Toll-like receptor expression in Pacific white shrimp (Litopenaeus vannamei) reveals differential responses after fungal (Fusarium solani) infection

Understanding the role of the toll-like receptor (TLR) genes in responses to fungal (Fusarium solani) infections is essential to avoid disease outbreaks in the aquaculture industry. This study evaluated the response of eleven TLR genes including protein toll-like receptor-1 (PTL-1), Toll-like receptor 13 × isoform (TLR-13x), Toll-like receptor Tollo-1 (TLR-TO-1), Toll-like receptor Tollo-2 (TLR-TO2), Toll-like receptor Tollo-3 (TLR-TO3), Toll-like receptor Tollo-4 (TLR-TO4), Toll-like receptor 13 (TLR-13), Toll-like receptor 3 (TLR-3), Toll-like receptor 4 (TLR-4), Toll-like receptor 6 (TLR-6), and protein toll-like receptor-2 (PTL-2) to a fungal infection. This study also predicted the transcription factors (TFs) that control their expression in Litopenaeus vannamei. After F. solani infection, the 11 TLR genes were expressed variably in hemocytes, the hepatopancreas, and the gills at various times post-infection. The TLR downstream genes MyD88, IL1, and TNF-alpha were also upregulated after fungal infection. The promoter’s region of eleven TLR genes exhibited 320 TFs. Ten transcription factors (WT-1, C/EBP, GATA, Oct, TBP, Sox, RAP1, SRF, NF-1, and Sp1) were the most abundant among the eleven TLR genes analyzed. Our study provided the first information on the involvement of TLR genes in responding to fungal infection and suggested that they play significant roles in the L. vannamei immune response. Such outcomes would promote the growth and consolidation of the aquaculture industry.