Adaptive evolution of low salinity tolerance and hypoosmotic regulation in a euryhaline teleost, Takifugu obscurus

Abstract

Background: The mechanism of osmoregulation is crucial for maintaining growth, development, and life activities in teleosts. Takifugu obscurus, the only euryhaline species in the genus Takifugu, is a proper model organism for studying the mechanism of low salt-tolerance and hypoosmotic regulation. Results: In this study, whole genome sequencing data were obtained from 90 pufferfish representing five species within this genus, T. rubripes, T. obscurus, T. flavidus, T. niphobles, and T. bimaculatus. Using a phylogeny, PCA, and population structure analyses, we observed similar amounts of population genetic differentiation among species. The five species are closely related to each other and have differentiated within a relatively short period, while T. bimaculatus and T. flavidus shared the most similar genetic backgrounds. We further identified hundreds of genes under selection related to hypoosmotic regulation between T. obscurus and other Takifugu species, including 16 representative genes involving ion transporters (atp1a3, atp2a2, atp2a3, slc13a1, slc5a8, slc12a2, slc12a4, slc26a2, scn1b, and kcna2/3/10), genes involved in hormone regulation (fyn, prlr, and grb2), and a gene associated with water absorption (aqp3). Conclusions: Our findings provide preliminary insight into the mechanism of osmoregulation and will facilitate follow-up validation of candidate genes related to osmoregulation in T. obscurus.

Immune and antioxidant responses of pearl oysterPinctada maximaexposed to acute salinity stress

“…In recent years, the impact of changes in salinity on marine organisms has attracted more and more attention. There have been studies about the effects of changes in salinity on the growth, development, life activities, physiological processes and metabolic physiology of marine organisms (Balogh & Byrne, 2021; Zhang, Hou, et al, 2020; Garçon et al, 2021; Tanner et al, 2019; Sun et al, 2021).…”

Application of poultry by‐product meal in diets of obscure pufferfish ( Takifugu obscurus )

“…Obscure pufferfish ( Takifugu obscurus ) is an important aquaculture species in Asia (Wen et al, 2017). In East Asian countries such as China, Japan and Korea, pufferfish are considered as promising species for aquaculture because of the high market acceptance (Zhang et al, 2020). However, the formulation technology for diets of obscure pufferfish was not very mature, and high fish meal levels are still being used (Cui et al, 2021; Yao et al, 2020).…”