Abstract
Activins, members of transforming growth factor β (TGF-β) superfamily, are pleiotropic cytokines with critical roles in mediating cell proliferation, differentiation, homeostasis, apoptosis and immune response. However, the structural characteristics and specific functions of Activins remain largely unknown in invertebrates. In the present study, an Activin-like ligand Dawdle (Daw) was firstly identified and characterized from mud crab Scylla paramamosain. The obtained cDNA sequence of SpDaw was 2, 196 bp long with a 1, 149 bp open reading fame, which encoded a putative protein of 382 amino acids. The putative SpDaw protein contained a signal peptide, a TGF-β propeptide region and a TGF-β domain. Real-time PCR analysis demonstrated that SpDaw was predominantly expressed at early embryonic development stage and premolt stages, implying its participation in development and growth. Furthermore, SpDaw responded to both Vibro alginolyticus and Poly (I:C) challenges, suggesting the involvement of SpDaw in innate immune responses. Knockdown of SpDaw in vivo dramatically increased the expressions of NF-κB signaling genes and anti-lipopolysaccharide factor (ALF) genes, and the bacteria clearance efficiency was also markedly enhanced in SpDaw-silenced crabs. Moreover, the in vitro experiment further demonstrated that recombinant SpDaw protein could block the increased transcription of IKKs, NF-κBs and ALFs induced by pathogen challenges. Taken together, these results indicated that SpDaw not only participated in development and growth processes but also played an immune-regulatory role in crabs’ innate immunity, which may pave the way for a better understanding of TGF-β superfamily members in crustacean species.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.