Osmoregulation and osmoconformation are two mechanisms through which aquatic animals adapt to salinity fluctuations. The euryhaline crab Scylla paramamosain, being both an osmoconformer and osmoregulator, is an excellent model organism to investigate salinity adaptation mechanisms in brachyurans. In the present study, we used transcriptomic and proteomic approaches to investigate the response of S. paramamosain to salinity stress. Crabs were transferred from a salinity of 25 ppt to salinities of 5 ppt or 33 ppt for 6 h and 10 days. Data from both approaches revealed that exposure to 5 ppt resulted in upregulation of ion transport and energy metabolism associated genes. Notably, acclimation to low salinity was associated with early changes in gene expression for signal transduction and stress response. In contrast, exposure to 33 ppt resulted in upregulation of genes related to amino acid metabolism, and amino acid transport genes were upregulated only at the early stage of acclimation to this salinity. Our study reveals contrasting mechanisms underlying osmoregulation and osmoconformation within the salinity range of 5–33 ppt in the mud crab, and provides novel candidate genes for osmotic signal transduction, thereby providing insights on understanding the salinity adaptation mechanisms of brachyuran crabs.
Bibliographical noteFunding Information:
The work presented in this paper was supported by grants from the Collaborative Research Fund (project no. C4042-14G) and General Research Fund (project no. 14176317 and 14102718), Research Grants Council, Hong Kong Special Administrative Region, China and the National Natural Science Foundation of China (project no. 41606143). We appreciate Werner P. Veldsman and Yik Lok Chung for their constructive comments on the manuscript. We thank Jizhou Zhang for his help with transcriptome data analysis.
© 2020, The Author(s).