Identification, Expression, Characteristic Analysis, and Immune Function of Two Genes in Grass Carp ().

Intensive aquaculture of grass carp often leads to decreased immunity and increased disease prevalence, resulting in economic losses. Improving grass carp immunity is therefore a critical strategy for addressing these challenges. Akirin reportedly participates in myogenesis, growth, and immune responses. However, its role in grass carp remains unclear. Herein, we isolated from the spleen of grass carp and analyzed their tissue-specific expression. Akirin expression was detected following treatment with poly (I:C), LPS, and (). The immunological function of the akirin protein was evaluated in head kidney leukocytes (HKLs). The results revealed that the coding sequence (CDS) of is 570 bp, encoding 189 amino acids. There was one predicted nuclear localization signal (NLS) and two predicted α- helix domains. The CDS of is 558 bp, encoding 185 amino acids. There were two predicted NLSs and two predicted α-helix domains. Tissue-specific expression analysis showed that are widely detected in grass carp tissues. was highly detected in the brain, kidneys, heart, spleen, and gonads, while was highly detected in the brain, liver, gonads, kidneys, spleen, and heart. The mRNA levels of were promoted after treatment with poly (I:C), LPS, and . Recombinant akirin proteins were produced in (). , , , , , , and were markedly increased in grass carp HKLs by treatment with the akirin protein. These results suggest that akirins play a role in the immunological regulation of grass carp.