Untitled

Abstract

Molecular response of carbohydrate metabolism in Litopenaeus vannamei was evaluated at transcriptional level through quantitative real-time PCR analysis. The mRNA expressions of six genes hexose-6-phosphotransferase, pyruvate kinase, phosphoenolpyruvate carboxykinase, crustacean hyperglycemic hormone, glucose transporter and insulin-like growth factors binding protein in the hepatopancreas, muscle, gill and eyestalk were analyzed in shrimp fed different levels of carbohydrate and challenged with acute salinity stress. Among these genes, the relative expression of GLUT1, CHH and IGF-BP in the muscle was lower or nearly the same as the control group regardless of the dietary carbohydrate level. The relative expressions of HK and PK were much higher in the hepatopancreas, muscle, gill and eyestalk at 12 h after salinity stress. The relative expression of PEPCK showed a down-up-down tendency and the expression was much higher in different tissues (except in eyestalk) than in the control from 12 to 24 h after stress. This study indicates that there was no significant dietary carbohydrate regulation in muscle. The glycogen and amino acid in muscle were the main source energy for osmoregulation in L. vannamei when the animals were challenged with acute salinity stress. The muscle and gills were the main osmoregulation organ in shrimp under hypo-saline stress.

Adaptive divergence and underlying mechanisms in response to salinity gradients between two Crassostrea oysters revealed by phenotypic and transcriptomic analyses

“…Our observations between species were reasonable in contrast to the transcriptomic variation of populations within Crassostrea virginica , where two reef‐source populations showed a greater environment effect than genetic effect on gene expression differences in response to different salinity environments (Eierman & Hare, 2016 ). Furthermore, transporters (especially SLCs), taurine metabolism pathway, and pyruvate metabolism pathway enriched in the salinity‐correlated module were in response to salinity gradients, which were supported by those of previous studies (SLCs: Boyle et al, 2015 ; Choi et al, 2003 ; Hoglund et al, 2011 ; Hui et al, 2014 ; Jiang et al, 2020 ; Kurita et al, 2008 ; Li et al, 2021 ; Menchini & Chaudhry, 2019 ; Nakajima et al, 2013 ; Wang et al, 2015 ; Wang et al, 2020 ; Wu et al, 2021 ; Zhou et al, 2018; Taurine: Meng et al, 2013 ; Wu et al, 2021 ; Pyruvate: Derakhshani et al, 2020 ; Gullian et al, 2018 ; Wang, Li, et al, 2017 ). These salinity‐responsive pathways also exhibited divergent responses between two oyster species for their enrichment of DEG sets for the species effect and in species‐correlated modules, emphasizing the role of these mechanisms in the formation of divergence in salinity adaptation between the two species.…”