Cloning of the Lv-CDK17-like gene in Litopenaeus vannamei and its tissue expression profile in soybean meal-tolerant families

Objective This study aimed to clone the Lv-CDK17-like gene from Litopenaeus vannamei, perform bioinformatic analyses, and investigate its expression profiles across varying levels of soybean meal (SBM) replacement, genetic families, developmental stages, and tissue types, thereby exploring its regulatory role in the shrimp's response to plant-protein-induced dietary stress.

Method Specific primers were designed based on the sequence deposited in NCBI to clone the coding sequence (CDS) of Lv-CDK17-like. Bioinformatic analyses were conducted to characterize its amino acid sequence, protein domain composition, and phylogenetic relationships. Real-time quantitative PCR (qRT-PCR) was employed to evaluate the expression differences of this gene in two shrimp families (Family No. 3 and Family No. 11) under two dietary treatments—20% (T20) and 50% (T50) SBM replacement—at multiple developmental time points. Samples were collected at days 0, 15, 30, 45, and 60; stomach tissue was additionally sampled from day 30 onward; and on day 60, heart, gill, and ventral nerve cord were also collected, totaling seven tissues.

Result The open reading frame (ORF) of Lv-CDK17-like is 1 476 bp in length, encoding a 491-amino acid protein with a predicted molecular weight of 55 kDa and a theoretical isoelectric point (pI) of 8.98. Bioinformatic analysis reveal that the protein contains a single S_TKc domain (spanning residues 162-443), with no transmembrane domains or signal peptides. Phylogenetic analysis indicate that Lv-CDK17-like from L. vannamei is most closely related to that of Macrobrachium nipponense, with a sequence identity of 95.33%. Expression profiling demonstrate that Lv-CDK17-like is regulated by multiple factors: under high SBM replacement (T50), its expression is significantly upregulated in heart and gill tissues. Distinct expression patterns are observed between families—Family 3 exhibits significantly better growth performance under T50 than T20 (final body weight: 3.2 ± 0.6 g in T20 vs. 4.1 ± 0.4 g in T50, representing a 28.1% increase), accompanied by notably high expression in heart tissue at day 60; in contrast, Family 11 performs best under T20, and its expression is significantly suppressed in stomach tissue under T50.

Conclusion The expression pattern of Lv-CDK17-like is closely associated with family-specific growth performance and dietary adaptability, suggesting a critical regulatory role in the shrimp's response to plant-protein dietary stress. This study provides the first systematic characterization of Lv-CDK17-like tissue expression profiles in SBM-tolerant shrimp families, offering theoretical support for the rational application of high plant-protein diets in aquaculture.