonia-N stress in the hepatopancreas of swimming crab Portunus trituberculatus

“…Recently, digital gene expression (DGE) analysis has become an effective and convenient method for monitoring differences in the transcriptomic response of tissues or organs under environmental stress in aquatic crustaceans, such as P. trituberculatus (Lv et al 2013), Eriocheir sinensis (Li et al 2013a;Sun et al 2014), Sinopotamon henanense (Sun et al 2016), Macrobrachium rosenbergii (Rao et al 2015), Procambarus clarkii (Shen et al 2014), Litopenaeus vannamei (Guo et al 2016) and Fenneropenaeus chinensis (Li et al 2013b). Lu et al (2016) performed a comparative transcriptome analysis of the hepatopancreas between controls and an ammoniatreated group of L. vannamei. 136 significantly differentially expressed genes were detected, of which 94 genes were related to the immune response and other genes were related to growth, apoptosis, moulting and osmoregulation.…”

Hypoxia-induced changes in survival, immune response and antioxidant status of the Pacific white shrimp (Litopenaeus vannamei ) fed with graded levels of dietary myo -inositol

“…However, no information has been currently available on relationship between penaeidin expression and hypoxia stress in L. vannamei . In the study of Shekhar, Kiruthika, Rajesh, and Ponniah (), the down‐regulation of penaeidin expression was observed in gill and gut of P. monodon exposed to high salinity stress, indicating that the environmental stress factors, such as ammonia stress and heat shock, could affect the expression of penaeidin gene (Loc et al, ; Lu et al, ). In the present study, compared with the control group, a significant up‐regulation of penaeidin expression was found in hepatopancreas due to the administration of MI (368.8–459.7 mg/kg diet).…”