Establishing LMBV infection resistance models in largemouth bass: Exploration and confirmation of pathways and genes relevant to disease resistance in breeding programs

Abstract

Largemouth bass (Micropterus salmoides) is an important economic freshwater aquaculture species in China, but factors such as disease and a lack of quality seedlings have constrained aquaculture development. In response, we conducted research on breeding for disease resistance and successfully bred a disease-resistant family F1 generation. We used this model to conduct Largemouth bass virus (LMBV) infections to differentiate between resistant and susceptible groups, clarify differences by RNA-sequencing (RNA-seq), and verify disease resistance trait-associated genes using an in vitro infection model. RNA-seq results indicated that pathways such as complement and coagulation cascade, PI3K-Akt, NF-ĸB, and PPAR signaling, and key genes such as C3, PPARα, NFKBIA, JUN, FOS, PI3K, and JAK1 had key roles in LMBV infection resistance. Furthermore, we cloned and preliminarily verified MsPPARα, MsNFKBIA, MsJUN, and MsFOS candidate gene roles in LMBV replication. The results were consistent with RNA-seq data, the low expression of candidate genes effectively inhibited LMBV replication. In conclusion, disease resistance to LMBV is related to lipid metabolism and stabilized inflammatory immune responses. Our study provides a theoretical basis and support for disease-resistance breeding programs for largemouth bass against LMBV infection, and contributes to disease risk and the enrichment of germplasm resources.