Molecular characterization of four innate immune genes in Tor putitora and their comparative transcriptional abundance during wild- and captive-bred ontogenetic developmental stages

• Published in: Fish and shellfish immunology reports 2022-12, Vol.3, p.100058-100058, Article 100058
• Main Authors: Tripathi, Priyanka H., Pandey, Anupam, Ciji, Alexander, Pande, Veena, Rajesh, Manchi, Kamalam, B.S., Akhtar, M.S.
• Format: Article
• Language: English
• Subjects: CD36; Gene expression; MYD88; Ontogeny; TLR2; Tor putitora
• ISSN: 2667-0119; 2667-0119
• DOI: 10.1016/j.fsirep.2022.100058

•tlr2, myd88, il-8, and cd36 cDNA were cloned and characterized in Tor putitora.•The constitutive expression of tlr2, myd88, il-8, and cd36 gene was reported at all the developmental stages of T. putitora.•The relative expression of these genes was differentially regulated in the wild- and captive-bred offsprings.•T. putitora larvae obtained from captive-bred brooders showed better immune function. The current study was designed to characterize immune genes and compare their expression during ontogenetic developmental stages in progenies of wild-collected and captive-matured T. putitora. The full-length cDNA sequences of Tptlr2, Tpmyd88, Tpcd36, and Tpil8 were 2814, 1545, 1807, and 653 bp in length, with ORFs of 2379 bp, 855 bp, 1410 bp, and 297 bp, encoding for putative peptides of 793, 284, 469 and 98 amino acids, respectively. The predicted peptide sequences of the genes had high sequence homology and structural conservation with other teleost fishes, especially cyprinids. The expression of Tptlr2 was relatively low in both wild- and captive-bred offsprings during the early embryonic stages, but significantly increased later in development. The mRNA abundance of the Tpmyd88 gene was significantly low until the blastula stage, then increased notably from the gastrula stage to the advanced fry stage. The Tpcd36 expression elevated during later developmental stages, peaking at advanced fry stage in both. On the other hand, expression of Tpil8 was relatively low until the blastula stage and showed a moderate increase from the organogenesis stage onwards in wild-bred offsprings, whereas a significant upregulation was seen in the captive-bred offsprings from the organogenesis stage until the advanced fry stage, with its maximum expression at the pre-metamorphosis stage. Overall, the findings suggest the crucial role of Tpmyd88, Tptlr2, Tpcd36, and Tpil8 in inducing innate immunity in embryonic and larval stages of T. putitora. Further, the considerably higher expression of the immune genes in the embryonic and larval stages of captive-bred offsprings may indicate a stronger immune system.