Transcriptomic analysis provides insight into the mechanism of salinity adjustment in swimming crab Portunus trituberculatus

Multi-omic approach provides insights into osmoregulation and osmoconformation of the crab Scylla paramamosain

“…In contrast, under low salinity exposure, although some amino acid metabolism genes also show differential expression, amino acid metabolism is not among the top enriched pathways in response to low salinity. This finding is consistent with results from previous studies 12 , 16 , suggesting amino acid metabolism plays a minor role in adaptation to low salinity as compared to its role in osmoconforming crabs in high salinity waters. In brief, through focusing on the molecular mechanisms of crab osmoconformation for the first time, we demonstrate the role of amino acid metabolism and transport genes in the process.…”

“…Its downregulation indicates that mud crabs may decrease water uptake from the environment in order to avoid decrease of hemolymph osmolarity during low salinity acclimation. Interestingly, the expression of the Na + /K + ATPase (NKA) remained unchanged in crab gills at all salinities tested in the present study, while it has been shown to play important roles in ion uptake of crustaceans and fishes, usually with increased expression under low salinity 11 , 16 , 29 , 33 , 40 . As NKA expression could vary with time 12 , 41 , a thorough study on its expression with more time points would help to elucidate its role in osmoregulation of the mud crabs.…”

“…Of them, VAT generates a H + gradient across the apical membrane, which enables cations, such as Na + to be transported into the cell via other transporters 28 , and thus critical for hyper-osmoregulation of crustaceans 29 – 31 . VAT usually shows elevated expression during low salinity stress in crustaceans, including the copepod Eurytemora affinis 31 , crabs Portunus trituberculatus 16 , Eriocheir sinensis 15 and Chasmagnathus granulatus 32 , as well as the shrimp Litopenaeus vannamei 33 , indicating that its function is conserved among crustaceans. However, the responses of VAT to salinity stress are different among fishes, indicating its diverse function.…”

“…Besides ion transport, osmotic signal transduction is also important in the molecular mechanisms of osmoregulation in fish 19 – 21 , but this aspect is seldom explored in crustaceans. Although several studies touch upon osmotic signal transduction, they each focus on different genes 13 , 16 , 42 , 43 , such as integrin, crustacean hyperglycemic hormone and 14-3-3 like protein. Among these genes, only integrin showed differential expression in the present study.…”

“…Although several studies mention osmotic signal transduction, they each discuss different genes. For example, integrin was reported to be involved in hyper-osmoregulation of C. maenas , while crustacean hyperglycemic hormone was reported as a mediator of osmotic signal transduction in Portunus trituberculatus 13 , 16 . The unstructured nature of literature on crab osmoregulation suggests that a comprehensive investigation on osmoregulation and osmoconforming mechanisms of brachyuran crabs is still pending.…”