Comparative immunity of Salmo salar and Oncorhynchus kisutch during infestation with the sea louse Caligus rogercresseyi: An enrichment transcriptome analysis.
Caligus rogercresseyi, an ectoparasite affecting the Chilean salmon industry, can cause immunosuppression and physiological stress in farmed fish. Interestingly, coho salmon (Oncorhynchus kisutch) are notably resistant to infestation, whereas Atlantic salmon (Salmo salar) are phenotypically more susceptible to sea lice. However, comparative studies on immune responses to C. rogercresseyi have not been conducted. In this study, Illumina sequencing was conducted to evaluate head kidney and skin samples taken 7 and 14 days post-infestation, yielding a total of 1492 and 1522 contigs annotated to immune-related genes for Atlantic and coho salmon, respectively. Both species evidenced an upregulation of inflammatory genes. Atlantic salmon had highly upregulated TLR22 and MHCII at 14 days post-infestation, while coho salmon had highly upregulated stat5 and il1r transcripts. Fourteen transcripts related to TH1, TH2, TLR, and macrophage responses were corroborated via RT-qPCR. Statistical analyses indicated an upregulation of mmp13, cox2, il10, ccr3, tlr22a2, and tlr21 in Atlantic salmon and of ifnγ, cd83, T-bet, tlr13, and tlr19 in coho salmon. These results suggest strong differences between the Atlantic and coho salmon immune responses, where coho salmon, the more resistant species, presented a primary TH1 response. Additionally, putative roles of TLRs in salmonids against sea lice were evidenced. This study is the first comparative transcriptome analysis that reveals species-specific immune responses in salmons infected with C. rogercresseyi.
Laboratory of Biotechnology and Aquatic Genomics, Department of Oceanography, Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile.
Valentina
V
Valenzuela-Muñoz
Laboratory of Biotechnology and Aquatic Genomics, Department of Oceanography, Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile.
Sebastian
S
Boltaña
Laboratory of Biotechnology and Aquatic Genomics, Department of Oceanography, Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile. Electronic address: crisgallardo@udec.cl.
Cristian
C
Gallardo-Escárate
D000818:Animals; D002677:Chile; D033342:Copepoda / Q000502:physiology*; D004478:Ectoparasitic Infestations / Q000235:genetics / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D005393:Fish Diseases / Q000235:genetics / Q000276:immunology* / Q000469:parasitology; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D007113:Immunity, Innate; D017684:Oncorhynchus kisutch; D020317:Salmo salar; D013045:Species Specificity; D059467:Transcriptome
D029941:Fish Proteins
Atlantic salmon; Caligus rogercresseyi; Coho salmon; Immune response; T(H)1; T(H)2; tlr22a2