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Abstract

Transforming growth factor-beta 1 (TGF-β1) as a member of TGF-β superfamily plays crucial roles in regulation of immune responses. Yellow catfish, Pelteobagrus fulvidraco, is one of the most important freshwater aquaculture species in China, but little is known about its genes related to immune response. The present study cloned cDNA encoding TGF-β1 from P. fulvidraco. The results showed the full-length cDNA of TGF-β1 is 2,816 bp and encodes 461 amino acids. The homology of P. fulvidraco TGF-β1 depicted 83% and 81% similarity to the TGF-β1 in Stegastes partitus and Pundamilia nyererei respectively. The phylogenetic tree construction revealed that P. fulvidraco is closely related to Astyanax mexicanus. Analysis of mRNA expression of TGF-β1 in different tissues (gonads, brain, liver, kidney, spleen, intestine, blood, gills, muscle and heart) revealed that TGF-β1 is predominantly expressed in liver and brain, followed by gill and spleen. TGF-β1 gene in gill and spleen up-regulated for 48h after Edwardsiella ictaluri and Flavobacterium columnare injection, then the expression showed a significant decrease (p<0.05). These results indicated that TGF-β1 contributes to the inherent immune reaction of P. fulvidraco.

Dietary live yeast (Debaryomyces hansenii) provides no advantages in tropical gar, Atractosteus tropicus (Actinopterygii: Lepisosteiformes: Lepisosteidae), juvenile aquaculture

“…The immunological function of b2m is to assist classical major histocompatibility complex (MHC) class I (i.e., MHC-I) molecules in assembling endogenous antigen peptides, forming a trimolecular complex (i.e., pM-HC-I) and then presenting them to the surface of antigen-presenting cells (APCs); through interaction with T cell receptors (TCRs), specific cytotoxic T lymphocyte (CTL) immunity is thus induced (Flajnik and Kasahara 2001;Li et al 2020), and the transforming growth factor β1 (tgf-β1), which is an important multifunctional cytokine involved in the regulation of cell proliferation, differentiation, survival, migration, and apoptosis under physiological and pathological conditions (Qi et al 2016). For example, tgf-β1 acts as an immunosuppressive mediator and inhibits nitric oxide production in TNF-γ-activated macrophages in fish (Wang et al 2017). For instance, the positive effects and benefits of D. hansenii are well known; however, beneficial effects depend on the supplemented concentration (Hai 2015), where overdosing or underdosing results in lower efficacy and unnecessary costs, with low efficiency of the probiotic (Sharifuzzaman and Austin 2017).…”