Page 129 - 《渔业研究》2025年第5期

670 渔 业 研 究 第 47 卷

Screening of acute Vibrio anguillarum-resistant turbot (Scophthalmus
maximus) families and integrated immune expression profiling

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DU Puhe ，XIA Sudong ，WANG Huilin ，GAO Xia ，HUANG Zhihui ，LI Jie 2*
[1. College of Fisheries, Tianjin Agricultural University, Tianjin 300384, China;
2. Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and
Technology (Qingdao), Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs, Yellow
Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China]
Abstract: [Background] Vibrio anguillarum is a significant pathogen of turbot (Scophthalmus maximus),
characterized by rapid disease progression and high mortality rates. Infection in juvenile S. maximus can result
in mortality exceeding 80% within 2−3 days, posing a severe threat to the turbot aquaculture industry.
[Objective] This study aims to screen for immune-related genes against V. anguillarum and disease-resistant
families in S. maximus. [Methods] The study selected eight different families of S. maximus (A−H) and com-
pared their survival rates after artificial infection with V. anguillarum. Additionally, the roles of 12 immune-re-
lated genes (il-1β, mx, nkef, tnf-α, il8r, tlr5, mhc-Ⅰ, mhc-Ⅱ, IgM, tcr, cd4, cd8) and three immune factors (com-
plement C3, LZM, ACP) in the early stages of V. anguillarum infection were analyzed. [Results] The patho-
gen challenge results revealed that the majority of infected fish died within 2−3 days. By 10 days post-infection
with V. anguillarum, family A exhibited a survival rate of 13.15%, family G showed 10.52% survival, while the
other families suffered complete mortality. Immunological factor analysis demonstrated that at 24 hours post-
challenge: family D and family F showed significant increases in complement C3 levels (P<0.05). Family A and
family G displayed significantly elevated acid phosphatase (ACP) activity (P<0.05). qRT-PCR analysis of im-
mune-related genes at 24 hours post-challenge showed followings, family A: significant upregulation of tnf-α,
tlr5, tcr, cd4, and cd8, with tlr5 showing 7-fold increase and cd8 exhibiting 20-fold increase; family G: marked
upregulation of mx, tnf-α, tlr5, tcr, cd4 and cd8, with tlr5 increasing 2-fold and tcr rising 8-fold. In summary,
the robust synergistic response of the immune systems in family A and family G following challenge suggests
their capacity to swiftly recognize pathogens, recruit immune cells, and initiate specific cytotoxicity. Integrating
with the group survival rate data post-challenge, family A and family G exhibit the highest resistance to V. an-
guillarum infection, qualifying them as high disease-resistant potential families against V. anguillarum. For fam-
ily C and family E, significant upregulation of il-1β, tcr, and cd8 was observed; family F showed notable eleva-
tion in C3 content, il-1β, mx, and tnf-α; family H presented significant upregulation of il-1β, tlr5, and tnf-α
genes. However, other pathways (e.g., il8r, cd4) displayed mild responses, indicating that immune activation in
these families was characterized by local pathway dominance. Relying on single or local pathways to combat in-
fection during the early stage of V. anguillarum challenge, these familiess exhibited immune responses with nar-
rower breadth and shallower depth compared to family A and family G, suggesting moderate disease resistance
to V. anguillarum. Family B and family D showed only feeble responses in a few genes (e.g., il-1β in family D)
post-challenge, with overall delayed activation of immune pathways, demonstrating the lowest resistance to
V. anguillarum infection. [Conclusion] In conclusion, family A and family G demonstrate superior suitability
as candidate populations for resistance against acute V. anguillarum infection. Through the study, we have pre-
liminarily identified six immune resistance-related genes (mx, tnf-α, tlr5, tcr, cd4, cd8) that show particular sens-
itivity to V. anguillarum infection in these families. These genes may serve as valuable molecular markers for
selective breeding of V. anguillarum-resistant S. maximus strains, providing critical theoretical data to support
the development of disease-resistant varieties in aquaculture.
Key words: Scophthalmus maximus; Vibrio anguillarum; disease resistance traits; immune response