Dystrophin gene expression and intracellular calcium changes in the giant freshwater prawn, Macrobrachium rosenbergii , in response to white spot symptom disease infection

Abstract

BackgroundDystrophin, an essential protein functional in the maintenance of muscle structural integrity is known to be responsible for muscle deterioration during white spot syndrome virus (WSSV) infection among prawn species. Previous studies have shown the upregulation of dystrophin protein in Macrobrachium rosenbergii (the giant freshwater prawn) upon white spot syndrome virus (WSSV) infection. The literature has also suggested the important role of calcium ion alterations in causing such muscle diseases. Thus, the interest of this study lies within the linkage between dystrophin functioning, intracellular calcium and white spot syndrome virus (WSSV) infection condition.MethodsIn this study, the dystrophin gene from M. rosenbergii (MrDys) was first characterised followed by the characterization of dystrophin gene from a closely related shrimp species, Penaeus monodon (PmDys). Dystrophin sequences from different phyla were then used for evolutionary comparison through BLAST analysis, conserved domain analysis and phylogenetic analysis. The changes in mRNA expression levels of dystrophin and the alteration of intracellular calcium concentrations in WSSV infected muscle cells were then studied.ResultsA 1246 base pair long dystrophin sequence was identified in the giant freshwater prawn, Macrobrachium rosenbergii (MrDys) followed by 1082 base pair long dystrophin sequence in P. monodon (PmDys). Four conserved domains were identified from the thirteen dystrophin sequences compared which were classified into 5 different phyla. From the phylogenetic analysis, aside from PmDys, the characterised MrDys was shown to be most similar to the invertebrate phylum of Nematoda. In addition, an initial down-regulation of dystrophin gene expression followed by eventual up-regulation, together with an increase in intracellular calcium concentration [Ca2+]i were shown upon WSSV experimental infection.DiscussionBoth the functionality of the dystrophin protein and the intracellular calcium concentration were affected by WSSV infection which resulted in progressive muscle degeneration. An increased understanding of the role of dystrophin-calcium in MrDys and the interactions between these two components is necessary to prevent or reduce occurrences of muscle degeneration caused by WSSV infection, thereby reducing economic losses in the prawn farming industry from such disease.

Effect of WSSV infection on cell cycle regulation, respiratory burst and cytoplasmic free calcium concentration in Penaeus vannamei

“…For example, sarcoplasmic calcium-binding protein which acts as a buffer to cytosolic Ca 2+ and maintains the intracellular Ca 2+ levels was found to have low expression levels in WSSV-infected P. monodon (Leu et al, 2007). Similarly, downregulation of dystrophin gene expression was attributed to metabolic changes, leading to an increase in Ca 2+ levels and loss of muscular integrity in the WSSV infected muscle tissues in M. rosenbergii (Noor et al, 2017).…”

“…Similar results have been reported in the muscle tissue of the WSSV‐infected M . rosenbergii , which showed a significant increase in the amount of intracellular calcium from 3 hours post WSSV infection, with an overall increase of 1.6‐fold in the infected samples compared with the control samples (Noor et al, 2017). The other factors such as chronic Cu 2+ exposure of P .…”

“…Similarly, downregulation of dystrophin gene expression was attributed to metabolic changes, leading to an increase in Ca 2+ levels and loss of muscular integrity in the WSSV infected muscle tissues in M . rosenbergii (Noor et al, 2017).…”

WSSV exploits AMPK to activate mTORC2 signaling for proliferation by enhancing aerobic glycolysis

“…Some viruses can utilize the host Ca 2+ -associated pathway to promote their replication 31 . Previous research has shown that intracellular calcium increases after WSSV infection and CaMKK is activated by the increased cytoplasmic Ca 2+ 32 . It is unknown whether CaMKK activates AMPK signaling in shrimp.…”

Downregulation of dystrophin expression in pupae of the whitefly Bemisia tabaci inhibits the emergence of adults

“…We have shown previously that silencing genes of the ecdysone synthesis and signalling pathway impaired the development and survival of whitefly nymphs (Luan et al , ). Here we targeted dystrophin (Dys), a conserved protein essential for the development of the muscle system in humans and in many other organisms (Noor et al , ).…”